In Vitro Propagation and Somatic Embryogenesis in Phalsa

Abstract

Phalsa[Grewia asiatica (L.) Tiliaceae] is an exotic fruit with good nutraceutical values. It cannot be grown in temperate climates with severe winters. Therefore, genetic improvement of phalsa for cold tolerance is essential. In order to apply biotechnology through genetic transformation to enhance cold hardiness, a reliable and rapid micropropagation system is needed. Thus, developing the most dependable micropropagation protocols for phalsa was the primary goal of this research. Phalsa explants prepared from different tissues, including leaf, nodes, internode, and zygotic embryos, were collected from mature trees growing in the specialty plants house, cultured on MS medium supplemented with various cytokinins alone or along with auxins and incubated under a 10-hour photoperiod at ambient temperature. In vitro propagation of phalsa tissues through both organogenesis and somatic embryogenesis was achieved. Of these, single shoots were developed from nodal explants as a result of budbreak on MS medium supplemented with BAP, kinetin, and zeatin separately. Somatic embryos were developed from the zygotic embryos when cultured on MS medium with 0.023 μm BA + 0.022 μm zeatin, for 2 weeks following a pulse treatment on NN medium supplemented with 5% sucrose, 0.11 μm BAP, 0.22 μm 2,4-D, and 29.20 μm L-glutamine. Somatic embryogenesis was also observed on modified basal medium supplemented with 13% sucrose, 58.40 μm L-glutamine, and 1.75 μm IAA. Enormous callusing was a major problem for in vitro studies with this species, irrespective of media composition. Further studies for multiple shoot development and higher frequency of SE induction are under way.