An Efficient Protocol for in vitro Regeneration of Banana var. Nanjangudu rasabale (Musa spp. AAB)

Abstract

Banana belonging to the family Musaceae and section Eumusa, and the cultivated edible types are mainly triploid in nature with basic chromosome number 11 (Salaria, 2004).Banana is the world’s most widely known and distributed fruit, eaten raw, cooked or processed. In general, bananas are good source of carbohydrates, proteins, vitamins and minerals. It is treated as symbol of prosperity and fertility owing to its greater socio-economic significance and utility, it is referred to as kalpatharu and kalpavriksh (Singh, 2009). Banana cultivar Nanjanagudu rasabale (Musa spp. AAB) classified under silk subgroup has been given Geographical Indication (GI) protectionin 2005 under the Goods (Registration and Protection) Act, 1999 by Government of India for its distinguished aroma, flavour and taste. Nanjanagudu rasabale has been grown in and around Mysuru and Chamarajanagar districts of Karnataka and drives huge demand throughout the country. This variety is very difficult to get and becoming rarer by the day. Very few shops sell this varietyin Mysuru at an exorbitant price, but it is worth buying it. Banana variety Nanjanagudu rasabale has been found growing in parts of Mysuru district, known for its unique aroma, flavour, taste and shelf life but unfortunately deemed as an endangered variety. Having given GI protection hope for bringing this variety back to field by producing disease free tissue culture plants demanded development of an efficient protocol for in vitro regeneration. In the present investigation, both citric acid and ascorbic acid found effective in inhibiting browning of shoot tip explant due to phenolic compounds. Each of the chemical sterilants was effective in reducing microbial contamination when they were used in sequence one after the other.MS media supplemented with BAP at 3.0 mg/l took least number of days for shoot regeneration and favoured better shoot production with maximum number of leaves per shoot and shoot length. Addition of 25mg/l adenine sulphate and 2-3 ml of Aonla juice proliferated maximum number of shoots during multiplication. MS media at half strength provided with activated charcoal and IBA at 2 mg/l was effective in producing better roots from in vitro grown shoots. K e y w o r d s