Screening for resistance of sunflower germplasm lines against collar rot disease incited by Sclerotium rolfsii Sacc.

The present study was carried out under natural field conditions in the research field of Oilseeds Section, Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar to test resistance/ tolerance of sunflower germplasm lines against Sclerotium rolfsii. A total of hundred germplasm lines of sunflower were screened for their relative resistance against collar rot disease in field under natural conditions. Each genotype was planted in single rows with a row length of 3 m and a row spacing of 60 x 30 cm in augmented design and disease incidence were recorded. Among one hundred germplasm line forty-four was showed moderately resistant, thirty-six germplasm lines were showed moderately susceptible reaction, sixteen germplasm lines showed susceptible reaction (40-60%), while four lines were highly susceptible to collar rot disease under natural field conditions.