P-261 - Field Evaluation of Peanut Genotypes with Wild Arachis Introgressions for Resistance to Early and Late Leaf Spot Pathogens

Enhancing resistance in peanut genotypes to early and late leaf spot diseases is crucial for improving crop resilience and productivity. This study evaluated peanut genotypes with introgressions from wild Arachis species for resistance to early and late leaf spot pathogens, Passaloraarachidicola and Nothopassalorapersonata, with a focus on both early and late stages of disease progression. The research investigates how these wild Arachis introgressions influence resistance and whether early-stage indicators provide insights comparable to traditional assessments.Field evaluations were conducted using the traditional Florida scale and leaf defoliation severity to measure late-stage disease progression. Additionally, early-stage parameters such as lesion incidence, days to sporulation, and sporulation degree were assessed.A strong correlation (R = 0.79) between the Florida scale and leaf defoliation severity emphasized its focus on late-stage disease. While, the lesion incidence showed a moderate correlation (R = 0.57) with the Florida scale, suggesting that resistance can be detected earlier in the disease cycle.Resistant genotypes exhibited significantly longer days to sporulation for late leaf spot (122–132 days) compared to early leaf spot (69–98 days) and significantly lower sporulation degrees for both diseases than susceptible lines (p < 0.001). These findings highlight the potential of these resistant genotypes in peanut breeding programs and suggest the need for further exploration and incorporation of early-stage parameters to enhance resistance assessments.