IN VITRO REGENERATION OF Bambusa nutans WALL. VIA SOMATIC EMBRYOGENESIS AND EVALUATION OF GENETIC FIDELITY USING ISSR MARKERS

An efficient and rapid in vitro plant regeneration system was successfully developed through somatic embryogenesis for Bambusa nutans Wall, an important commercial species of Thailand and India, commonly used in pulp and paper industries. Present investigations were conducted to study the effects of different plant growth regulators (PGRs) viz; NAA, IAA, IBA, 2,4-D, BAP, TDZ, GA3, ABA and PEG on percentage of embryogenic callus induction, maturation and germination. Initially, to obtain nodal shoot segment as an explant for induction of embryogenic callus, multiple shoots were induced from nodal shoot segments of young branches of mature field grown culm on MS liquid medium supplemented with NAA 0.25 mg/L+ BAP 5.0 mg/L. Shoots were multiplied by subculturing on fresh MS liquid medium supplemented with NAA 0.25 mg/L+ TDZ 0.25 mg/L at 2 weeks intervals. Subsequently, Embryogenic callus was induced from the nodal shoot segments obtained from shoot multiplication cultures (fifth passage) of mature clumps on MS agar gelled medium containing 2,4-D (2.0 mg/L ) under dark condition. Addition of 10% coconut water (CW) in MS medium along with 2,4-D (2.0 mg/L ) was found best treatment for multiplication of embryogenic callus. MS medium supplemented with NAA (1.0 mg/L) and TDZ (0.5 mg/L) was found significantly (p≤0.05) to be best combination for high (74.26%) percentage of somatic embryo induction compared to other PGRs. Maturation of somatic embryo was highly (86.04%) achieved on hormone free MS medium with minimum abnormality. Subsequently, highest (41.93%) rate of somatic embryo germination was achieved on MS medium containing NAA (1.0 mg/L) and GA3 (1.0 mg/L). Plantlet thus produced acclimatized easily under greenhouse conditions. Genetic fidelity of plants regenerated through somatic embryogenesis was assessed using10 ISSR primers, revealed a high level of genetic stability.