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Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/28/2013 Publication Date: 8/3/2013 Citation: Hesler, L.S. 2013. Resistance to soybean aphid among wild soybean lines under controlled conditions. Crop Protection. 53:139-146. http://dx.doi.org/10.1016/j.cropro.2013.06.016 Interpretive Summary: The soybean aphid is an invasive pest of soybean in the U.S. and Canada, and an occasional pest of soybean throughout its native range in Asia. Large infestations of soybean aphid cause economic loss to soybean through reductions in seed yield and oil concentration. Exploitation of plant resistance within particular soybean lines is a potential alternative to insecticides for managing soybean aphid, and candidate lines may include adapted cultivars, non-adapted landraces, and wild ancestors of soybean. To date, few studies have evaluated wild soybean for resistance to soybean aphid. In this study, initial screening tests indicated 20 wild soybean lines with resistance to soybean aphid, and three of the 20 lines had notable resistance in subsequent sets of tests in which aphids were either allowed or not allowed to choose the soybean lines that they infested. Considerably fewer soybean aphids chose lines PI 468397 A and PI 479749 than susceptible lines, and aphid populations were low and moderately low on these two respective lines in no-choice tests. Population levels of soybean aphid on a third line, PI 549046, were equal to or less than those on a resistant check over 3 wks in a no-choice test. Based on results of the respective choice and no-choice tests, resistance to soybean aphid was manifested as both non-preference and antibiosis in PI 468397 A and PI 479749, and by antibiosis in PI 549046. This is apparently the first report of resistance to soybean aphid in these three lines, and they provide soybean breeders and pest managers new sources for developing aphid-resistant soybean. Technical Abstract: The soybean aphid, Aphis glycines Matsumura, is frequently a serious pest of soybean in the U.S. and Canada, and an occasional pest of soybean throughout its native range in Asia. Large infestations of this aphid cause economic loss to soybean by reductions in seed yield and oil concentration. Host-plant resistance is a potential alternative to insecticides for managing soybean aphid, and various sources may be evaluated, including adapted cultivars, landraces, and wild ancestors of the crop. To date, few studies have evaluated wild soybean for resistance to soybean aphid. In this study, initial screening assays indicated 20 wild soybean lines with resistance to soybean aphid, and three of the 20 lines had notable resistance in subsequent choice and no-choice assays. Significantly fewer soybean aphids settled on lines PI 468397 A and PI 479749 than on susceptible lines in choice assays, and aphid populations were low and moderately low on these two respective lines in no-choice assays. Populations of soybean aphid on a third line, PI 549046, were equal to or less than those on a resistant check over 3 wks in a no-choice assay. Based on results of the respective choice and no-choice assays, resistance to soybean aphid was manifested as both antixenosis and antibiosis in PI 468397 A and PI 479749, and as antibiosis in PI 549046. This is apparently the first report of resistance to soybean aphid in these three lines, and they provide soybean breeders and pest management practitioners new sources for developing aphid-resistant soybean lines. |
