Response of Early, Medium, and Late Maturing Peanut Breeding Lines to Field Epidemics of Tomato Spotted Wilt

Abstract Epidemics of tomato spotted wilt, caused by tomato spotted wilt Tospovirus (TSWV), were monitored in field plots of runner-type peanut (Arachis hypogaea L.) cultivars Georgia Green and Georgia Runner and numerous breeding lines from four different breeding programs as part of efforts toward characterizing breeding lines with potential for release as cultivars. Breeding lines were divided into early, medium and late maturity groups. The tests were conducted near Attapulgus, GA and Marianna, FL in 1997 and in Tifton, GA and Marianna, FL in 1998. Epidemics in some early and medium maturing breeding lines, including some genotypes with high oleic acid oil chemistry, were comparable to those in Georgia Green, the cultivar most frequently used in the southeastern U.S. for suppression of spotted wilt epidemics. No early maturing breeding lines had lower spotted wilt final intensity ratings or higher yields than Georgia Green. However, spotted wilt intensity ratings in some late maturing lines and a smaller number of medium maturing lines were significantly lower than those of Georgia Green. Several of those lines also produced greater pod yields than Georgia Green. Results from these experiments indicated that there is potential for improving management of spotted wilt though development of cultivars that suppress spotted wilt epidemics more than currently available cultivars. There was no indication that differences in spotted wilt ratings corresponded to differences in numbers of thrips adults or larvae.