Ninety isolates of Colletotrichum lindemuthianum collected from commercial bean growing areas of Himachal Pradesh were characterised on international differential bean varieties and analysed by random amplified polymorphic DNA (RAPD) analysis for elucidation of variability. Virulence analysis of 90 isolates on a differential set categorised them into 29 pathogenic races. Out of these, 12 races resembled American and European virulences, whereas 17 races (101, 103, 115, 119, 131, 195, 537, 551, 581, 598, 613, 615, 631, 639, 707, 775 and 935) were identified as new, thereby enhancing the total race number to more than 140 globally. RAPD data analysis with nine 10-mer random primers producing polymorphic bands, grouped 90 isolates into two major clusters accommodating 36 and 54 isolates, respectively. There was no congruence between the RAPD pattern and virulence phenogram. Interaction analysis among the races and the two Phaseolus vulgaris gene pools indicated that most of the races were virulent on both Andean and Mesoamerican gene pools. Virulence and avirulence interactions between isolates and differential cultivars provided valuable information for resistance to Indian virulences of the anthracnose pathogen, as four differential cultivars (AB 136, Cornell 49242, G 2333 and TO) possessing different resistance genes were resistant to most of the Indian races.
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