Molecular Assessment of Genetic Fidelity of Micropropagated Banana (Musa acuminata L.) using SSR markers

Characterization of genetic fidelity of micropropagated banana plants using SSR markers is the first report. An efficient and reproducible micropropagation protocol was developed for mass multiplication of the elite banana (Musa acuminata L.) cultivar Grand Naine (AAA) through axillary shoot proliferation. Young suckers (3-13 cm diameter) were treated with bavistin (0.1%) for 45 minutes and HgCl2 (0.1%) for 10 minutes to eliminate fungal and bacterial contamination, respectively. Suckers having diameter 9-11 cm gave maximum number of shoots per explant (8.33). Shoot tips excised from young suckers were cultured on modified MS medium supplemented with 5 mgl(-1) BAP for establishing the shoot cultures. Addition of an antibiotic, cefotaxime (500 mgl(-1)) to the culture medium reduced endogenous bacterial contamination. Shoot multiplication was achieved on BMM (Banana Multiplication Medium). In vitro multiplied shoots showed maximum root induction (89.96%) on BMM + 1 mgl(-1) IBA. Hardening acclimatized the plantlets which were transferred to polythene bags containing field soil and farmyard manure (FYM) in 1:1 ratio. The plants were maintained in the glasshouse for 3-4 months till these attained a height of I foot. Molecular characterization was done by isolating DNA from mother plant and micropropagated banana plants using CTAB method. A total of 25 PCR-based primers viz., microsatellites of Mb-1 series were surveyed for the detection of polymorphism among different plants. None of the primers showed polymorphism among the various micropropagated plants and the mother plant.