Evaluation of Groundnut Germplasm for Late Leaf Spot Resistance

Groundnut (Arachis hypogaea L.) is a vital global oilseed crop whose productivity is severely constrained by late leaf spot (LLS) disease, caused by Nothopassalorapersonata, which can cause yield losses of 50-70%. Developing resistant cultivars is the most sustainable management strategy. This study aimed to screen 21 groundnut genotypes for LLS resistance during Kharif 2024. Screening was conducted using a 1–9 visual scale at 75 and 85 days after sowing (DAS) to assess both early and progressive disease reactions. The results identified GPBD-4, KDG-128, and JL-776 as parental lines with stable resistance at both growth stages. Among segregating populations, crosses involving these resistant parents, particularly JL-776 × KDG-128 and JL-776 × GPBD-4, demonstrated consistent and durable resistance across the F₁, F₂, and backcross generations. The study confirms that these genotypes are reliable sources of resistance alleles. The cross combinations JL-776 × KDG-128 and JL-776 × GPBD-4 are identified as excellent breeding material for developing high-yielding, resilient groundnut cultivars with durable LLS resistance.