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 peach palm (Bactris gasipaes Kunth) “Diamantes 10” plants through somatic embryogenesis from transverse thin cell layer (TCL) explants, dissected from three sections (basal, medial, and apical) of lateral offshoots of adult plants cultured 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, it was possible to observe the formation of embryogenic structures and the exact point from where they developed. Browning was also observed and correlated to the induction treatments, although it was not an impairment for the production of embryogenic structures. Subsequent maturation and conversion of somatic embryos into plantlets allowed their acclimatization 17 months after culture initiation (ACI), which was quicker than previous reports with juvenile tissues (from embryos or seed-germinated plantlets). To the best of our knowledge, this is the first report on peach palm regeneration through somatic embryogenesis from TCL explants from adult plants and could constitute, after fine-tuning the acclimatization stage, a tool for mass clonal propagation of elite genotypes of this open-pollinated crop, as well as for the establishment of conservation strategies of in situ gene bank plant accessions endangered due to aging and other threats.

Thin Cell Layer Tissue Culture Technology with Emphasis on Tree Species

“…tTCL 0.4-0.5 mm [9] Malus spp. tTCL 0.1-0.3 mm [16,17] Jatropha curcas L. tTCL 0.8-1.0 mm [18] Passiflora edulis Sims tTCL 0.5 mm thick [20] Camellia sinensis L. lTCL 0.5 mm [26] Elaeis guineensis × Elaeis oleifera tTCL 1 mm thick [2] Guadua chacoensis (Rojas) Londoño and P.M. tTCL 0.5-1.0 mm [34] Actinidia chinensis tTCL 0.5-1.0 mm thick [35] Bactris gasipaes Kunth tTCL 0.3 mm [36] Bactris gasipaes Kunth tTCL 7.0-9.0 mm [37]…”

“…Therefore, the results obtained by these authors serve as a basis for establishing plant regeneration protocols in other bamboo species for commercial reforestation purposes. In Bactris gasipaes, Campos-Boza et al [36] reported that LCTs promoted the induction of somatic embryogenesis by 97%. Moreover, this method favored the induction of vigorous somatic embryos.…”

Understanding the Technical-Scientific Gaps of Underutilized Tropical Species: The Case of Bactris gasipaes Kunth

“…In a recent study, Campos-Boza et al [ 145 ] applied protocols using shoots while also testing different concentrations of picloram and different positions of TCL meristems in the culture medium. The study concluded that there were no significant differences in the picloram concentrations and meristem position in embryonic competence acquisition, contrasting observations by Steinmacher et al [ 141 ].…”

“…These results may be related to the phenological phase of the tissue. Other experiments used plant material from a juvenile or immature phase (seedlings, immature inflorescences, zygotic embryos), unlike the shoots used by Campos-Boza et al [ 145 ]. The material provided from shoots showed less contamination and browning in comparison with cryopreserved zygotic embryos and TCLs from seedlings.…”

An Overview: Somatic Embryogenesis Through Thin Cell Layer (TCL) Technique

“…Also, on Table. I, the DSE pathway was established in Cymbidium aloifolium [35], Lilium ledebourii [33], Agave fourcroydes [25], Dendrobium nobile [35], and the ISE pathway was established in Dendrobium candidum [36], Saccharum species hybrids [31], Bactris gasipaes [37], and Lilium longiflorum [23].…”