Seed-borne Curvularia lunata deteriorating seed health and germination of soybean

Seed health plays a pivotal role in profitable crop production. However, seed-borne pathogens deteriorate seed health and reduce the market value of crops. Curvularia lunata is an important fungus associated with seeds of several crops. In the present study, broken, discolored and unhealthy seeds were observed during the inspection of soybean germplasm entries indicative of a fungal disease. The suspected fungus was isolated from these seeds using blotter paper and potato dextrose agar. Purified growth of fungus on nutrient media was smooth, regular and conidia were curved which appeared to be C. lunata . DNA was isolated and Internal transcribed spacer (ITS) region was amplified. The amplicon (550 bp) of three isolates NBGCLI-III were sequenced. NCBI BLASTn confirmed assembled sequences as C. lunata . These sequences were submitted to NCBI GenBank with accession numbers OP093623-25. Soybean seeds were also subjected to culture filtrate of these isolates. Inoculated seeds showed reduced germination and the seedlings produced were abnormal as observed earlier when compared to untreated control. From infected seeds fungal DNA was isolated and ITS region was amplified and sequenced. The sequence results confirmed the presence of C. lunata . Hence, the present study has shown the deleterious effects of C. lunata on seed health in soybean and suggests the use of diseased-free seeds for better germination and vigorous crop.