Studies On Genetic Transformation Of Banana For Imparting Banana Bunchy Top Virus Resistance

Abstract

Banana bunchy top disease (BBTD) is caused by banana bunchy top virus newline(BBTV), which is transmitted by banana black aphid (Pentalonia nigronervosa newlineCoquerel). Among many diseases, BBTD is one of the most threatening diseases in newlinebanana cultivation and causes significant reduction in yield and quality of the crop. With newlineview to develop bunchy top disease resistant cultivars, an attempt was made to impart newlineresistance against banana bunchy top virus through RNAi approach via genetic newlinetransformation. newlineIn this present study, plant regeneration based somatic embryogenesis protocols newlinewere standardized for popular banana cvs. Rasthali (Silk sub-group, AAB), Grand Naine newline(Cavendish sub-group, AAA) and Hill Banana (Pome sub-group, AAB). During the newlinecourse of study, morphologically different types of calli were observed. White translucent newlinepro-embryogenic mass of calli derived from immature male inflorescence was found to newlinebe embryogenic and used for establishment of embryogenic cell suspension (ECS) newlinecultures. Regeneration potential of ECS was assessed and different stages of embryo viz., newlineglobular, scutellum, and coleoptillar stages were observed under scanning electron newlinemicroscope. Genetic fidelity testing through ISSR marker analysis showed that somatic newlineembryo derived banana plants were genetically identical to the sucker derived banana newlineplants. newlineField performance of plants of cv. Rasthali and cv. Grand Naine derived through newlinesomatic embryogenesis was studied. It was found that the yield and quality attributes are newlinecomparable to that of tissue culture plant materials or conventional suckers in both the newlinecultivars. Genetic transformation of banana cultivars was carried out to engineer newlineresistance against BBTV. Two RNAi constructs, pBOM-001 targeting MP gene and newlinepBBTV targeting three BBTV genes (Rep, CP and MP) were separately mobilized into newlineAgrobacterium strain AGL1 and used for banana transformation. Sixty-five putative newlinetransgenic Rasthali plants transformed with pBOM-001 construct were generated. newlinePCR analysis confirmed the presence of the