Variation among irginia Market-Type Peanut (Arachis hypogaea) Genotypes in Susceptibility to thrips (Thysanopetera: Thripidae) Vectored Tomato Spotted Wilt Virus

Abstract

Tomato spotted wilt virus (TSWV), a thrips-vectored tospovirus remains one of one of North Carolina's most critical pathogens of peanut (Arachis hypogaea). Development of cultivars with resistance to TSWV remains one of the most promising methods to manage the disease. 32 genotypes of virgina market-type peanut were monitored in the field plots for TSWV incidence and severity during 2004 and 2005. Cultivar Gregory had higher adult density then all other genotypes, with genotypes N01057 and N03054E having the least. Genotype NO3036EJ had the greatest TSWV incidence but did not differ significantly from cultivars Gregory or Perry. Genotype N00033 had the least TSWV incidence and differed significantly from both Gregory and Perry. The occurrence of late-season chlorosis (PYD) in North Carolina was confirmed to be highly associated with TSWV infection. Genotype N0205ol (9) had the greatest incidence of PYD, but did not differ significantly from cultivars Gregory or Perry. Genotypes N03023EF and N01083 had the least PYD incidence and differed significantly from both cultivars. TSWV-infected but asymptomatic plants were found in greater abundance then TSWV-infected and symptomatic plants for many genotypes. Genotype N03036EJ had the greatest proportion of infected but asymptomatic plants and differed significantly from Gregory. Genotype N03054E had the least number of infected but asymptomatic plants and differed significantly from Perry but was not different from Gregory. Cultivar NC-V11 had significantly more thrips feeding injury and greater adult density than Perry. No correlation was found between thrips feeding damage or densities and TSWV incidence, PYD incidence, or the number of infected but asymptomatic plants. No significant differences were detected among genotypes for thrips damage ratings or virus severity ratings.