Components of Resistance to Late Leafspot in Peanut. I. Levels and Variability - Implications for Selection1

Abstract

Components of resistance to late leafspot (Cercosporidium personatum (Berk. & Curt.) Deighton) in peanut were evaluated for 116 genotypes in three tests during 1986. The tests were conducted in greenhouses at Gainesville and Quincy, Florida and in the field near Marianna, Florida. The components of resistance evaluated were spore incubation period, latent period, lesion number per leaf, percent leaf necrotic area, lesion size, and amount of sporulation. Significant differences were observed in at least one test for each component. The greatest variability among genotypes was observed for lesion diameter and latent period. Resistant genotypes had smaller lesions, longer latent periods, and reducded sporulation. Among the most resistant genotypes were UF81206-1, UF81206-2. 72×32B-3-2-2-2-2-l-b3-B, and US 29-b3-B (85701).