IN VITRO REGENERATION OF LITCHI (Litchi chinensis SONN.) THROUGH SHOOT BUD CULTURE

Abstract

Attempts were made to develop protocol for in vitro regeneration of litchi through axillary shoot bud cultures. The problem of microbial contamination, phenolic exudation and media browning was controlled up to some extend by pretreatment and rapid subculturing. A high frequency (51 %) shoot induction and differentiation was obtained in litchi Gola variety axillary explants on MS medium containing GA3 and BAP (1 mg/l), Kin (2 mg/l). In vitro raised shoots better proliferated in medium containing 2 mg/l BAP. BAP had positive effect on multiplication and growth of shoots but higher concentration than 2 mg/l reduced growth. Maximum rooting frequency (66.67%) with healthier roots was obtained in shoots cultured on full strength MS medium supplemented with IBA (2 mg/l). Plants with well-developed roots were transferred to soil with survival frequency of 57%. A combination of BAP and GA3 (1 mg/l), KIN (2 mg/l) was effective in establishment of cultures. While BAP (2 mg/l) and KIN (3 mg/l) was good for better flourishing in vitro raised shoots. 6-benzylaminepurine had positive effect on multiplication and growth of in vitro shoots but concentration exceeding 2 mg/l decreased growth. Full strength MS medium containing 2 mg/l IBA under dark condition promoted rooting in in vitro raised shoots. The protocol established could prove advantageous to the horticulturists and the industry for developing trees true to the parental type.