Identification of the Downy Mildew Resistant Sources in Sunflower

Four different evaluation trials were conducted in the field between 2017 and 2020, with varied numbers of genotypes, to evaluate the performance of sunflower genotypes for agromorphological features and resistance to Sunflower Downy Mildew (SDM) at Latur, Maharashtra, India. A validation experiment was carried out in 2021–2022, using artificial screening in National Diseased Plot Screening Facility at Latur, to screen a small number of accessions that had previously shown resistance to SDM during 2017-2020. The released variety "Morden," also susceptible check showed at least 60% of the SDM incidence for four years. This suggests that Plasmopara halstedii spores could be present in the experimental soils, which increases the variety's susceptibility to SDM disease. Out of the tree genotypes that were reported to be resistant in field screening viz., GMU-481 (GP1 909 genotype), Ec-198078, and RHA 1-1 (selection) only two GMU-481 (GP1 909) and Ec-198078 were verified to be resistant under artificial screening in 2021–2022 and can be designated as sources of resistance for SDM disease. These two genotypes with resistance to SDM could be used in future breeding attempts and as potential gene donors for SDM.