| Scope and method of study. The objectives of this study were to molecularly characterize Tomato spotted wilt tospovirus (TSWV)-isolates infecting peanut in Texas and Oklahoma and to screen the peanut genotypes for resistance to TSWV under field and controlled conditions. Both nonstructural NSm gene and nucleocapsid N gene of the isolates were cloned, sequenced in order to determine their phylogenetic relations. Reaction of peanut cultivars to TSWV in field plots and their response to mechanical inoculation by TSWV under greenhouse conditions was evaluated. In field plots, disease incidence of spotted wilt in peanut cultivars was determined and also area under disease progress curve was calculated. In greenhouse experiments, different quantitative growth parameters (e.g., root length, root volume, plant height, fresh and dry weight) also, disease severity, virus titer, and relative water content were measured for both control and systemically infected plants inoculated mechanically with TSWV at three interval times.; Findings and conclusions. Twelve NSm and Five N gene proteins of TSWV infecting peanut in Southwest growing area were sequenced. Based on nucleotide and amino acid sequences of NSm and N gene proteins, phylogenetic analysis revealed that TSWV-isolates from Southwest United States formed close cluster that was distinct from other isolates reported previously. Results obtained from field plots indicated that the peanut cultivars Georgia Green, Tamrun-96, and Georgia Hi Oleic represents a potential tool for managing spotted wilt disease in peanut production area in Southwest U.S. and greenhouse experiments results support this finding. |
