Adventitious Shoot Regeneration from Apple Leaf Explants and Rapd Analysis of Regenerants

The present studies were aimed to develop a reliable technique to obtain high frequency regeneration in clonal apple rootstock Malling 7 through leaves as explants taken from in vitro grown shoots and to assess the genetic variability among regenerants using RAPD technique. Regeneration was obtained on MS medium with different combinations of BA, NAA and IAA in both light and dark incubation. Maximum regeneration (56%) was obtained on 5.0 mg/l BA and 1.0 mg/l NAA with highest number of shoots per regenerating explant (9.0) on incubation in light. Regenerated shoots were multiplied, rooted and hardened. DNA was isolated from mother plant of M7 and 13 regenerants produced. They were subjected to RAPD-PCR analysis using 80 decamer primers initially. Out of these, 26 primers yielded consistent and reliable differences during repeated analysis. Total 134 scorable bands were observed with 58.2% polymorphism. Similarity coefficient values were higher among regenerants than between regenerants and the mother plant. The dendrogram obtained from all 14 samples revealed four clusters and one separated regenerant which did not cluster with others. Hence, reported somaclonal variations could be exploited in various quantitative and qualitative traits. Therefore, further investigations are necessary to achieve the goals of apple crop improvement programmes.