Genetic differentiation of Bipolaris spp. based on Random Amplified Polymorphic DNA markers.

摘要

A total of 17 Indian isolates of Bipolaris spp., which included 12 isolates of B. sorokiniana [Cochliobolus sativus], 2 isolates each of B. specifera [C. spicifer] and B. tetramera [C. spicifer] and one isolate of B. maydis [C. heterostrophus], were taken up for identification of genetic markers and to provide a protocol for the identification and characterization of isolates using the RAPD technique. The genomic DNA was compared using 40 random decamer primers that generated 554 bands; out of which 549 were polymorphic products. Genetic similarities of RAPD profiles were estimated based on the Jaccard's coefficient. The similarity index values ranged from 0.474 to 0.906 indicating the presence of a wide range of genetic diversity. These similarity coefficients were subjected to unweighted pair group method on arithmetic averages using paired matrix values. The dendrogram generated consisted of 2 major clusters, one having all isolates of B. sorokiniana and another cluster having isolates of B. specifera, B. tetramera and B. maydis, which were further distinguishable from each other by falling into different subgroups. The banding pattern of the different isolates can also be used as reference for further comparisons.