Somatic embryogenesis and plant regeneration from transverse thin cell layers of adult peach palm (Bactris gasipaes) lateral offshoots

Abstract

In this work, we report a successful protocol to obtain in vitro peachpalm (Bactris gasipaes Kunth) “Diamantes 10” plants through somaticembryogenesis from transverse thin cell layer (TCL) explants, dissected fromthree sections (basal, medial, and apical) of lateral offshoots of adult plantscultured on different concentrations of 4-amino-3,5,6-trichloropicolonic acid(picloram). After swelling and development of primary callus in all treatments,without any strong effect of explant origin or picloram concentration, itwas possible to observe the formation of embryogenic structures and theexact point from where they developed. Browning was also observed andcorrelated to the induction treatments, although it was not an impairmentfor the production of embryogenic structures. Subsequent maturation andconversion of somatic embryos into plantlets allowed their acclimatization17 months after culture initiation (ACI), which was quicker than previousreports with juvenile tissues (from embryos or seed-germinated plantlets). Tothe best of our knowledge, this is the first report on peach palm regenerationthrough somatic embryogenesis from TCL explants from adult plants andcould constitute, after fine-tuning the acclimatization stage, a tool for massclonal propagation of elite genotypes of this open-pollinated crop, as wellas for the establishment of conservation strategies of in situ gene bank plantaccessions endangered due to aging and other threats.