Selection and characterization of gamma ray induced Bunchy Top Virus resistant mutants in banana cv. Lakatan (Musa sp. AA)

Gamma irradiation coupled with in vitro technology was used to develop Banana Bunchy Top Virus (BBTV) resistance in banana cv. Lakatan (Musa sp. AA). A total of 6,012 plants regenerated from irradiated shoot cultures were subjected to BBTV artificial inoculation using the aphid vector (Pentalonia nigronervosa Coq.) in green house. From these, 64 mutant plants with varying degrees of resistance/tolerance reaction to BBTV were selected after 30 months of evaluation. The resistant mutant plants were induced from 5 to 30 Gy gamma rays. Twenty six plants showed no BBTV symptoms in both irradiated and first generation sucker plants (rated resistant). The other 38 plants showed limited BBTV symptoms (rated intermediate resistant). Yield and agronomic traits of some resistant plants were comparable to non-irradiated tissue culture plants. Shorter plant stature was also generated in some BBTV resistant mutant plants. First generation suckers from resistant plants were evaluated for second cycle stability of the resistance trait. (author)