Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 20, 2009
Publication Date: July 20, 2009
Citation: Li, Y. Culbreath, A.K. Guo, B. Knapp, S.J. Holbrook Jr., C.C. 2009. Tomato spotted wilt and early leaf spot reactions in peanut genotypes from the U.S. and China. Abstract of the American Phytopathological Society Annual Meeting, August 1-5, 2009, Portland, Oregan. Technical Abstract: Tomato spotted wilt, caused by Tomato spotted wilt virus (TSWV), and early leaf spot caused by Cercospora arachidicola are important diseases of peanut (Arachis hypogaea). As part of a study examining genotypic and phenotypic variation, disease reactions to these two diseases were evaluated in twenty-two genotypes from the U.S. and China in field trials at Tifton, GA in 2007-08. There was a continuous range of final incidence of spotted wilt from 20% to 80%, with genotypes UF NC 94022, Georganic, C 689-6-2, Georgia-01R, C724-19-25, C 209-6-13, and Tifguard being the most resistant genotypes for spotted wilt and GTC-20, PE-2, and GTC-9 the most are susceptible genotypes for spotted wilt, with the moderately resistant cultivar Georgia Green and several others with intermediate incidences of spotted wilt. Final percent defoliation by early leaf spot ranged from 10% to 97%. Genotypes C 689-2, Georgia-01R, C 12-3-114-58, C 11-154-6, Tifguard, and Georganic had the lowest levels of defoliation, whereas Georgia Green, NC-6, SunOleic-97R, Spancross, GTC-9 and GTC-20 had the highest levels of defoliation. Disease reactions will be used in conjunction with genetic characterization of these genotypes and populations developed from crosses of selected genotypes in efforts to develop markers for resistance to TSWV and C. arachidicola.