Evaluating snap bean germplasm lines for resistance to sweet potato whitefly and associated viruses in Georgia

Snap bean (Phaseolus vulgaris sp.) is a crucial vegetable crop in Georgia, which is the second-largest producer of snap beans in the United States. The sweetpotato whitefly (Bemisia tabaci Gennadius) poses a significant threat to snap bean production, particularly in the fall season. This pest inflicts damage through direct feeding and via transmission of begomoviruses, such as sida golden mosaic virus (SiGMV) and cucurbit leaf crumple virus (CuLCrV). Insecticides are the primary method for managing B. tabaci, but widespread insecticide resistance has been reported in previous studies. Resistant cultivars could offer a viable alternative; however, none are currently available. This study evaluated 15 snap bean germplasm lines for resistance against sweetpotato whitefly and whitefly-transmitted SiGMV and CuLCrV. Greenhouse screening of these lines for resistance to single and mixed infections of CuLCrV and SiGMV revealed that 13 of the lines tested showed significantly lower accumulation of CuLCrV compared to the control, while only six lines showed significantly lower accumulation of SiGMV. Additionally, some lines that showed higher virus accumulation for SiGMV demonstrated reduced symptoms of virus infection. A vector biology study was conducted on selected lines to assess resistance to the vector, the results of which will be discussed.