De novo organogenesis and plant regeneration in Pongamia pinnata, oil producing tree legume

Abstract

Role of Thidiazuron (TDZ) in inducing adventitious organogenesis in Pongamia was studied. TDZ at different concentrations (0, 0.45, 2.27, 4.54, 6.71, 9.08, 11.35, 13.12 and 22.71 lM) were used for induction of caulogenic bud formation in deembryonated cotyledon explants. Each cotyledon was cut into three segments and identified as proximal, middle and distal. Duration of TDZ exposure, influence of the segment and orientation of the explant were studied. TDZ at 11.35 lM concentration was optimum for the induction of shoots and rapid elongation. Shoots induced at higher concentration elongated after several passages in growth regulator free medium, thereby extending the period of differentiation. Exposure of the explant for 20 days yielded more number of buds than 10 days. Proximal segment of the cotyledon was more responsive. Contact of abaxial surface in the medium was more effective and generated more buds than the adaxial side. Buds differentiated and elongated on transfer to MS basal medium for 8-12 passages of 15 days each. Rooting and elongation of shoots was achieved in charcoal supplemented half-strength MS medium. Rooted plantlets survived on transfer to sand soil mixture. The plants were hardened and transferred to green house. This is the first report on in vitro regeneration of Pongamia pinnata via adventitious organogenesis using TDZ. This protocol may find application in studies in genetic transformation, isolation of somaclonal variants and in induction of mutants. It also provides a system to study the inhibitory role of TDZ on shoot differentiation.

Expansion of a direct shoot organogenesis system in peanut (Arachis hypogaea L.) to include US cultivars

“…Other studies have provided data to explain the highly prolific nature of the proximal region of cotyledon explants. Sujatha et al (2008), using a direct shoot organogenesis protocol, tested three cotyledon segment types (proximal, middle, and distal) of Pongamia pinnata, a tree legume. This study concluded that the proximal cotyledon section, followed by the middle and distal sections, was most responsive in terms of producing shoot buds.…”

Direct OrgaNogenesis from Cotyledons in Cultivars of Citrus clementina Hort. Ex Tan

“…Regeneration from cotyledon explants has been reported in several taxa [21][22][23][24]36,37] but it has been recorded in only a few species belonging to Citrus genus: adventive embryos formation in Citrus reticulata Blanco (Nagpur mandarin) and C. jambhiri Lush. (Rough lemon) [5], indirect somatic embryogenesis in C. reticulata "Local Sangtra" [38] and indirect shoot regeneration in C. grandis (L.) Osbeck (pummelo) [32,39].…”

“…Organogenesis from cotyledons was successfully obtained in Pongamia pinnata (L.) [21], Glicine max (L.) Merril [22], Dalbergia sissoo Roxb. [23], Capsicum annum L. [24] and Citrullus lanatus (Thunb.)…”

Tree legumes as feedstock for sustainable biofuel production: Opportunities and challenges

“…3A). Complete regeneration through organogenesis was reported from de-embryonated cotyledon explants (Sujatha et al, 2008;B. Biswas, unpublished data).…”