Characterization of simple sequence repeats (SSRS) markers, genetic diversity analysis in cultivated peanut (Arachis hypogaea L.). amd related leaf spot and spotted wilt responses in the field

Abstract

In this research, as part of a study examining genotypic and phenotypic variation, disease reactions to Tomato spotted wilt virus (TSWV) and Cercospora arachidicola 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%; final percent defoliation by early leaf spot ranged from 10% to 97%. 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 Tomato spotted wilt virus and Cercospora arachidicola. The results of this study corroborated previous reports and confirmed that there is limited genetic diversity in the cultivated peanut. In general, the cluster in Cladogram tree followed our expectations where relationships between genotypes were known. Finally, based on genotypic and phenotypic information, two populations have been developed by crossing of Tifrunner X GT-C20 and SunOleic 97R X NC 94022.