Dively Galen P, Kuhar Tom P, Taylor Sally V, Doughty Helene, Holmstrom Kristian, Gilrein Daniel O, Nault Brian A, Ingerson-Mahar Joseph, Huseth Anders, Reisig Dominic, Fleischer Shelby, Owens David, Tilmon Kelley, Reay-Jones Francis, Porter Pat, Smith Jocelyn, Saguez Julien, Wells Jason, Congdon Caitlin, Byker Holly, Jensen Bryan, DiFonzo Chris, Hutchison William D, Burkness Eric, Wright Robert, Crossley Michael, Darby Heather, Bilbo Tom, Seiter Nicholas, Krupke Christian, Abel Craig, Coates Brad S, McManus Bradley, Fuller Billy, Bradshaw Jeffrey, Peterson Julie A, Buntin David, Paula-Moraes Silvana, Kesheimer Katelyn, Crow Whitney, Gore Jeffrey, Huang Fangneng, Ludwick Dalton C, Raudenbush Amy, Jimenez Sebastian, Carrière Yves, Elkner Timothy, Hamby Kelly
Department of Entomology, University of Maryland, College Park, MD 20742, USA.
Department of Entomology, Virginia Tech, Blacksburg, VA 24060, USA.
Insects. 2023 Jun 25;14(7):577. doi: 10.3390/insects14070577.
Transgenic corn and cotton that produce Cry and Vip3Aa toxins derived from (Bt) are widely planted in the United States to control lepidopteran pests. The sustainability of these Bt crops is threatened because the corn earworm/bollworm, (Boddie), is evolving a resistance to these toxins. Using Bt sweet corn as a sentinel plant to monitor the evolution of resistance, collaborators established 146 trials in twenty-five states and five Canadian provinces during 2020-2022. The study evaluated overall changes in the phenotypic frequency of resistance (the ratio of larval densities in Bt ears relative to densities in non-Bt ears) in populations and the range of resistance allele frequencies for Cry1Ab and Vip3Aa. The results revealed a widespread resistance to Cry1Ab, Cry2Ab2, and Cry1A.105 Cry toxins, with higher numbers of larvae surviving in Bt ears than in non-Bt ears at many trial locations. Depending on assumptions about the inheritance of resistance, allele frequencies for Cry1Ab ranged from 0.465 (dominant resistance) to 0.995 (recessive resistance). Although Vip3Aa provided high control efficacy against , the results show a notable increase in ear damage and a number of surviving older larvae, particularly at southern locations. Assuming recessive resistance, the estimated resistance allele frequencies for Vip3Aa ranged from 0.115 in the Gulf states to 0.032 at more northern locations. These findings indicate that better resistance management practices are urgently needed to sustain efficacy the of corn and cotton that produce Vip3Aa.
产生源自苏云金芽孢杆菌(Bt)的Cry和Vip3Aa毒素的转基因玉米和棉花在美国被广泛种植,用于防治鳞翅目害虫。这些Bt作物的可持续性受到威胁,因为棉铃虫正在对这些毒素产生抗性。合作者利用Bt甜玉米作为哨兵植物来监测抗性的演变,在2020年至2022年期间在25个州和5个加拿大省份开展了146项试验。该研究评估了棉铃虫种群中抗性表型频率的总体变化(Bt穗中幼虫密度与非Bt穗中幼虫密度的比率)以及Cry1Ab和Vip3Aa抗性等位基因频率的范围。结果显示对Cry1Ab、Cry2Ab2和Cry1A.105 Cry毒素存在广泛抗性,在许多试验地点,Bt穗中存活的幼虫数量多于非Bt穗。根据对抗性遗传的假设,Cry1Ab的等位基因频率范围从0.465(显性抗性)到0.995(隐性抗性)。尽管Vip3Aa对棉铃虫具有较高的防治效果,但结果显示穗部损害和存活大龄幼虫数量显著增加,尤其是在南部地区。假设为隐性抗性,Vip3Aa的估计抗性等位基因频率范围从海湾州的0.115到更北部地区的0.032。这些发现表明,迫切需要更好的抗性管理措施来维持产生Vip3Aa的玉米和棉花的防治效果。