Molecular variability among Macrophomina phaseolina isolates causing dry root rot of cluster bean using RAPD technique

Aim: Molecular characterization of Macrophomina phaseolina isolates collected from different cluster bean growing areas of Rajasthan and adjoining state. Methodology:Genetic variation among ten isolates of Macrophomina phaseolina were examined for Random Amplified Polymorphic DNA (RAPD) genetic marker with ten decamer primers of OPB and OPG series. All the 76 bands were found to be polymorphic and the level of polymorphism was 100 per cent. Genetic similarity estimated by Jaccard's coefficient based on RAPD banding patterns was used for cluster analysis to ascertain the genetic relationship in the form of dendrogram. Results:The range of genetic similarity among Macrophomina phaseolina isolates was found between 0.22 (MpDLI and Mp-CUR) to 0.63 (Mp-HMG and Mp-SNGR). The average genetic similarity coefficient observed was 0.46. The clustering analysis separated all the ten isolates in three major groups. Group I included (Mp-BKN, Mp-CUR, Mp-SGNR, Mp-HMG, Mp-JJN, Mp-SWM, Mp-AWR) whereas Group II consisted of two isolates (Mp-HSR and Mp-NNL), Group III (Mp-DLI). Interpretation:With the help of RAPD techniques, useful information for characterization of fungal pathogens can be generated when the quantity of available DNAis low.