Comparative analysis of RAPD and ISSR marker assays for detecting genetic polymorphism in Tilletia indica

Karnal bunt of wheat, caused by Tilletia indica Mitra is an important disease prevalent in several countries. The pathogen due to its heterothallic nature shows high variability. In the present study, genetic relationships among ten isolates of T.indica collected from different locations of India and 15 monosporidial lines raised from these isolates were investigated by using 34 RAPD and 28 ISSR primers. RAPD and ISSR primers revealed 92.82 and 98.4 % polymorphism, respectively. Similarity coefficient values ranged from 0.61 to 0.97 for RAPD and 0.61 to 0.96 for ISSR primers. The dendrogram developed by RAPD and ISSR primers based analysis grouped the isolates and monosporidial lines in different clusters. Mental test employed for detection of goodness of fit established cophenatic correlation value for both the primer systems and it was significant at P 0.01. Clustering of isolates within groups was also similar based on RAPD and ISSR derived dendrograms. In our study, both marker systems were similar except for the percentage polymorphism which was found to be greater using ISSR, thus indicating the greater effectiveness of ISSR primers for estimating genetic diversity of Tilletia indica.