pnut pnut Peanut Science 0095-3679 0095-3679 American Peanut Research and Education Society 10.3146/i0095-3679-15-1-8 Articles Components of Resistance to Late Leafspot in Peanut. I. Levels and Variability - Implications for Selection1 Z. A. Chiteka , D. W. Gorbet , F. M. Shokes , T. A. Kucharek , and D. A. Knauft 2 Former Agronomy Department graduate student (now groundnut breeder, Crop Breeding Institute, Harare, Zimbabwe); Professor of Agronomy, Agricultural Research and Education Center, Marianna 32446; Associate Professor of Plant Pathology, North Florida Research and Education Center, Quincy 32351; Professor of Plant Pathology, Gainesville 32611; and Associate Professor of Agronomy, Gainesville 32611, respectively

1Contribution from the Florida Agric. Expt. Sta. Journal Series No. 8733.

 1 1988 15 1 25 30 7 6 1988 American Peanut Research and Education Society 1988 American Peanut Research and Education Society 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).

 Key Words Arachis hypogaea; , L. groundnuts; , disease resistance; , genetic variability; , Cercosporidium personatum (Berk. and Curt.) Deighton