Comparison of micropropagation efficacy among different grape hybrids with special reference to Shweta Seedless

Abstract

Among the six grape varieties Black Champa, Arka Neelamani, Anab-e-Shahi, Shweta Seedless and Arka Krishna taken up in the study Black Champa variety of grape responded the best to in vitro culture while Arka Krishna was the least responsive on MS medium supplemented with various levels of growth regulators; IBA and NAA. IBA supplemented to medium was found to be better for in vitro culture establishment compared to the one supplemented with NAA. Rooting, sprouting and growth response obtained varied with the variety. All the six varieties showed better rooting response in MS medium supplemented with IBA compared to those cultured on MS medium supplemented with NAA. Black Champa, Arka Neelamani, Anab-e-Shahi, Shweta Seedless and Thompson Seedless gave higher root number and root length at higher concentrations of IBA tried (3 mM) compared to the lower concentrations. Arka Krishna showed the lowest root number and root length, which was observed at a lower concentration of IBA. All the varieties except Arka Krishna showed the maximum root weight at higher concentrations of IBA. Black Champa variety showed maximum rooting, sprouting and growth response at higher level of IBA (3 mM). In general it gave the highest root number, root length, sprout height, root weight, node number and leaf number when compared to the other varieties. This shows that in vitro culture can be taken up successfully for Black Champa variety of grapes. It was found that in Thompson Seedless higher IBA levels favoured rooting response, growth response and sprout weight while lower IBA concentration favoured better sprout height. Arka Neelamani resembled its paternal parent Thompson Seedless in rooting requirements (root number, root length and root weight) while shooting was better at a lower concentration of IBA. Anab-e-Shahi showed variable response at different levels of IBA. It gave the highest root number, root length, and sprouts height and root weight at higher concentration of IBA while the sprout weight was observed to be maximum at lower level of IBA. The growth variables leaf number and node number were maximum at higher levels of IBA. It was observed that Shweta Seedless variety resembled its parent Anab-e-Shahi in its rooting response and sprout height; while on the other hand, for higher sprout weight it needed a higher concentration of IBA than Anab-e-Shahi. Further, it was observed that in Shweta Seedless and its parents (Anab-e-Shahi and Thompson Seedless), the growth response (leaf number, node number) and sprout height were better on full-strength MS media compared to half MS medium. On the other hand the rooting response and sprout height was better on full MS medium. In vitro culture of Shweta Seedless single nodal cuttings on a combined 2 mM BA and 2 mM IBA supplemented media gave the best shoot and root system without any callusing. Nearly 80 per cent survival was obtained when in vitro derived plantlets of representative samples transplanted into polybags using the closed sachet method.