Characterization of colletotrichum species associated with soybean pod blight in soybean growing districts of Chhattisgarh

Introduction Soybean is a globally grown oilseed and pulse crop with India occupying fourth position in soybean production. Pod blight disease in soybean is caused by broad-range pathogens Colletotrichum spp. which are not limited by their host range. Objectives Colletotrichum population from soybean growing districts of Chhattisgarh was analysed using polyphasic morphological & molecular approach. Methods Due to similar morphology of most of the Colletotrichum isolates, species identity could not be resolved morphologically. Therefore PCR based sequencing was done. Results Typical conidial morphology of C. Truncatum was observed with all the isolates except two isolates C27 & C28. ITS sequencing approach identified twenty three isolates as Colletotrichum truncatum. Species identity could not be delineated to one of the Colletotrichum isolate C19. Chromosomal 18S-28S rRNA intervening DNA sequences analysis of two isolates C27 and C28 derived from naturally infected pods resolved similarity of these isolates with Paraconiothyrium fuscomaculans (EU754197) and Westerdykella capitulum (GU238054) respectively. Intervening DNA sequences of both occupied sister position in cladogram containing several distantly related species of Colletotrichum. Conclusion Present study on Colletotrichum taxonomy is important in minimizing risk exposure and the likelihood of an incident of disease to the soybean growing areas of Chhattisgarh.