Somatic Embryogenesis and Plant Regeneration in Diploid Banana Cultivars (Musa acuminata cv. Chingan and Musa acuminata cv. njalipoovan) from Kerala

Plant regeneration by somatic embryogenesis was attempted with diploid banana cultivars Musa acuminata cv. Chingan (AA) and Musa acuminata cv. Njalipoovan (AB). In vitro plants grown on solid MS medium supplemented with BA (4.4–17.6 μM) and TDZ (0.45–9 μM) were used as explant source. The basal meristem including 3–4 leaf primordial and excised apices were inoculated on MS medium supplemented with 2,4-D (0.225–9 μM) and BA (0.044–8.8 μM) for callus induction. Pale yellow embryogenic callus initiated after three weeks of inoculation and subsequent subculture were done in the same medium to enhance callus proliferation. Maximum callus proliferation was observed in 2,4-D (4.5 μM) along with BA (2.2 μM). Embryogenic calli were isolated and transferred to 100 ml erlenmeyer flask with 20 ml of liquid MS medium with zeatin (0.46–4.56 μM) and malt extract (100 mg/l) or malt extract and ascorbic acid (0.01–0.5 mg/l). The culture medium was refreshed every third week, embryogenic complexes and compact structures were removed. Small embryo-like structures and embryogenic calli were transferred to fresh medium. After 4–5 subculture the embryos were isolated and inoculated on petridish containing MS basal medium. Leaf and root initials were developed after 2–3 weeks. These were then transferred to same medium in culture bottles. After 3 weeks, plants of 4–5 cm height were transferred to vermiculate with 100 per cent survival rate.