Factors affecting in vitro shoot-tip culture of banana

Abstract

Various factors affecting in vitro shoot-tip culture of banana were examined to standardize the suitable culture media, as well as the culture environment. Three local cultivars identified for experiments, viz., 'Amritsagar' (AAA), 'Bharatmoni' (AAA) and 'Kanaibasi' (AA), have high potential in terms of plant growth, yield and fruit quality in commercial cultivation. Shoot tips from 3-month-old suckers of these cultivars were selected as explants source and were cultured on modified MS medium containing different concentrations and combinations of auxins and cytokinins, along with some other supplements, and incubated under different temperatures. Highest frequency of explant survival, regrowth and highest multiplication of shoots was observed on modified MS medium with 5 mg L-1 6-benzylaminopurine, 1 mg L-1 indole-3-acetic acid (IAA), 2 g L-1 activated charcoal and 50 mg L-1 casein hydrolysate, at a temperature of 27°C. About 20 shoots per plant could be achieved in this medium within 6-8 weeks of culture. Healthy roots were induced by subculturing shoots on half-strength MS medium supplemented with 2 mg L-1 of indole-3-butyric acid within 15 days of incubation. Regenerated plantlets were transferred to soil after hardening. After attaining the average height of 25 cm, the plants were transferred in the field. The plants showed vigorous growth in terms of total leaves per plant, total leaf area, pseudostem circumference and height of the plants. Preliminary results show that the quality and the productivity of the in vitro-derived plants are superior in comparison to conventional sucker-derived plants.