Submitted to: Biological and Cultural Tests for Control of Plant Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/10/1999
Publication Date: N/A
Citation: Interpretive Summary: Tomato spotted wilt virus (TSWV) is a relatively new disease in the U.S. peanut production areas. This virus can cause serious yield losses and there are no effective chemical control measures. The objective of this study was to examine advanced peanut breeding lines from four breeding programs for their reaction to TSWV. Eighteen breeding lines, a highly susceptible cultivar, and a moderately resistant cultivar were grown in two locations. Six of the breeding lines showed a significantly higher level of resistance to TSWV than the moderately resistant cultivar. Six breeding lines had significantly higher yield than the moderately resistant cultivar. This information will be used to determine which of these breeding lines have the potential to be released as cultivars.
Technical Abstract: Experiments were conducted at the Univ. of Georgia, Coastal Plain Expt. Station, Lang Farm, Tifton, GA and at the North Florida Research and Education Center, Marianna, FL. Randomized complete block designs with six replications were used in both locations. Thrips and TSWV were endemic at both locations. Genotypes evaluated included runner-type lines from breeding programs at the Univ. of Florida, the Univ. of Georgia, the USDA, and Agratech Seeds. Entries also included Georgia Runner and Georgia Green as susceptible and moderately resistant standards. All tests were maintained as recommended for commercial production. Plants were inverted at approximate optimum maturity at each location. Pods were harvested mechanically, and pod yields were determined for each plot. Five spotted wilt ratings were made (2-3 wk intervals) during the season. The number of 0.31-m portions of row containing plants severely affected by spotted wilt were counted in each plot, and the percentage of row length severely affected was calculated. Five evaluations were made, with final intensity (FI) ratings made just before digging. Area under the disease progress curve (AUDPC) was calculated for each plot, and AUDPC and FI ratings were used for comparison of genotypes. Epidemics of spotted wilt were severe at both locations. Location x genotype effects on AUDPC's were significant. Two breeding lines had lower AUDPC values than Georgia Green at both locations. There was no significant location x genotype interaction for FI ratings or yield. Across locations, FI ratings were higher in Georgia Runner than in all but one of the other genotypes. Six entries had lower FI ratings than Georgia Green, and six entries had higher yields than Georgia Green.