Keywords: Banana, Embryogenic calli, Embyrogenic cell suspension, Multiple shoot clump, Somatic embryogenesis
An efficient and rapid regeneration system is indispensable for germplasm conservation and valuable trait incorporation through genetic engineering. The present study was aimed to investigate regeneration potential of Musa sp. cv. Somrani monthan (ABB) via somatic embryogenesis. Meristematic shoot tips were used as explant and cultured on MS medium supplemented with 6-BAP (50 and 100 µM) and IAA (1 µM) for scalp (cauliflower like compact buds) induction. The highest percentage (~ 60%) of homogenous differentiation of shoot tip explants into scalp was observed in MS medium supplemented with 100 µM of 6-BAP and 1 µM of IAA after 6 months of culture. The scalps were sub-cultured on MS medium supplemented with different compositions of 2, 4-D (1, 2, 3, 4, 5 and 10 µM) and zeatin (1 and 2 µM) for embryogenic calli induction. The highest frequency (97%) of embryogenic calli induction was recorded in MS medium supplemented with 5 µM 2, 4-D and 1 µM zeatin after 6 weeks of culture. The histological and morphological studies suggest that, callus possessed high competence for embryogenesis and could be induced to form somatic embryos. Embryogenic cell suspension (ECS) was successfully established by culturing these embryonic calli in liquid medium. About 70% of the mature somatic embryos germinated and converted to plantlets with a regeneration capacity of 8.5 × 103. After the gradual acclimatization and hardening, the plants were transferred to nursery with 82% of survival rate. Here we report a successful regeneration system for an elite Indian Musa cv. Somrani monthan via somatic embryogenesis. The embryogenic callus and ECS are ideal explants for mass clonal propagation, germplasm conservation and genetic transformation for future research.
Authors acknowledge Dr. Anuradha Agrawal, National Bureau of Plant Genetic Resources, New Delhi, India for providing the in vitro shoot cultures of Musa variety. Somrani monthan. Lab training to AR by Dr. Leela Sahijram, IIHR, Bangalore and by Dr. V. M. Kulkarni, BARC, Mumbai is kindly acknowledged. Financial assistance from UGC, CAS, UGC-RNW, DST-FIST, DST-PURSE is gratefully acknowledged. Fellowships to AR from UGC and SS from DBT project grant are also acknowledged.