Characterization of Tilletia indica Isolates and Monosporidial Lines by Using Differential Hosts and RAPD Based PCR Markers

Karnal bunt of wheat ranks as one of the major disease of wheat causing quality losses and monetary losses due to international quarantine regulations. In the present investigation, genetic and pathological variation among the ten isolates and 15 monosporidial lines belonged to different locations of North West India was studied. Based on the pathogenic potential, the isolates were categorized into three distinct groups. Most virulent and least aggressive isolates were found KBR1 and KBHP3 scored co-efficient of infection of 70.98 and 6.22, respectively on susceptible variety HD 2009 under artificially inoculated conditions. Fifteen monosporidial lines were inoculated in 20 combinations. Most virulent compatible combination was found in KBH1Md X KBR1Ma, which resulted co-efficient of infection of 74.91. Genetic relationship among Tilletia indica isolates and monosporidial lines was studied by using 34 RAPD primers, which revealed 92.82% polymorphism. Similarity coefficient values ranged from 0.61 to 0.96 and the dendrogram developed by RAPD primers based analysis grouped the isolates and monosporidial lines into two groups. The self paired monosporidial lines raised from the same isolates caused less infection as well as magnitude of variation based on RAPD clustering was also narrow.