PROCEEDINGS OF THE 10th International Congress on the Systematics and Ecology of Myxomycetes Turrialba-Costa Rica February 25-28, 2020 General Information The ICSEM 10 took place in the City of Turrialba, approximately 68 km (42 miles) east of San José, the capital of Costa Rica. The Sede del Atlántico of the Universidad de Costa Rica system generously provided the space for the congress. Archaeological documentation of Costa Rica has demonstrated scattered prehispanic presence across the country. However, the most important archaeological features in Costa Rica have been found in Turrialba and have been dated back approximately 10000 years. For this reason, the Costa Rican government, declared Turrialba a city of national archaeological interest (Decreto ejecutivo 14557, 1983). The ICSEM10 logo was based on the Chibcha-influenced petrogliphs found near Turrialba. The campus of the Universidad de Costa Rica system is located about 1.5 km east of downtown Turrialba. Its history is an example of the role of local leaders on the establishment of education in rural Costa Rica and it started operations in 1971 with only 125 students and four professors (History, Spanish, Philosophy and Biology). It is currently located in the former Finca La Hulera (a rubber farm) established by the USDA as the Cooperative Rubber Plant Field Station in the 1940s. This station was intended to do research on genetic improvement of rubber to meet the increasing demand for car tires after the United States lost access to plantations in Southeast Asia during the World War II. Some of the former research buildings still exist on campus. Conceptual cloud of the event Based on keywords, the ICSEM10 was all about… Organization The organization of the ICSEM10 was carried out by Universidad de Costa Rica through activity code 570-B9-7B4 from Finca Experimental Interdisciplinaria de Modelos Agroecológicos (FEIMA). Administrative support was provided by Instituto de Investigaciones en Ingeniería (Engineering Research Institute) and Sede del Atlántico (UCR Turrialba Campus). External support was gently provided by the Myxotropic Project from Real Jardín Botánico de Madrid (Spain), the Japanese International Cooperation Agency -JICA (Japan) and the Cumberland Mountain Research Center from Lincoln Memorial University (USA). The organizing committee was composed by Universidad de Costa Rica´s employees and research associates: Pedro Rojas, Shiori Nakajima, Randall Valverde, Isabel Barboza, Gabriela Bonilla and Carlos Rojas. Acknowledgements The organizing committee wanted to acknowledge the important involvement and support from Werner Rodriguez Montero, Jesús Campos Carpio and Gabriela Bonilla Gamboa. Dedication The ICSEM10 was dedicated to the memory of David W. Mitchell, whose contribution and passion to the study of myxomycetes will always be remembered. Participants The ICSEM10 was attended by people from The Americas, Europe, Asia and Australia. Alejandra Arenas Taborda Angie Natalie Díaz Ruiz Arturo Estrada-Torres Carlos Lado Rodríguez Christina Oettmeier Dmitry Leontyev Eder Flores Ramos Elizaveta Shchepina Frederick William Spiegel Johann Gangl Garrett Taylor Hiroshi Azumo Indira Kalyanasundaram Iryna Yatsiuk Italo Francisco Treviño Zevallos Ivan Garcia Cunchillos Izabel Cristina Moreira J. Carolina Rincón Marín Jan Woyzichovski Kazunari Takahashi Maria Carolina García Chaves Maria Feliciana Benita Eloreta María Isabel del Teso de Prada Martin Schnittler Mercedes Rodríguez Palma (represented) Mia Trappeniers Monica Policina Myriam de Haan Nikki Heherson Dagamac Oleg Shchepin Pedro Rojas Camacho Randall Valverde Gonzalez Randy Darrah Renato Cainelli Ricardo Enrique Morales Hernández Ron Nagorcka Sarah Lloyd Seraoui El-Hacène Shiori Nakajima Solange Xavier dos Santos Steven Stephenson Thomas Edison dela Cruz Tyler Bailey Yuichi Harakon Yury Novozhilov Some images of the event SCIENTIFIC PROGRAM OF THE EVENT Time TUE 25 WED 26 THU 27 FRI 28 8:00-8:30 Registration until 12:00 8:30-9:00 Session 3: Myxomycete Ecology Field trip to La Marta Biological Station Session 5: Myxomycete Morphology and Biology 9:00-9:30 Opening Ceremony 9:30-10:00 Opening Lecture (Dr. Steven L. Stephenson) 10:00-10:30 10:30-11:00 Coffee Break Coffee Break Coffee Break 11:00-11:30 Poster presentation Poster presentation Session 6 (Part 1): Myxomycete Biogeography 11:30-12:00 12:00-14:00 Group Photo/Lunch time Lunch time Lunch time 14:00-14:30 Session 1:Myxomycete Phylogeny and Classification Session 4: Tropical Myxomycetes Session 6 (Part 2): Myxomycete Biogeography 14:30-15:00 15:00-15:30 Coffee Break 15:30-16:00 Closing Lecture (Dr. Arturo Estrada- Torres) 16:00-16:30 Coffee Break Coffee Break 16:30-17:00 Session 2: Associations of Myxomycetes with Other Organisms Special lecture (Dr. Fred Spiegel) Closing ceremony and selection of ICSEM 11 location 17:00-18:00 18:00-19:00 Cultural Activity: Turrialba Municipal Band Cultural Dinner 19:00-20:00 Sessions Posters Lunch Lectures Field Trip Activities INTERNATIONAL CONGRESS ON THE SYSTEMATICS AND ECOLOGY OF MYXOMYCETES Turrialba, Costa Rica – February 25-28, 2019 Program of Activities – ICSEM 10 Tuesday, February 25, 2020 8:00 – Registration 9:00 – Opening Ceremony 9:30 - Opening Lecture S1. On the track of the elusive slime mold (Dr. Steven L. Stephenson, slsteph@uark.edu) 11:00 - Poster presentations P1. New records of myxomycetes for Colombia – Contact: Alejandra Arenas Taborda (alejandra.arenast@udea.edu.co) P2. Do slime molds respond to sound? – Contact: Monica S. Policina (monica_policina@yahoo.com) P3. Incidence of Myxomycetes in the air of Valle de Aburrá, Colombia – Contact: Janeth Carolina Rincón (jcarolina.rincon@udea.edu.co) P4. A new Perichaena foliicolous species (Myxomycetes) from Quercus forests and cloud forests of Mexico – Contact: María Mercedes Rodríguez Palma (mrodriguezpalma@hotmail.com) P5. Long-term evaluation of myxomycetes in a single location: the case of FEIMA in Costa Rica – Contact: Carlos Rojas (carlos.rojasalvarado@ucr.ac.cr) P6. Can the location of the lab affect moist chamber-based data? – Contact: Pedro A. Rojas (pedro.rojas@ucr.ac.cr) P7. Genetic structure of populations of the nivicolous myxomycete Physarum albescens at a large geographical scale – Contact: Oleg Shchepin (ledum_laconicum@mail.ru) P8. Myxomycetes collected at Tanbara Plateau, Gunma Prefecture, Japan – Contact: Hiroshi Suzuki (myxom09@yahoo.co.jp) P9. The diversity of myxomycetes in two forests of the Lesser Khinggan Mountains, China – Participation was cancelled 12:00 – Group Photo 14:00 - Session 1 Myxomycete Phylogeny and Classification Chair (Dr. Oleg Shchepin) O1.The evolutionary history of the order Trichiales in a new multi-gene phylogenetic framework – Contact: Iván García-Cunchillos (igcun@rjb.csic.es) O2. Combining morphology and molecular data to unravel the systematics of the Myxomycetes (Amoebozoa), with special emphasis on the order Physarales – Participation was cancelled O3. How DNA metabarcoding changes our understanding of myxomycete ecology, diversity and distribution – Contact: Oleg Shchepin (ledum_laconicum@mail.ru) O4. Molecular phylogeny of Lepidoderma de Bary and its influence on inter- and infrageneric classification of Didymiaceae – Contact: Oleg Shchepin (ledum_laconicum@mail.ru) O5. Information system on the DNA barcodes of myxomycetes – Contact: Oleg Shchepin (ledum_laconicum@mail.ru) 16:30 - Session 2 Associations of Myxomycetes with Other Organisms Chair (MSc. Johan Gangl) O7. Current and future investigations on the antagonistic activity of Physarum species from Zea mays on plant pathogenic fungi causing mycotoxin contaminations and damping off diseases – Contact: Johann Gangl (johann.gangl@boku.ac.at) O8. Integrated Mechanisms of cellular behavior in Physarum polycephalum: Towards a General Model System for Cognition – Contact: Christina Oettmeier (coettmeier@biophysik.uni- bremen.de) O9. A morphological and molecular study of Myxomycetes collected from Zea mays – Contact: Myriam de Haan (myriam.dehaan@plantentuinmeise.be) 18:00 - Cultural Activity: Turrialba Municipal Band Wednesday, February 26, 2020 8:30 - Session 3 Myxomycete Ecology Chair (Dr. Thomas Edison dela Cruz) O10. Impacts of natural disasters on microbial diversity: a case study of myxomycetes from tropical forests and grasslands in the Philippines – Contact: Thomas Edison E. dela Cruz (tedelacruz@ust.edu.ph) O11. Does myxobiota's response to burning differ with respect to fire intensity? – Contact: Izabel Cristina Moreira (izacristina26@yahoo.com.br) O12. Impact of forest fragmentation to the diversity and distribution of myxomycetes in Mt. Isarog, Camarines Sur, Philippines – Contact: Maria Feliciana Benita M. Eloreta (meloreta67@gmail.com) O13. Association between myxomycetes and the decay stage of coarse woody debris in an evergreen broadleaf forest in warm temperate Japan – Contact: Yuichi Harakon (harakon@nifty.com) O14. Xylophilic myxomycetes: will the largest logs harbor the most, and the most rare, myxomycetes? – Contact: Martin Schnittler (martin.schnittler@uni-greifswald.de) O15. Myxomycetes associated with mahogany trees in Angat Watershed Forest Reserve, Bulacan Province, Philippines – Contact: Monica S. Policina (monica_policina@yahoo.com) 11:00 - Poster presentations P10. Modeling the Myxomycetes - A Proposal for the Teaching and Popularization of Science– Contact: Solange Xavier-Santos (solxav@yahoo.com.br) P11. Dynamization of internationalization agreements in institutions of Higher Education: the case of collaboration between the University of Costa Rica and the University of Antioquia in favor of Myxomycetes biodiversity knowledge in Colombia– Contact: Angie Natalie Díaz Ruíz (natalie.diaz@udea.edu.co) P12. The most well-studied local myxomycete biotas in Russia and Kazakhstan: present state and future directions – Contact: Yuri Novozhilov (yurinovozhilov@gmail.com) P13. Microcosm of myxomycetes (Special exhibit) – Contact: Elizaveta Shchepina (storminka@mail.ru) P14. Myxomycetes recovered from moist chamber cultures of plant remains from 50 families – Contact: Carlos Lado (lado@rjb.csic.es) P15. Diversity of the Myxobiota from Lagunas de Montebello National Park, Chiapas, Mexico – Contact: María Mercedes Rodríguez-Palma (mrodriguezpalma@hotmail.com) P16. Are myxomycetes affected by urban centers? Preliminary evidence using traditional isolation methods – Contact: Randall Valverde (nototriton@hotmail.com) P17. Evaluating the moist chamber protocol for myxomycetes in three different forest types in Costa Rica – Contact: Ricardo Morales (ricardo.morales@ues.edu.sv) 14:00 - Session 4 Tropical Myxomycetes Chair (Dr. Solange Xavier-Santos) O16. Proposal of an online monograph of the Neotropical Myxomycetes – Contact: Carlos Lado (lado@rjb.csic.es) O17. Myxomycetes of tropical forests of Vietnam: what moist chamber cultures can reveal – Contact: Yuri Novozhilov (yurinovozhilov@gmail.com) O18. First reports of Fimicolous Myxomycetes from Brazilian Cerrado and Pantanal Biomes – Contact: Solange Xavier-Santos (solxav@yahoo.com.br) O19. Ten years in Vietnam - observations on diversity and ecology of myxomycetes in Vietnam – Contact: Yuri Novozhilov (yurinovozhilov@gmail.com) O20. Myxomycetes from Africa, an update – Contact: Myriam de Haan (myriam.dehaan@plantentuinmeise.be) 16:30 -Special Lecture S2. A slime-molder’s swan song – the work that is left to be done (Dr. Fred Spiegel, fspiegel@uark.edu) Participation was cancelled 18:00 -Cultural dinner mailto:fspiegel@uark.edu Thursday, February 27, 2020 Field Trip to La Marta Wildlife Refuge During this day, the group will visit La Marta Wildlife Refuge, located near the town of Pejibaye, about 23 km southwest of Turrialba. This place encompasses a large area of premontane wet forest on the Caribbean side of Costa Rica. Based on previous data, the ICSEM10 group will carry out the first myxomycete survey in this area. A list of morphospecies will be generated as a return product to the station and in order to contribute to the knowledge on Costa Rican myxomycetes. What to expect and what is La Marta? The elevation varies between 750 and 1950 meters above the sea. The temperature fluctuates between 18 and 27 degrees Celsius. The relative humidity is high, averaging 90 %. Due to weather and topographical conditions a high number of microhabitats are present. Approximately 40% of the territory is primary forest and the other 60% is covered by secondary forest in various stages of natural regeneration. The Wildlife Refuge is a protected area of approximately 1518 hectares, located in the Jimenez Canton of the Cartago Province. It is one of the most important forests detaining the progress of the spontaneous agricultural colonization in the western slopes of the Cordillera de Talamanca. It is surrounded by five rural communities whose main activities are subsistence farming and ranching . It is also the gateway to the La Amistad and Tapantí/Death Massif National Parks, two of the 12 protected areas that make up the large block of territory incorporated into the La Amistad Biosphere Reserve and Natural World Heritage Site, nominations awarded to the Cordillera de Talamanca by UNESCO. Friday, February 28, 2020 8:30 - Session 5 Myxomycete Morphology and Biology Chair (Dr. Dmitry Leontyev) O21. Secondary capillitium, tertiary stalk and false columella – Contact: Dmitry Leontyev (alwisiamorula@gmail.com) O22. Nivicolous myxomycetes: will the same ribotypes reoccur every year? – Contact: Nikki H.A. Dagamac (nhadagamac@gmail.com) O23. Study on the selection of environmental bacteria by plasmodia – Participation was cancelled O24. Developmental characters and associated symbiont bacterial diversity in essential life cycle stages of one dictyostelids Heterostelium colligatum – Participation was cancelled O6. Automated image analysis in determining the spore size of dark-spore myxomycetes – Contact: Jan Woyzichovski (jan.woyzichovski@uni-greifswald.de) O30. Some hypothesis about columella in the genus Didymium. Contact: Renato Cainelli (myxocare@gmail.com) 11:00 - Session 6 (Part 1) Myxomycete Biogeography Chair (Dr. Nikki Dagamac) O25. Putting slimies on a predictive map: Applying species distribution models on myxomycete research – Contact: Nikki H.A. Dagamac (nhadagamac@gmail.com) O26. “Lowland nivicolous” myxomycetes fruitify more regularly than we think? – Contact: Iryna Yatsiuk (yatsiuk@ut.ee) O27. Myxomycetes associated with Polylepis forests "Queñua" in the Peruvian Andes – Contact: Italo Treviño Zevallos (ifrant01@gmail.com) 14:00 - Session 6 (Part 2) Myxomycete Biogeography O28. Black Sugarloaf, northern Tasmania – a myxomycete hotspot? – Contact: Sarah Lloyd (sarahlloyd@iprimus.com.au) O29. Contribution of the MYXOTROPIC Project to the knowledge of Neotropical Myxomycetes – Contact: Carlos Lado (lado@rjb.csic.es) 15:30 - Closing Lecture S3. From La Malinche Volcano to Tierra del Fuego: Thirty years looking for myxos in Latin America (Dr. Arturo Estrada-Torres, arturomixo@hotmail.com) 16:30 - Closing ceremony and selection of ICSEM 11 location Abstracts All abstracts (including those from people who cancelled) were included. Due to a virus epidemic in China, our Chinese colleagues could not come to the ICSEM10 and due to health reasons (personal or relatives) some of our friends had to cancel in the weeks before the event. We deeply regret these issues and wanted to include the interesting contributions that could not be presented. Special Lectures S1. On the track of the elusive slime mold Steven L. Stephensona aDepartment of Biological Sciences, University of Arkansas, Fayetteville, Arkansas 72701 In the fall of 1974, while taking a mycology course at Virginia Tech taught by Dr. Orson Miller, the author was first introduced to the slime molds (or myxomycetes, as they are known to people who collect and study these organisms). He began noticing myxomycetes in the field and soon discovered that their ecology was an understudied subject. With his background in forest ecology (the research the author carried out for both his M.S. and Ph.D. degrees involved studying the upland forests of the Central Appalachians), he was well prepared to undertake studies of myxomycete ecology. In the summer of 1982, with the support provided by a post-doc from the University of Virginia Mountain Lake Biological Station, a series of such studies began that would extend over the next four decades. These studies were carried out in a number of different areas of the world, including Alaska, Argentina, Australia, Costa Rica, Ecuador, India, Kenya, Mexico, New Zealand, northwestern Montana, Puerto Rico, subantarctic Macquarie Island and Thailand. The primary emphasis of these studies has been directed towards developing a better understanding of the distribution and ecology of myxomycetes in terrestrial ecosystems. These efforts have been funded in part by grants from the National Science Foundation, the National Geographic Society and a number of other institutions and agencies. Moreover, over his career, the author has been assisted in his studies by a considerable number of individuals. This presentation represents an overview of the journey the author has taken since he first became aware of the myxomycetes. Keywords: biodiversity, ecology, myxomycetes, terrestrial ecosystems S2. A slime-molder’s swan song – the work that is left to be done Frederick W. Spiegela aDepartment of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA As this is my last year as a formal academic researcher interested in mycetozoan members of Amoebozoa, I would like to suggest to the younger members of our community some areas of research that could be valuable for the discipline of Biology as a whole. The life repertoires of mycetozoan amoebozoans are among the most complex found in Amoebozoa. They involve fruiting in all cases, and the trophic stages can involve a number or different kinds of amoebae and/or amoeboflagellates as well as a number of kinds of cysts. The most complex life repertoires involve a complex alternation between an amoeboflagellate and an obligate amoeba with sex being a part of the scene. We now know that the amoebozoan slime molds are not a monophyletic group; rather, they are scattered throughout the amoebozoan Tree of Life in both major branches. However, the most common method of fruiting, sporocarpy, is unique to Amoebozoan among eukaryotes. We have suggested that this type of life repertoire could be the ancestral state for Amoebozoa. Were that actually the case, this would mean that the most common pattern of evolution in Amoebozoa is from complexity to simplicity of structure and life repertoire. While this is an interesting hypothesis, it has yet to be rigorously tested. This presentation will focus on several aspects of the mycetozoans that need to be fully examined in order to test the hypothesis, and it will become clear that a rigorous approach must include both classical and next-generation approaches to biological research. Key words: Amoebozoan mycetozoans, classical biology, next-generation biology, sporocarpy, life repertoires S3. From La Malinche Volcano to Tierra del Fuego: Thirty years looking for myxos in Latin America Arturo Estrada-Torresa, Carlos Ladob, Diana Wrigley de Basantab a Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, 90,070, Mexico. b Real Jardín Botánico, CSIC, Plaza de Murillo 2, 28014 Madrid, Spain. Latin America is in one of the most biodiverse regions in the world, with six of the so-called mega- diverse countries: Brazil, Colombia, Ecuador. México, Perú and Venezuela. Its location includes three major biogeographic regions and all the main ecosystems of the world, from the evergreen Amazonian forests to the coniferous forests in the high mountains of Mexico, and from the driest hot deserts on the planet in northern Chile to the cold arid areas of Patagonia. Latin America is home of infinity of emblematic lineages that have borne and diversified in their lands, such as cacti, agaves, bromeliads and hummingbirds, among many others, that contribute to their biological attractiveness. Despite its high biological diversity, the first record of a myxomycete was made until the early nineteenth century, and since this date to 1976, year in which Farr published her monograph in the Flora Neotropica series, 250 species were recorded from this geographic area. In 1988, our work group began its explorations in this important geographical area. In the beginning, the fir forest of La Malinche National Park, in central Mexico, was its objective, registering more than 170 species that make it currently recognized as one of the world hot spots of myxomycete diversity. In the coming years, this action extended to other areas of Mexico, exploring 20 of its 32 states. Later, this exploration was extended to Argentina, Chile and Peru, emphasizing the study of the diversity of myxomycetes in arid environments, in addition to the fact that, in collaboration with colleagues from other institutions, we also made excursions to some areas of Brazil, Costa Rica, Cuba, Ecuador, Guatemala and Honduras. With thousands of kilometers traveled, hundreds of field collections and dozens of moist chambers of various substrates, our team has contributed substantially to the knowledge of Latin American myxomycetes. The main achievements of our work are: a) The enrichment of scientific collections with material of great documentary value mainly in Spain and Mexico, but also in the United States and Peru; b) The substantial increase in knowledge of the myxobiotas of the countries visited, mainly Argentina, Chile, Ecuador, Mexico and Peru; c) The description of twenty-seven species from the region, in several genera; d) A better understanding of the diversity, systematics, ecology and distribution of myxomycetes in arid zone environments; e) The clarification of the identity of the enigmatic genus Schenella; and f) The discovery of unique substrates for the development of myxomycetes, such as lianas and the remains of cushion-like plants from the cold regions of the Andes. Undoubtedly, much more needs to be done in this incredibly diverse region of the planet, but the research carried out so far is an example that teamwork will always be more productive and enriching. Keywords: biodiversity, distribution, Neotropics, teamwork Posters P1. New records of myxomycetes for Colombia Alejandra Arenas Tabordaa, Angie Natalie Díaz Ruíza, María Carolina García Chavesa, Carlos Rojasb aSchool of Microbiology, University of Antioquia. Medellín, Colombia bEngineering Research Institute and Department of Biosystems Engineering, University of Costa Rica, San Pedro de Montes de Oca, Costa Rica Microbial biodiversity has become increasingly interesting responding to the recognition of the fundamental role of microorganisms in the biogeochemical balance of ecosystems. However, a great variety of environments whose micro-biodiversity has been very little studied exist in the Neotropics. The low representativeness of research on range records of myxomycetes in this region, related to other latitudes, constitutes a good example of it. Therefore, the current study focused to contribute to the description of the pluralism of this group of microorganisms in Colombia. For so doing, two collections were made, one in the coastal habitat in Cartagena, and another in an urban system in Medellín. In Cartagena, dried leaves were collected in several city parks, which were incubated for a month in wet chambers to promote the development of visible myxomycetes structures. In Medellín, the sampling was carried out in green areas of the University of Antioquia, by collecting plant material in which myxomycetes structures were observed. The specimens obtained from both collections were taxonomically identified from the microscopic observation of the fruiting body. From the samples of Cartagena, 7 specimens were found; and, from the collection made in Medellín, a total of 13 specimens were obtained, of which 4 make up new reports for Colombia (Comatricha nigra, Perichaena vermicularis, Cribraria violacea y Arcyria minuta). Taking into account that new species were found with a low sampling effort in this study, it can be stated that biodiversity of myxomycetes in Colombia has been underestimated. It is thus necessary to move forward in this line of research to cop the knowledge gap about the forms of these microorganisms in the Neotropics. Keywords: biodiversity, myxomycetes, Neotropics, Colombia P2. Do slime molds respond to sound? Monica S. Policinaa, Thomas Edison E. dela Cruza aThe Graduate School and Fungal Biodiversity, Ecogenomics, and Systematics Group, Research Center for the Natural and Applied Sciences, University of Santo Tomas, España Blvd. 1008 Manila, Philippines Sound stimulation has been previously reported to influence growth and behavior of animals and plants. Studies also showed the effects of sound including noise to microorganisms such as bacteria and microalgae. Does sound also stimulate or retard the growth of myxomycetes? In this study, we tested whether slime molds just like any other organisms respond to sound, particularly to static noise. We initially cultured the plasmodia of the model myxomycete, Physarum polycephalum, on 1.5% water agar (WA-O) supplemented with 2% (w/v) powdered oatmeal. Plasmodial fronts were cut as a 6-mm diameter agar block and placed at the center of WA-O (12 plates per sound treatment). Culture plates were then placed in a sound chamber setup with speakers at opposite ends. P. polycephalum was then continuously exposed to the static sound (or noise) for 3 days. A similar set-up in the sound chamber without any sound served as control. Plasmodial growth was observed and photographed every 6 hours and then, the plasmodial front was measured after 24 hours. Generally, we observed a faster migration of plasmodia in the absence of noise. An average distance of 7.708 mm was measured when P. polycephalum was exposed to the static noise. In contrast, the plasmodia travelled an average distance of 9.984 mm in the absence of sound. We are currently testing the responses of P. polycephalum to different types of sound (or music). Our study highlighted the possible effects of sound, particularly noise, to the growth and behavior of myxomycetes. Keywords: myxomycetes, noise pollution, plasmodial growth, sound stimulation P3. Incidence of Myxomycetes in the air of Valle de Aburra, Colombia Janeth Carolina Rincóna, María Carolina García Chavesa, Carlos Rojasb aSchool of Microbiology, University of Antioquia. Medellín, Colombia bEngineering Research Institute and Department of Biosystems Engineering, University of Costa Rica, San Pedro de Montes de Oca, Costa Rica During the last years, the city of Medellín, located in the Valle de Aburrá on the Central Mountain range from Los Andes, has suffered significant air quality problems. Factors related to the topography of the valley, its meteorological characteristics, and the increase in the emission of pollutants favor the accumulation of pollutants in the air of the metropolitan area. This implies that a great number and diversity of particles are expected to be suspended in the air and dispersed by the winds. However, most air studies in the metropolitan area have focused on monitoring the concentration of particulate matter (PM 2.5), because of the risk that this type of contaminants represents for human health. Consequently, the dynamics of transport, dispersion and deposition of biotic particles in the air of Medellín are unknown. Therefore, in this work we proposed to describe the movement of Myxomycetes spores in the Valle de Aburrá caused by transport. To meet this objective, 70 air traps were exposed for 3 months at 3 points along the valley (north, center and south) and another 24 at a rural point outside the urban area. In order to capture the spores carried by the wind that blows in different directions, groups of 6 traps were placed towards the 4 cardinal points. After the exposure, the content of the traps were incubated in wet chambers for 4 months. These cameras were monitored every 15 days to record the presence of Myxomycetes and material with fruiting bodies was collected for identification. A higher incidence of Myxomycetes was found in the traps located on the north front for one of the sampling points in the urban area and, on the east front for the rural point; which corresponds to main wind direction at these two points. The above indicates that propagules are transported following the pattern of winds. However, in the other two points of the urban area, equal incidence values were found on the 4 fronts. This could indicate that at these points the concentration of propagules is as high that it confuses the wind pattern. This hypothesis makes sense if one takes into account that the wind in the Valle de Aburrá has predominantly a north-south direction, and therefore there is usually a higher concentration of pollutants in the southern area of the valley, where these 2 points of sampling were located. With this work we are providing the first data that demonstrate the presence of Myxomycetes in the air of the metropolitan area of the valley and, we present the first evidence that its propagules are transported by mean air flow along the valley. Keywords: air, Medellín, spores, transport, wind pattern P4. A new Perichaena foliicolous species (Myxomycetes) from Quercus forests and cloud forests of Mexico María Mercedes Rodríguez Palmaa,c, Gabriel Moreno Horcajadab, Misael García Floresc, Angélica Romero Rodríguezd aLaboratorio de biodiversidad, Centro de Investigación en Ciencias Biológicas, Universidad Autónoma de Tlaxcala. Km. 10.5 carr. San Martín Texmelucan-Tlaxcala, Ixtacuixtla, Tlaxcala. 90120 bDpto. Ciencias de la Vida (Botánica), Fac. Biología. Universidad de Alcalá. Alcalá de Henares, 28805. Madrid, Spain cMaestría en Biotecnología y Manejo de Recursos Naturales, Universidad Autónoma de Tlaxcala dCentro de Investigación en Biotecnología Aplicada. Instituto politécnico Nacional. Ex Hacienda S. J. Molino. Km. 1.5 carr. Tecuexcomac-Tepetitla, Tlaxcala. 90700 The genus Perichaena (Trichiales-Myxomycetes) was originally proposed by Fries in 1817. It is represented by both sporocarpic and plasmodiocarpic forms, with thick persistent peridium, and spores from yellow to reddish brown in mass. Most species have a well-developed capillitium formed by roughened tubes, with warts, spines or rings and totally lack spiral bands. Some species have a wide distribution, while others are only known from the type locality. During of the studies on myxobiota in different localities in Mexico, a stipitate species of the genus Perichaena was detected both in the field and in moist chamber cultures, growing on leaves of Quercus rugosa, in the state of Tlaxcala and in a cloud forest in the state of Chiapas. Initially, it was considered that the specimens corresponded with some species of the genus Trichia because of their macromorphological appearance, however, in a quick review of the micromorphological characters, particularly of the capillitium, it could be detected that it corresponded with a species of the genus Perichaena not yet described for science. The characterization of Perichaena sp. was performed considering macro and micromorphological structures through clear field microscopy and scanning electron microscopy (SEM). It was compared with specimens of nearby species deposited in the TLXM herbarium of the Tlaxcala University and the AH herbarium of the Alcalá de Henares, University, Madrid, Spain. Perichaena sp. grows on the underside of leaves of Quercus rugosa and in litter. It has been collected in 2017, 2018 and 2019. It is characterized by stipitated sporocarps, with blackish stipe, internal peridium with thick ridges and a low-marked low reticulum and by the reticulated capillitium with few warts. Morphological characters were constantly present in both specimens obtained in the field as well as those in the moist chamber. At least other six Perichaena species with a well developed stipe have been described, however, all of them show morphological characters that differ from the species found in this study. The validity of the new species should be complemented with a molecular phylogenetic analysis as suggested in recent studies. Keywords: eumycetozoa, moist chambers, taxonomy P5. Long-term evaluation of myxomycetes in a single location: the case of FEIMA in Costa Rica Carlos Rojasa,b, Pedro A. Rojasa, Shiori Nakajimaa,b,c aEngineering Research Institute, University of Costa Rica, San Pedro de Montes de Oca, 11501- Costa Rica bFinca Experimental Interdisciplinaria de Modelos Agroecológicos, University of Costa Rica, San Pedro de Montes de Oca, 11501-Costa Rica cJapanese International Cooperation Agency (JICA), San Pedro de Montes de Oca, 11501-Costa Rica Few myxomycete studies have evaluated ecological patterns in one single location using a strong collecting effort. During two complete years, myxomycete fruiting bodies were looked for in field conditions on a monthly basis in selected locations within a 28-hectare moist premontane tropical forest patch in Costa Rica. An effort of 2880 minutes of field work, equivalent to 48 hours, were used for that task. Additionally, 864 samples for moist chamber cultures were taken to the laboratory for isolation. A total of 58 species, or approximately 6% of the world's morphological biodiversity, was recorded in the studied place. Most species did not show any type of “phenological” pattern and were recorded at different times. The only species that was recorded in every single month of sampling was Hemitrichia calyculata. Arcyria denudata and Ceratiomyxa fruticulosa were recorded most of the time. Both patterns of species richness and taxonomic diversity varied over time but showed low values during the middle part of the year, particularly around July. The drier months, between December and April, showed the highest values. When the data was analyzed using a series of environmental and structural parameters associated with the forest, some interesting patterns of fructification were observed. This type of long-term studies on myxomycetes are important to understand the effect of external and internal fluctuations on the forest and how their relationship may ultimately affect fructification patterns and ecological strategies on myxomycetes. Keywords: climate change, field sampling, microbial ecology, monitoring P6. Can the location of the lab affect moist chamber-based data? Pedro A. Rojasa, Carlos Rojasa,b aEngineering Research Institute, University of Costa Rica, San Pedro de Montes de Oca, 11501- Costa Rica bFinca Experimental Interdisciplinaria de Modelos Agroecológicos, University of Costa Rica, San Pedro de Montes de Oca, 11501-Costa Rica The use of moist chambers to generate data on myxomycetes has been very common during recent decades. Despite several shortcomings at the taxonomic level due its inherent bias on morphological information, the usefulness of this technique for the generation of data from most parts of the world is still recognized. However, few studies have critically analyzed the effect of laboratory location on the results obtained using this technique. In the present study, three sets of tropical substrates were collected and divided in two twin subsets that were placed in moist chambers in two laboratories separated by one mountain. Due incident winds and moisture, one side of the mountain was moister and cooler than the other. Results showed that general ecological patterns such as diversity or species richness were similar among datasets, but composition of species was slightly different. Some species such as Arcyria afroalpina, Didymium clavus, Clastoderma debaryanum and Physarum superbum were only recorded in one laboratory. The internal temperature of the moist chamber was higher on the dryer side of the mountain but both pH and humidity were similar between the two sets. These results show that even though the two laboratories yielded highly comparable data, external factors such as topography and climate may play a role in the generation of myxomycete information using moist chambers. This type of information could be useful to understand species sensitivity to external conditions when forming fruiting bodies and relevant in the context of climate change monitoring. Keywords: bias, geography, methodology, standardization P7. Genetic structure of populations of the nivicolous myxomycete Physarum albescens at a large geographical scale Oleg Shchepina,b, Yuri Novozhilova, Ilya Prikhodkoa, Vladimir Gmoshinskiyc, Mathilde Borg Dahlb, Nikki H. Dagamacb, Martin Schnittlerb aLaboratory of Systematics and Geography of Fungi, Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Str. 2, St. Petersburg 197376, Russia bGeneral Botany and Plant Systematics, Institute of Botany and Landscape Ecology, University Greifswald, Soldmannstr. 15, Greifswald 17487, Germany cFaculty of Biology, Lomonosov Moscow State University, Leninskie Gory Str. 1, Moscow 119991, Russia We investigated genetic structure of populations of the nivicolous myxomycete Physarum albescens by sequencing field collections of fruit bodies from different mountain systems of Northern Hemisphere for three independent genetic markers (18S RNA, EF1A, COI). For several regions of Eurasia, the occurrence data of environmental 18S rRNA gene sequences from DNA metabarcoding studies complement the sporocarp-based data. Despite the large genetic diversity discovered, all studied specimens form a monophyletic clade and possess a short spliceosomal intron in the first half of EF1A gene that is absent in all other sequenced species of Physarales and Stemonitidales. However, the structure of the phylogeny and the observed recombination pattern of three independently inherited gene markers can be best explained by presence of at least 17 cryptic biospecies within Ph. albescens. Most of the 17 putative biospecies have a limited geographic distribution and occur only in one or two studied regions, and in most of the studied regions at least two of them coexist. Some of them can be clearly separated into biospecies with ‘boreal’ or ‘southern’ ranges. In addition, the results of genotyping of 97 specimens from several most abundant biospecies from different regions will be discussed with a special accent on the question of clonal reproduction in natural populations of myxomycetes.The authors are grateful to Marianne Meyer, Paulina Janik, Yuka Yajima, Renato Cainelli and other researchers for providing specimens and photos. We acknowledge support from the Russian Foundation of Basic Research (18-04-01232 А) and the German Research Council (DFG: SCHN1080/2-1, RTG 2010). Keywords: biogeography, cryptic speciation, DNA barcoding, genotyping, myxomycetes P8. Myxomycetes collected at Tanbara Plateau, Gunma Prefecture, Japan Hiroshi Suzukia, Hiromitsu Hagiwaraa a The Japanese Society of Myxomycetology, 17-3-1, Asahi, Echizen-cho, Nyu-gun, Fukui, Japan The Tanbara Plateau is located in Kamihotchi-machi, near the city of Numata and oscillates between 1150 and 1600 m of elevation. This plateau is about 900 ha in dimension, has a cold temperate climate and its forest is composed primarily by beech trees. After an investigation was carried out in the summer of July 2018, we have confirmed 42 species of myxomycetes within 14 genera for this area (including the genus Ceratiomyxa). All vouchers were deposited in the Gunma Museum of Natural History and we have confirmed that in a previous expedition in 1995, 59 species within 15 genera were collected. We would like to thank Tomoko Anezaki and Satoshi Ito for providing access to this area for collection. We also acknowledge the guidance of the Society for Nature Appreciation of Tonenumata and thank the identification provided by Yukinori Yamamoto and Jun Matsumoto. Keywords: Japan, myxomycetes, Tanbara, Ursus thibetanus P9. The diversity of myxomycetes in two forests of the Lesser Khinggan Mountains, China Shu-Yan Liua,b, Feng-Yun Zhaoa, Yu Lia aEngineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130118, China bCollege of Plant Protection, Jilin Agricultural University, Changchun 130118, China Myxomycetes are widely distributed in forest ecosystems and play an important role in nutrient cycling. The diversity and distribution of myxomycetes in two forests of the Lesser Khinggan Mountains, China were examined in Tangwanghexing’anshilin Forest Park and Shengshan National Nature Reserve. A total of 248 samples of myxomycetes were collected and identified to 44 species belonging to 17 genera of eight families in four orders based on morphological characteristics. Ten new species were recorded in Heilongjiang Province, such as Craterium dictyosporum, Physarum album and Reticularia splendens var. jurana. The species diversity of myxomycetes was higher in Tangwanghexing’anshilin Forest Park (36 species) than in Shengshan National Nature Reserve (25 species). Among the 44 species, 17 species were found in both sites and the composition similarity (CS) was 55.7%. Physarum viride was the most dominant species in mixed coniferous and broad-leaved forests. Hemitrichia serpula was the most dominant species in Pinus koraiensis forest. This study suggests that vegetation type has an important influence on the species composition and diversity of myxomycetes. Keywords: ecology, distribution, temperate forests P10. Modeling the Myxomycetes - A Proposal for the Teaching and Popularization of Science Solange Xavier-Santosa,b, Jéssica Conceição Araújoa,b, Pedro Oliveira Paulob aLaboratory of Basic and Applied Mycology and Scientific Divulgation. University (UEG), Anápolis Campus of Exact and Technological Sciences (CCET), Anápolis-Goiás, Brazil bGraduate Program Professional Master in Science Teaching (PPEC) - Goiás State University (UEG), Anápolis Campus of Exact and Technological Sciences (CCET), Anápolis-Goiás, Brazil. Although textbooks remain the main pedagogical resource used by science teachers in basic education, didactic models can be an additional resource at different levels of education, providing more meaningful learning, especially in the case of abstract and difficult to understand content in Science Teaching. Models have also been used to promote the popularization and popularization of science, a topic that has received more interest in recent years in Brazil. However, much knowledge remains restricted to the scientific community. Such as knowledge about myxomycetes (Eumycetozoa, Amoebozoa), a group of living beings found in a wide diversity of habitats containing decaying organic matter, including residential yards and public parks. However, due to the ignorance of the group by the population, including many educators, the myxomycetes are still very neglected in Basic Education. In this sense, we developed didactic models, based on alternative materials, that represented species of myxomycetes common in Central Brazil and provide the tutorial of this procedure in digital format (video) in social media, including educational sites. Three species of myxomycetes (Hemitrichia calyculata, Diachea leucopodia and Diderma effusum) that have typical sporocarps and can be found in natural and anthropized areas were modeled. Images and descriptions of the species were researched in order to verify morphology details to support the development of the models. Molds were made of cardboard, which were used to make the models, which were sewn into fabric (felt) and filled with recycled silicone foam. The finishing was done using paint, hot glue and glitter. The model also included the natural substrate of these species, a wood trunk, which was characterized using Pinus spp bark. and mosses, to attribute reality to form. The modeling steps were filmed and compiled into a do- it-yourself step-by-step video. By providing models and step-by-step modeling of these living beings in digital (video) format on social media, we hope to contribute to the popularization of knowledge about these living beings in society, as well as providing a teaching tool with several possibilities for use in science education. Keywords: didactic model, myxomycetes, science teaching P11. Dynamization of internationalization agreements in institutions of Higher Education: the case of collaboration between the University of Costa Rica and the University of Antioquia in favor of Myxomycetes biodiversity knowledge in Colombia Angie Natalie Díaz Ruíza, Alejandra Arenas Tabordaa, María Carolina García Chavesa, Carlos Rojasb aSchool of Microbiology, University of Antioquia. Medellín, Colombia bEngineering Research Institute and Department of Biosystems Engineering, University of Costa Rica, San Pedro de Montes de Oca, Costa Rica Internationalization processes in higher education institutions have emerged in response to globalization and are an excellent strategy to improve the quality of education. The University of Antioquia (UdeA) intend "to project the Institution internationally, through agreements and exchanges of scientific, academic and cultural collaboration, to international community organizations and foreign universities". Consequently, the International Relations Department signs international agreements with universities and other institutions on an ongoing basis. However, in many cases, initiatives for the execution of activities that promote the collaboration of already signed agreements are lacking. Therefore, with this poster we seek to illustrate the way in which simple and low-cost academic strategies can make these agreements dynamic. An example of this are the activities that have been developed within the framework of an agreement signed between UdeA and the University of Costa Rica (UCR). The processes started in 2018 with a talk given to motivate students and professors of the UdeA to propose and execute projects on the diversity, abundance and distribution of Myxomycetes in Colombia. As a product of this first interaction, a student from UdeA started to work on her proposal about the incidence of Myxomycetes in the air of Medellín, thus achieving the reactivation of the agreement between UdeA and UCR. On a second phase, a group of students assembled and set-up an experiment with air traps for Myxomycetes in the city of Medellín. Then in 2019, students and teachers of Biology and Microbiology at UdeA attended a 3-day workshop to discuss theoretical and practical aspects in the study of Myxomycetes. Other activities planned within the agreement include the participation of a professor from UCR in the Medellín Microbial Meeting event and, the signing of a specific agreement in order to establish a project that aims to analyze the potential of Myxomycetes as biological indicators of urban pollution processes. This experience shows that the development of simple activities and the transfer of knowledge between institutions of higher education allow the dynamization of agreements, expand the themes and objects of study of research groups, close gaps in scientific communication and promote the participation of students in research projects of global interest. Keywords: agreement, higher education, international cooperation, myxomycetes, UCR, UdeA P12. The most well-studied local myxomycete biotas in Russia and Kazakhstan: present state and future directions Yuri Novozhilova, Martin Schnittlerb, Oleg Shchepina,b, Vladimir Gmoshinskiyc, Inna Zemlyanskayad, Anastasia Vlasenkoe, Fedor Bortnikovc, Ilya Prikhodkoa, Andrey Matveevc, Nadezhda Fedorovaf aLaboratory of Systematics and Geography of Fungi, Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Str. 2, St. Petersburg 197376, Russia bGeneral Botany and Plant Systematics, Institute of Botany and Landscape Ecology, University Greifswald, Soldmannstr. 15, Greifswald 17487, Germany cLomonosov Moscow State University, Leninskie Gory Str. 1, Moscow 119991, Russia dVolgograd State Medical University, Pavshikh Bortsov Square 1, Volgograd 400131, Russia eMain Siberian botanical garden of the Siberian branch of the Russian Academy of Sciences, Zolotodolinskaya Str. 101, Novosibirsk 630090, Russia fSaint Petersburg State University, Universitetskaya Emb. 7/9, St. Petersburg 199034, Russia To date, about 450 morphospecies of myxomycetes of 53 genera have been registered in Russia and former Soviet republics. The last two decades have seen a rapid increase in the number of publications on the assessment of diversity, distribution and ecology of myxomycetes in various Russian regions, representing most Eurasian biomes. However, the degree of completeness of these surveys varies greatly depending on the methods of collecting sporocarps (field collections or/and specimens obtained from moist chamber cultures), the intensity of research, the time of collection, the experience and professional competence of collectors. To select the most well-studied regions we applied the following criteria: 1) intensive field studies of myxomycetes conducted for at least 2-3 years in the same area at different times of the year; 2) all occurrences of fruit bodies registered during the field surveys; 3) field collections accompanied by moist chamber cultures; 4) species coverage at least 75% (Chao1 index). Based on these criteria, we have selected a number of data sets on the species diversity of myxomycetes of various biomes in Russia and Kazakhstan (some of them are listed below), where we have conducted intensive research over the past 20 years. Arctic mountain tundra and forest tundra: Khibine Mts., Kola Peninsula (32 species, including nivicolous). Subalpine and alpine communities of North Caucasus, Teberda Biosphere reserve (39 species, including nivicolous). North taiga: Khibine Mts. and Laplandskiy Biosphere reserve (91 species). South lowland taiga, Central Forest Biosphere reserve, Tver’ region (176 species). South continental mountain taiga, Eastern Sayan mountain ridge, Siberia (123 species). Dry pine forests of south Altay (72 species). Dark wet taiga and mixed forests of Altay Mts. (159 species). Broad- leaved and mixed forests of North Caucasus, Teberda Biosphere reserve (134 species). Broad-leaved and mixed forests of Far East, Sikhote-Alin Biosphere reserve, Kedrovaya Pad’ reserve (209 species). Riparian broad-leaved forests of Volga-Akhtuba lowland, Volgograd region (160 species). Riparian willow forests of south Siberia (70 species). Steppes: Altay Kray, Siberia (45 species), Caspian lowland, Russia (99 species). Deserts: Caspian lowland, Russia (50 species). In addition, intensive research was carried out in steppes (103 species) and deserts of Kazakhstan (48 species). Despite this, the knowledge about myxomycetes of this part of Eurasia is still very far from being complete. Molecular phylogenetic studies and DNA metabarcoding have made significant changes in the taxonomy of myxomycetes and revealed a greater number of closely related (cryptic) species. This update will inform about the opportunities, challenges and future directions of studies exploring ecology and diversity of myxomycetes in Russia. We acknowledge support from the Russian Foundation of Basic Research (18-04-01232 А), and the program of the Komarov Botanical Institute RAS (АААА-А19-119020890079-6) and the German Research Council (DFG: SCHN1080/2-1, RTG 2010). Keywords: biodiversity, completeness, herbaria, species inventory P13. Microcosm of myxomycetes Elizaveta Shchepinaa aFreelance artist, https://www.artstation.com/ion_storminka On the ICSEM 10 I would like to present a series of paintings showing a journey into the microcosm of myxomycetes. What if a person had an opportunity to be as tiny as a springtail and look at the myxomycete colonies not down from the top but up from the bottom? In this series I want to emphasize the monumentality and beauty of the world of myxomycetes, depict them as landscapes performed in the technique of digital painting printed on canvas. The series will show the selection of species from different geographical locations and ecological groups (e.g., nivicolous species, tropical species, Kamchatka species). I would like to thank my husband Oleg Shchepin for introducing me into the amazing world of myxomycetes. Keywords: art, digital painting, myxomycetes P14. Myxomycetes recovered from moist chamber cultures of plant remains from 50 families Diana Wrigley de Basantaa aReal Jardín Botánico, CSIC, Plaza de Murillo 2, 28014 Madrid, Spain The results of moist chamber cultures of plant remains from over 170 plant species in more than 50 families have been examined for patterns in frequency of appearance, productivity, substrate preference, pH tolerance or other factors affecting the recovery of myxomycetes. The benefit of the moist chamber culture technique is that it is standardized in terms of size of sample, collection and preparation technique and so many variables of the cultures are controlled, and this enables a more direct analysis than looking at mixed data sets or field collections only. The technique also eliminates the bias of ephemerality that affects field collecting and allows detection of many minute species. Results of 1600 cultures of plant remains from 10 countries on 4 continents have been scrutinized and comments and conclusions will be presented in this contribution. This work would not have been possible without the support of the Myxotropic Project I-VI [REN2002-00445/GLO to PGC2018-094660-B-I00 (MCIU/AEI/FEDER, UE)] http://www.myxotropic org Keywords: culturing, standardization, techniques P15. Diversity of the Myxobiota from Lagunas de Montebello National Park, Chiapas, Mexico Misael García-Floresa, María Mercedes Rodríguez-Palmaa,b, Sandra García de Jesúsc, Yolanda Nava Gutiérrez a,b a Maestría en Biotecnología y Manejo de Recursos Naturales, Universidad Autónoma de Tlaxcala. b Laboratorio de Biodiversidad, Centro de Investigación en Ciencias Biológicas, Universidad Autónoma de Tlaxcala. Km. 10.5 de la carretera San Martin Texmelucan-Tlaxcala S/N, C.P. 90120, Ixtacuixtla de Mariano de Matamoros, Tlaxcala, México. c Laboratorio de zoología, Licenciatura en Biología, Universidad Autónoma de Tlaxcala. Km. 10.5 de la carretera San Martin Texmelucan-Tlaxcala S/N, C.P. 90120, Ixtacuixtla de Mariano de Matamoros, Tlaxcala, México. Although studies of myxomycetes in Mexico have increased in recent years, most have focused on conducting inventories of species and just a few of them have addressed ecological aspects, to understanding the diversity patterns of these organisms, especially in the Mexican Neotropic. The objective of this work was to evaluate and compare the diversity patterns in myxomycete communities developing in cloud and Pinus-Quercus forests from Lagunas de Montebello National Park, Chiapas (LMNP). To carry out the study, three plots of 10 x10 m were established in the sites near the lakes: Montebello, Pojoj, San Rafael and Cinco Lagos. A directed and intensive sampling of reproductive structures in the field was carried out. To complement the sampling, six different substrates were collected, in order to obtain myxomycetes in the laboratory, using the moist chamber (MC) technique. The specimens obtained were identified with the help of specialized taxonomic keys. Myxomycete communities were characterized by the LMNP and for each study site. The ecological analysis was carried out through the evaluation of, percentage of positive moist chambers, richness, abundance, diversity of species and the species/genus ratio (E/G) for each substrate and locality. A comparative analysis was performed between the myxomycete communities, present in each sampling site through the ecological variables obtained. A total of 67 species and one variety were found, belonging to 21 genera, nine families and six orders. 44 species were collected in the field and 51 in MC. 27 species are registered for the first time to Chiapas and to LMNP, and four are new records to Mexico. With the present study, the number of species for Chiapas, amounts to 131, placing the state in fourth place about myxomycetes richness in the country. The species and order composition of myxomycetes was different in each locality, establishing particular communities in each plant association. Arcyria cinerea, Hemitrichia serpula, and H.calyculata were the most abundant species and were shared in all localities. The species richness values are very similar in the different lakes, however, the abundance values were higher in San Rafael. The highest diversity corresponds to the Montebello area. Finally, the similarity value obtained showed that the comparative environments, present a particular and distinctive myxobiota, however, the similarity degree between lakes, had a geographical influence. Keywords: biodiversity, myxomycetes, protected natural areas P16. Are myxomycetes affected by urban centers? Preliminary evidence using traditional isolation methods Randall Valverdea, Pedro A. Rojasb, Carlos Rojasb aIndependent Researcher, Alajuela, Costa Rica. bEngineering Research Institute, University of Costa Rica, San Pedro de Montes de Oca, 11501- Costa Rica Most myxomycete field research takes place in natural areas and urban centers are often not considered for ecological studies. Using three radial schemes around urban centers in Costa Rica, a series of ground litter samples was collected and taken to the laboratory for moist chamber isolation. These samples came from the urban center and three points at 2.5 and 5 times the distance of such center and the edge of the respective urban area. Results showed that urban area size, topographical situation and sampling site characteristics were more important to explain results than landscape and climatic variables. Moreover, these results demonstrated that urban myxomycete monitoring could be useful in the context of climate change. Keywords: cities, landscape, urban ecology P17. Evaluating the moist chamber protocol for myxomycetes in three different forest types in Costa Rica Ricardo Moralesa, Randall Valverdeb, Carlos Rojasc a Facultad Multidisciplinaria de Occidente, Universidad de El Salvador, Santa Ana, El Salvador b Independent Researcher, Alajuela, Costa Rica. c Engineering Research Institute, University of Costa Rica, San Pedro de Montes de Oca, 11501- Costa Rica The extended region of Guanacaste in Costa Rica is represented by dry, moist and wet tropical forests. The last two are more typical of higher elevations than the former. In order to test the viability and usefulness of the moist chamber technique in a precipitation gradient, three areas were selected within Guanacaste. A series of 720 substrate samples represented by bark and ground litter were collected for this study, and during the moist chamber laboratory process, both environmental and microhabitat variables were determined. For the first, temperature, air humidity, light and barometric pressure of the laboratory were obtained; whereas humidity, temperature and pH were obtained at regular intervals inside the moist chambers. Results showed that the “typical” non-controlled laboratory conditions in Costa Rica´s central valley where close to 23.5°C, 74% humidity, 160 lux and 29.8 bars. The “typical” conditions of moist chambers were 20.7°C, 31.8% humidity and a pH around 6.3. With those conditions, samples from the driest forest yielded more species and showed more activity than those from the moist and wet forests. It is interesting to note the high laboratory humidity and the very mild temperature during the moist chamber process and the observation that cultures dehydrate slower than in laboratories with more controlled conditions. It is thought that those two factors along with the relative positioning of the cultures within the laboratory space may have an effect on results. In this manner, twin samples in different laboratories may yield different results. Similar evaluations on other laboratories would be useful to test the latter idea. Keywords: laboratory, moist chamber cultures, results, standardization Oral Contributions O1. The evolutionary history of the order Trichiales in a new multi-gene phylogenetic framework Iván García-Cunchillosa,b, Juan Carlos Zamorac, Martin Rybergd, Belén Estébanezb, Carlos Ladoa a Real Jardín Botánico, CSIC. Plaza de Murillo 2, E-28014 Madrid, Spain b Facultad de Ciencias, Universidad Autónoma de Madrid. Calle Darwin 2, Ciudad Universitaria de Cantoblanco, E-28049 Madrid, Spain c Museum of Evolution, Uppsala University. Norbyvägen 16, SE-752 36 Uppsala, Sweden d Department of Organismal Biology, Systematic Biology, Uppsala University. Norbyvägen 18 C, SE-752 36, Uppsala, Sweden The formation of spore-bearing fruiting bodies is the most noteworthy condition of Myxomycetes and what sets them apart from their closest ameboid relatives. The fruiting bodies and their features are the basis of the study of taxonomy in Myxomycetes. Based on these features several evolutionary hypotheses have been proposed for this group of organisms, resulting in distinct systematic classifications over time. The recent introduction of molecular tools in the systematics of Myxomycetes has brought to light totally unexpected phylogenetic relationships among the species. However, these pioneer phylogenetic studies lack an exhaustive taxa sampling and so is reflected in their conclusions. This is especially true for the order Trichiales. While this is the second richest group among the Myxomycetes, with around 200 currently accepted species, there is a really limited number of species for which molecular information is available. The aim of this study is to deep into the evolutionary relationships of the species of the order Trichiales, by increasing both the taxa sampling in the phylogeny and the number of analyzed genetic regions. A total of 60 species belonging to 12 of the 15 recognized genera in the order Trichiales are analyzed, covering the morphological variability of the order. In addition to the usually employed genetic regions for Myxomycetes, i.e. the nuclear 18S ribosomal DNA and the eukaryotic translation elongation factor 1 alpha 1, two different mitochondrial regions were also explored: the 12S ribosomal DNA (small subunit of the mitochondrial ribosome) and the cytochrome c oxidase I. Our results show major discrepancies between this multi-gene phylogeny and the current morphological-based classification. Some of the previously reported disagreements are herein also obtained, such as the position of the genus Dictydiaethalium within the Trichiales, questioning the consistency of the order Liceales. Additionally most of the represented genera are not recovered as monophyletic, which indicates a more complicated evolutionary history of the order Trichiales. Derived from these results, different morphological characters are re-evaluated in this new phylogenetic framework, focusing in the architecture of the capillitium- considering the dichotomy between net-forming capillitium or single tubules- as well as its ornamentation. Other features, as the spore ornamentation, presence and structure of the stalk and the characteristics of the peridium, are also discussed. In addition, ultrastructural features of the capillitium studied with Transmission Electron Microscopy (TEM) are also mapped in the phylogeny. The different derived ultrastructural types of capillitium are also discussed in this new phylogenetic framework. Deepen into the phylogenetic relationships among the species of Myxomycetes is challenging our understanding of their systematics. The further inclusion of molecular information in systematics will help us to solve that intricate puzzle which is the evolutionary history of the Myxomycetes. First author would like to acknowledge for the supporting PhD research grant (BES-2015-072763). This work is funded by the Spanish Government through the grant PGC2018-094660-B-I00 (MCIU/AEI/FEDER, UE). Key words: capillitium, myxomycetes, phylogeny, systematics, TEM, ultrastructure. O2. Combining morphology and molecular data to unravel the systematics of the Myxomycetes (Amoebozoa), with special emphasis on the order Physarales Joaquina María García-Martína, Juan Carlos Zamorab, Carlos Ladoa aDepartment of Mycology, Real Jardín Botánico-CSIC, Plaza de Murillo 2, 28014 Madrid, Spain. bMuseum of Evolution, Uppsala University, Norbyvägen 16, 752 36 Uppsala, Sweden. The Myxomycetes (Amoebozoa) is a diverse monophyletic group of amoeboid protists characterized by having a complex lifecycle that includes spore-bearing structures (sporophores), and free-living amoebae and flagellate cells. Given that these microscopic phases do not present obvious distinguishing characters, the taxonomy of Myxomycetes relies on sporophore morphology. Among others, the spore color and ornamentation, the features of the capillitium, stalk, peridium or columella, and the presence and type of lime deposits in the sporophores are considered taxonomically important characters. Nonetheless, some species present trait combinations that bridge the gap among different genera, even orders, making it difficult to establish their limits and phylogenetic affinities. In this work, we have generated the first and only comprehensive collection of transcriptomic data for Myxomycetes to test previous hypotheses on the relationships among the five orders currently recognized within this class. The monophyly of Myxomycetes and three of its orders has been proved, which confirms the validity of their respective synapomorphies to define high-level relationships. At a finer taxonomic level, we have focused our studies on the order Physarales, the largest group of Myxomycetes. By using a four-gene dataset and a greatly expanded taxa sampling, it has been confirmed that most genera are artificial and that morphological homoplasy is common, which makes morphology- based taxonomy challenging. Furthermore, even if several molecular synapomorphies have been identified for most clades in our multigene phylogeny, some internal relationships, especially in the family Physaraceae, remain unknown. Our results also indicate that the pre-molecular subdivision of Myxomycetes and, in particular, Physaraceae, is essentially flawed. Likewise, they show that transcriptomic analyses are a promising tool that along with other studies (e. g., ultrastructure), and an increased taxa sampling, will help us to disentangle the systematics of these elusive protists. This work was funded by the Spanish Government through a PhD research grant (BES2012-061641), awarded to the first author, and also by the Myxotropic Project (grant PGC2018-094660-B-I00 (MCIU/AEI/FEDER, UE). Keywords: myxomycetes, phylogeny, Physarales, systematics, transcriptomics. O3. How DNA metabarcoding changes our understanding of myxomycete ecology, diversity and distribution Oleg Shchepina,b, Yuri Novozhilova, Ilya Prikhodkoa, Nadezhda Fedorovaa,c, Vladimir Gmoshinskiyd, Martin Schnittlerb aLaboratory of Systematics and Geography of Fungi, Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Str. 2, St. Petersburg 197376, Russia bGeneral Botany and Plant Systematics, Institute of Botany and Landscape Ecology, University Greifswald, Soldmannstr. 15, Greifswald 17487, Germany cFaculty of Biology, Saint Petersburg State University, Universitetskaya Emb. 7/9, St. Petersburg 199034, Russia dFaculty of Biology, Lomonosov Moscow State University, Leninskie Gory Str. 1, Moscow 119991, Russia As the body of data produced by DNA metabarcoding studies (18S amplicon metagenomics) of myxomycete populations in different natural substrates keeps growing, new patterns of species diversity, as well as ecology and distribution of particular species, begin to emerge. Some aspects of these new patterns differ significantly from the picture created by the studies based on detection of fruit bodies in the field and in moist chamber cultures. We will present the results of the analysis of all myxomycete DNA metabarcoding datasets available to the moment, including our unpublished data, with an extended collection of reference 18S sequences used for taxonomic determinations, and discuss the impact of these findings on our understanding of myxomycete ecology and distribution. We acknowledge support from the Russian Foundation of Basic Research (18-04-01232 А), the program of the Komarov Botanical Insititute RAS “Biodiversity, ecology, structural and functional features of fungi and fungus-like protists” (АААА-А19-119020890079-6) and the German Research Council (DFG: SCHN1080/2-1, RTG 2010). Keywords: biogeography, DNA metabarcoding, molecular ecology, myxomycetes O4. Molecular phylogeny of Lepidoderma de Bary and its influence on inter- and infrageneric classification of Didymiaceae Ilya Prikhodkoa, Oleg Shchepina,c, Gabriel Morenob, Ángela López–Villalbab, Yuri Novozhilova, Martin Schnittlerc aLaboratory of Systematics and Geography of Fungi, Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Str. 2, St. Petersburg 197376, Russia bUnidad Docente de Botánica, Departamento de Ciencias de la Vida, Universidad de Alcalá, Alcalá de Henares 28805, Madrid, Spain cGeneral Botany and Plant Systematics, Institute of Botany and Landscape Ecology, University Greifswald, Soldmannstr. 15, Greifswald 17487, Germany At the moment, the genus Lepidoderma de Bary includes 15 species accepted in taxonomic database of Lado, which are characterized by cartilaginous or membranous peridium with lime scales on the outer layer. However, the taxonomic status of a number of morphological species, such as L. chailletii, L. carestianum, and L. aggregatum, has been a cause for debate over the past century. The aim of this work is to reconstruct a phylogeny of the genus Lepidoderma to clarify the composition of the genus and its relation to other genera of the Didymiaceae family. The partial sequences of 18S rRNA and COI genes were obtained from herbarium specimens of Lepidoderma tigrinum, L. chailletii, L. carestianum, L. peyerimhoffii and other species of the genus Lepidoderma and other genera of Didymiaceae. Lamproderma spp. were chosen as an outgroup. The 18S rRNA-based and two-gene phylogenetic trees showed that the two clades which include the majority of Lepidoderma spp. and number of Diderma spp. are sister groups, while the Didymium species occupy a more basal position. Several large monophyletic clades corresponding to morphological species are distinguished within the Lepidoderma. The results of the analysis showed that although some authors concluded that the morphology of L. chailletii and L. carestianum is similar, both species are independent and are located in distant branches within the genus. Moreover, sequences belonging to the L. chailletii morphological species are grouped into four clades with high statistical support, and the specimens belonging to these clades not only show different patterns of geographical distribution, but also differences in their macro- and micromorphology. It is important to note that the sequences of Diderma fallax fall into a clade that includes L. peyerimhoffii, L. nevadense, L. trevelyanii, and L. echinosporum, the four species similar to D. fallax as well in morphology. Finally, the analysis indicates that the type species of the genus Lepidoderma de Bary, L. tigrinum, is related to species of the genus Diderma: it forms a small branch with high support inside the «Diderma» clade. This indicates that both Lepidoderma and Diderma are paraphyletic genera, and large taxonomic rearrangements are needed to arrive to the natural system of Didymiaceae. We acknowledge support from the Russian Foundation of Basic Research (18-04-01232 А), the program of the Komarov Botanical Institute RAS “Biodiversity, ecology, structural and functional features of fungi and fungus-like protists” (АААА-А19-119020890079-6) and the German Research Council (DFG: SCHN1080/2-1, RTG 2010). Keywords: 18S rRNA, COI, Diderma, Didymiaceae, Lepidoderma, myxomycetes, molecular phylogeny, taxonomy O5. Information system on the DNA barcodes of myxomycetes Andrey Matveeva, Oleg Shchepinb,c, Vladimir Gmoshinskiya, Inna Zemlyanskayad, Anastasia Vlasenkoe, Nadezhda Fedorovaf, Ilya Prikhodkob, Yuri Novozhilovb, Martin Schnittlerc aFaculty of Biology, Lomonosov Moscow State University, Leninskie Gory Str. 1, Moscow 119991, Russia bLaboratory of Systematics and Geography of Fungi, Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Str. 2, St. Petersburg 197376, Russia cGeneral Botany and Plant Systematics, Institute of Botany and Landscape Ecology, Ernst Moritz Arndt University Greifswald, Soldmannstr. 15, Greifswald 17487, Germany dVolgograd State Medical University, Pavshikh Bortsov Square 1, Volgograd 400131, Russia eMain Siberian botanical garden of the Siberian branch of the Russian Academy of Sciences, Zolotodolinskaya Str. 101, Novosibirsk 630090, Russia fFaculty of Biology, Saint Petersburg State University, Universitetskaya Emb. 7/9, St. Petersburg 199034, Russia Species identification based on comparison of short nucleotide sequences (DNA barcodes) with reference sequences that have a reliable taxonomic annotation has become a routine for plants, metazoans, prokaryotes, fungi and many groups of protists within the last 15 years. This approach is successfully applied for identification of cultures, herbarium specimens, environmental DNA sequences etc. and is especially useful when morphological characters do not allow identification of a specimen to the desired taxonomic level. However, for myxomycetes DNA barcoding is at the initial stage of development: DNA barcodes with the suitable taxonomic resolution are found and primer combinations with reasonably broad specificity are developed, but taxonomic coverage of the available sequences in public databases is still unsatisfactorily small. Furthermore, many of these sequences have wrong taxonomic annotation and cannot be used as barcodes. To change this situation, several working groups united their efforts to create an information system of nucleotide sequences of myxomycetes that would contain quality-checked barcode sequences linked to herbarium specimens stored in large mycological herbaria of Russia and Germany. Sequences will be accompanied by metadata, such as light and SEM micrographs of sporocarps and spores, geographical data on the origin of the specimens and locality descriptions, which will allow anyone to check the correctness of taxonomic determination. Information system will be available via a web interface with the data stored on server of the Komarov Botanical Institute RAS. We acknowledge support from the Russian Foundation of Basic Research (18-04-01232 А) and the German Research Council (DFG: SCHN1080/2-1, RTG 2010). Keywords: DNA barcoding, information system, database, herbaria, myxomycetes, O6. Automated image analysis in determining the spore size of dark-spore myxomycetes Jan Woyzichovski a, Oleg Shchepin a, b, Nikki H.A. Dagamac a, Yuri K. Novozhilov b, Martin Schnittler a a General Botany and Plant Systematics, Institute of Botany and Landscape Ecology, University Greifswald, Soldmannstr. 15, Greifswald 17487, Germany b Laboratory of Systematics and Geography of Fungi, Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Str. 2, St. Petersburg 197376, Russia Spore size measurements are, in general, a tedious and time-consuming work that is flawed by human errors. These pitfalls often result in low sample sizes, non-reproducibility and inconsistent data, and low statistical power. We developed a new approach to measure the size of spores (myxomycetes, mosses, ferns ...) or pollen and other spherical propagules in a semi- automated method. With this method, we analyzed and compared over nine billion spores of Physarum albescens from different locations and putative biospecies. This method allows for achieving high sample sizes with large effect sizes that will positively influence the overall statistic power. At the same time, results are reproducible. A computer and an automated microscope do most of the analyzing steps. If the associated filters are adjusted to a representative sample, all the following samples will produce consistent results within and between the groups. Also, this method allows further analysis of each sample within the full spectrum of ImageJ tools on a level of single selected spores. This new approach consists of a pipeline that works with an automated brightfield microscope for image acquisitions and ImageJ- scripts for image decomposition. By using a newly developed sample preparation protocol, we could reduce noise effect (dirt particles, sporocarp fragments) and increase the spore count per image drastically. At the same time, we ease-up the image acquisition by focusing all spores on nearly one z-level by applying high-frequency vibration on the samples. First studies on Ph. albescens show leptokurtic distributions skewed towards larger spore size. These distributions are, in most cases, nearly identical between sporocarps of the same individual. We could reach margins of errors in a single-digit nm scale (1.3–4.6 nm) by an average spore size range from 10 to 12 μm. In addition, we could analyze rare events of macrospores with this method as well as disturbed spore formation on a few samples. We will use this method to investigate the reliability of one of the most often used traits in myxomycete determination: spore size. Keywords: spore size measurement, Ph. albescens, myxomycetes, computer vision O7. Current and future investigations on the antagonistic activity of Physarum species from Zea mays on plant pathogenic fungi causing mycotoxin contaminations and damping off diseases Adrian Gackb, Marc Lemmensb, Johann Ganglb, Myriam de Haana aMeise Botanic Garden, Research Department, Nieuwelaan 38, BE-1860 Meise, Belgium bUniversity of Natural Resources and Life Sciences, Vienna, Austria Some Myxomycete species are fungivorous e.g. Badhamia utricularis and some of them produce antifungal substances. Therefore, they hold the potential to be used in biocontrol as antagonists to fungal plant pathogens. Mycotoxigenic fungi contaminating feed and food with secondary metabolites bear considerable health risks for animals and humans and are an unsolved problem in agriculture. Damping off diseases caused by a variety of soil born fungi, attacking seedlings and small plantlets via the root system are one of the most difficult problems to be managed in nurseries and in the field. Both groups of fungi cause significant economic losses and alternative approaches to combat these plant pathogens are needed. In our laboratory wild isolates of several Physarum species, collected in agricultural experimental fields in Austria from maize plants (Zea mays), are tested on their antagonistic activity against plant pathogenic fungi causing mycotoxin contaminations and damping off diseases. Results of in vitro confrontation tests between P. gravidum against the mycelium and spores of mycotoxigenic fungi belonging to the genera Fusarium, Aspergillus, Penicillium and Alternaria as well as results for P. cinereum against a set of plant pathogenic damping off fungi belonging to the genera Phytophtora, Pythium, Rhizoctonia, Sclerotinia etc. are presented. A project - in pipeline - which aims to, elucidate the behavior of plasmodia in soil or soil like environments, establish the production of biomass of different Myxomycete life cycle stages in small scale, and investigate the in vivo activity of plasmodia in a real plant-pathogen system is presented and discussed. Keywords: corn, crops, pathogens, slimemolds O8. Integrated Mechanisms of cellular behavior in Physarum polycephalum: Towards a General Model System for Cognition Christina Oettmeiera, Hans-Günther Döbereinera aInstitut für Biophysik, Universität Bremen, Bremen, Germany Physarum polycephalum, probably the most prominent acellular slime mold, has garnered a lot of public interest in recent times. This is due to some fascinating research starting twenty years ago and concerning its apparent ‘intelligence’: The slime mold demonstrates abilities long thought to be restricted to neural organisms, among them learning, memory and the ability to solve problems. Not only is P. polycephalum capable of constructing networks optimized for transport. It has also been shown to solve mazes, connect multiple food sources via the mathematically shortest pathway, and tackle the traveling salesman problem. Furthermore, the slime mold makes decisions, evaluates food sources based on their nutrient conditions, and possesses a memory. These features are usually associated with life-forms which have a higher degree of information-processing sophistication, e.g. which possess brains or neuronal structures. Nonetheless, much of the slime mold’s behavior is similar to that of higher organisms. The underlying functions are not neuron- based, but are emergent phenomena, resulting from mechanochemical processes on the tubular network. However, an understanding of these underlying mechanisms and processes is still lacking. Since the structure of the cell and its dynamics are strongly interconnected, we investigated the ultrastructure and motility of P. polycephalum, which form the basis for the observed behavior. Large-scale patterns and other phenomena, which can be observed on the entire network, are based on locally occurring cellular and molecular processes. The interplay of these mechanistic interactions, and especially the resulting intracellular fluid flow, is hypothesized to constitute the information processing in P. polycephalum. Furthermore, and in light of the observed complex behavior, we wonder whether a detailed investigation of the unique cell biology, genetics, network analysis and metabolism of the slime mold could lead to an understanding emergent phenomena such as minimal cognition. Keywords: minimal cognition, fluidic information processing, Physarum O9. A morphological and molecular study of Myxomycetes collected from Zea mays Myriam de Haana, Johann Ganglb, Marc Lemmensb aMeise Botanic Garden, Research Department, Nieuwelaan 38, BE-1860 Meise, Belgium bUniversity of Natural Resources and Life Sciences, Vienna, Austria Maize (Zea mays L.) is one of the most important crops and staple food in our world. Plant diseases, like infections by mycotoxigenic fungi play an important role in the loss of crop yield. Because of global climate change species of these fungi that thrive in warmer climatic conditions are migrating into Northern areas, consequently there is continuous demand for new methods of eradication of these parasitic moulds. In the framework of an ongoing survey of mycotoxigenic fungi in a mist irrigated test field of different cultivars of maize, several taxa of myxomycetes have been detected. These are now being studied as potential antagonists against crop damaging and toxigenic pathogens. It is therefore imperative that these myxomycetes are correctly identified, well documented and that molecular voucher data is available for each of the taxa. Field samples of myxomycetes were collected during four consecutive years (2016-2019) from mid-August until the plants were ensiled around mid-October. In the same period of 2018 and 2019 substrates for moist chamber cultures were taken from different parts of the maize plants to ascertain if there were differences in species assemblages between ground leaf litter, aerial leaf litter, ears and silks. A morphological study of the sporocarps from a selection of the field collections and moist chamber cultures was performed. From each colony two sporocarps were isolated and separately use for DNA extraction, subsequently PCR was performed with primers to amplify about 1800 bp of the small subunit ribosomal RNA gene (SSU). We present the methods and results of this study. Keywords: corn, slimemolds, techniques O10. Impacts of natural disasters on microbial diversity: a case study of myxomycetes from tropical forests and grasslands in the Philippines Thomas Edison E. dela Cruza,b,c, Vanessa Joy C. Mapalob,c, Enrico M. Cabutajeb,c aDepartment of Biological Sciences, College of Science, University of Santo Tomas, España Blvd. 1008 Manila, Philippines bGraduate School, University of Santo Tomas, España Blvd. 1008 Manila, Philippines cFungal Biodiversity, Ecogenomics and Systematics (FBeS) Group, Research Center for the Natural and Applied Sciences, University of Santo Tomas, España Blvd. 1008 Manila, Philippines Natural disasters such as typhoons and volcanic eruptions negatively impact our biodiversity, particularly the flora and fauna. Can this negative impact be also true for microorganisms as exemplified by myxomycetes or slime molds? In this study, we assessed the occurrence and diversity of myxomycetes in forest habitats from two provinces, both situated in coastline areas and are frequently exposed to tropical cyclones. Leaf litter and twigs were collected eight months after a typhoon hit Aurora Province and a month after a typhoon hit Quezon Province for the preparation of moist chambers. Our results documented 63 species of myxomycetes belonging to 21 genera in the two forest habitats in both provinces. The inland forests had a higher species richness and diversity than the beach forests. Interestingly, a higher species richness and diversity was observed when sampling of substrata was conducted a month after a typhoon. We also prepared moist chambers from grass litter collected from grasslands in areas covered by “lahar flow” following volcanic eruptions of Taal (40 years ago), Pinatubo (26 years ago) and Mayon (11 years ago). A total of 40 species belonging to 11 genera were noted from the grasslands in Taal, Pinatubo and Mayon Volcanoes. Thirteen species were recorded common in all sites, with majority from the order Physarales. The assessment of species diversity showed that Taal had higher species diversity and richness than Mayon and Pinatubo. Our results clearly suggested that natural disturbances such as typhoons and volcanic eruptions could alter the diversity of myxomycetes, albeit not always negatively. A recovery among the microbial communities is expected. Keywords: biodiversity, disturbance, natural calamities, slime molds, tropical myxomycetes O11. Does myxobiota's response to burning differ with respect to fire intensity? Izabel Cristina Moreiraa,c, Felipe Viegas Arrudab,c, Werther Pereira Ramalhob,c, Solange Xavier- Santosa,c aLaboratory of Basic, Applied Mycology and Scientific Dissemination. Universidade Estadual de Goiás. Campus Anápolis de Ciências Exatas e Tecnológicas, Anápolis, Goiás, Brazil. bLaboratory of Biogeography and Aquatic Ecology – Bioecol. Universidade Estadual de Goiás. Campus Anápolis de Ciências Exatas e Tecnológicas, Anápolis, Goiás, Brazil. cGraduate Program in Natural Resources of Cerrado - Universidade Estadual de Goiás. Campus Anápolis de Ciências Exatas e Tecnológicas, Anápolis, Goiás, Brazil. Fire is a major cause of disturbance in savanna biomes. On the other hand, recent studies have demonstrated the importance of fire management in preventing environmental impacts, conserving species and maintaining phytophysiognomies. However, this practice is not yet common in Cerrado (Brazilian Savanna), and most research conducted in these areas is focused on plants, mammals and insects. This work aimed to analyze the impact of different types of managed burning on the Cerrado mixobiota. The study area corresponds to a fragment of cerrado sensu stricto, with about 107 ha, located in the territory of the quilombola Kalunga Community, municipality of Cavalcante, Goiás, Brazil. Within this area, four quadrants of 200x200m were delimited, three of which were subjected to different types of burning: fire against the wind (low intensity), fire in L (intensity intermediate), circular fire (high intensity) and one quadrant was not burned (control). In each quadrant, 4 to 20 random points were collected for substrate collection (leaflet), which were performed 6 and 12 months after burning. In the first sample, 16 samples were collected and in the second 80 samples, they were fractionated into three subsamples, which were incubated in humid chambers, and monitored over three months for the appearance of myxomycetes sporocarps and then verified the richness, composition and species diversity among the types of burning. Thirty-six specimens of myxomycetes belonging to 24 species, 11 genera, six families and four orders were obtained. Species richness varied among treatments, being higher in the control area, followed by low intensity, intermediate intensity and high intensity fire treatment. Species composition also differed between treatments, with more heterogeneous communities in wind control and treatment. The partition of beta diversity showed variation in species composition, attributed to differences in richness, which indicates selective loss of species with increasing fire intensity. Thus, we found that the intensity of the fire negatively influenced the Cerrado myxobiota, promoting a decrease in species richness, homogenization of communities and reduction of diversity through the selective loss of less resistant species. These data provide subsidies for eventual fire prevention and management programs in the Cerrado and, consequently, for the conservation of this biodiversity. We acknowledge the Goiás State Research Support Foundation (FAPEG) for the Masters scholarship to ICM and to Higher Education Personnel Improvement Coordination (CAPES), for the PhD scholarship to FVA and WPR. Also, the National Forest Fire Prevention and Fighting Center (PREvfogo/IBAMA) in the state of Goiás for the assistance and execution of the fires. To the Quilombola Kalunga community by the authorization for research in the area and for logistical support. Keywords: biodiversity conservation, controlled burning, fire impact, myxomycetes O12. Impact of forest fragmentation to the diversity and distribution of myxomycetes in Mt. Isarog, Camarines Sur, Philippines Maria Feliciana Benita M. Eloretaa,c and Thomas Edison E. dela Cruza,b aThe Graduate School, University of Santo Tomas, España Blvd. 1008 Manila, Philippines bFungal Biodiversity, Ecogenomics and Systematics Group, Research Center for the Natural and Applied Sciences, University of Santo Tomas, España Blvd. 1008 Manila, Philippines cPhilippine Science High School – Bicol Region Campus, Goa, Camarines Sur, Philippines Forest fragmentation alters the habitat area, thereby contributing to the loss of species diversity. While its negative effects on plants and animals are widely reported, little is known about their impacts on microbiota, specifically myxomycetes. This happens in spite of the critical roles microbes play in the ecosystems. In this study, we assessed the occurrence, distribution and diversity of myxomycetes in intact and fragmented forests within Mt. Isarog National Park in the Bicol Region, Philippines. Ground leaf litter (GL) and decaying twigs (TW) were collected from three sampling localities in Mt. Isarog. A total of 540 moist chamber cultures were prepared. The disturbance and forest land area of the collection sites were determined and correlated with the species diversity and distribution. Our results identified a total of 21 species of myxomycetes belonging to 9 genera: Arcyria (2 taxa), Comatricha (1 taxon), Cribraria (1 taxon), Diderma (2 taxa), Didymium (3 taxa), Hemitrichia (2 taxa), Perichaena (2 taxa), Physarum (6 taxa), and Stemonitis (2 taxa). Comparison of communities of myxomycetes showed that less disturbed forest habitats had higher species diversity than that of forest sites with man-made activities, e.g. eco- tourism. Our research study reports the possible impacts of man-made disturbances to the communities of myxomycetes. Keywords: forest disturbance, habitat loss, slime molds, tropical forests O13. Association between myxomycetes and the decay stage of coarse woody debris in an evergreen broadleaf forest in warm temperate Japan Yuichi Harakona, Kazunari Takahashib aHiroshima Municipal Hiroshima Secondary School, 1-14-1 Miirihigasi, Asakitaku, Hiroshima City, Hiroshima 731-0212, Japan bOkayama University of Science Senior High School, 1-1 Ridai-cho, Kitaku, Okayama City, Okayama 700-0005, Japan Myxomycetes inhabit coarse woody debris in varying stages of decay; however, their ecology in the dead wood of evergreen broadleaf trees is not well known. In this study, we examined the relationships between myxomycete species and the decay stage of wood from fallen trees in an evergreen broadleaf forest in Japan. Myxomycete species richness and abundance were calculated for eight stages of decay in fallen logs, according to the appearance and wood hardness of log portions. A total of 70 myxomycete species (including varieties) were found on the logs. Moderately decayed wood was the preferred habitat of myxomycetes (57 species; 81% of the total) and most species inhabited moist decayed wood. Analysis by nonmetric multidimensional scaling enabled the differentiation of myxomycete assemblages, with five groupings recognized across the progression of decay. Forty-two species preferred a particular decay stage, represented by the decay index (Fig.1). Physarum viride and Stemonitis splendens particularly preferred the less- decayed wood and Stemonitopsis typhina var. similis especially inhabited the well-decayed wood. Species from the order Physarales dominated the less-decayed wood, whereas Trichiales and Liceales species dominated the softer well-decayed wood. Myxomycetes diversity was high in and varied among logs with various stages of decay in a typical Japanese evergreen forest. Keywords: coarse woody debris, decay index, habitat preference, myxomycetes, species diversity Fig. 1. Myxomycetes habitat associating with decay stages and moisture content of decaying wood in an evergreen broadleaf forest. O14. Xylophilic myxomycetes: will the largest logs harbor the most, and the most rare, myxomycetes? Martin Schnittlera, Oleg Shchepina,b, Yuri K. Novozhilov b aGeneral Botany and Plant Systematics, Institute of Botany and Landscape Ecology, University Greifswald, Soldmannstr. 15, Greifswald 17487, Germany bLaboratory of Systematics and Geography of Fungi, Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Str. 2, St. Petersburg 197376, Russia Coarse woody debris is well known as a hot spot of fungal diversity, underlining the importance of pristine woodlands for conservation. But does this hold true for myxomycetes as well? These organisms share the dispersal biology (fruit bodies releasing airborne spores) with myxomycetes, but not the mode of nutrition: fungi take up dissolved organic compounds, myxomycetes are predators of other micro-organisms. We used several data sets from pristine forest throughout the northern hemisphere (Germany: Bavarian Forest; Russia: Sikhote-Aline reserve, Interior Kamchatka, Northern Caucasus) to answer these questions. In these surveys, a log was systematically surveyed for all fruiting myxomycetes and its length and maximum diameter was recorded. We found indeed a trend of increasing diversity with increasing diameter of the log – up to 15 species were found on well-decayed coniferous logs. However, in a given survey the rarest xylophilous species were not necessarily found on the largest logs, although certainly a number of species seem to require a minimum diameter of logs for successful fruiting. A good example seem to be the species of Siphoptychi