Department of Plant and Environmental Sciences, Clemson University, Pee Dee Research and Education Center, Florence, SC.
Department of Entomology and Plant Pathology, North Carolina State University, the Vernon G. James Research and Extension Center, Plymouth, NC.
J Econ Entomol. 2020 Oct 16;113(5):2241-2249. doi: 10.1093/jee/toaa163.
As part of an ongoing longitudinal study in North and South Carolina, this study reports the recovery of Helicoverpa zea (Boddie) pupae in field trials with genetically engineered corn, Zea mays L., hybrids that produce insecticidal toxins from Bacillus thuringiensis (Bt) in 2017-2019. In total, 10,400 corn ears were collected, which led to 3,927 H. zea pupae (2,215 in South Carolina and 1,712 in North Carolina). Late-planted corn led to a 3.39-fold increase in recovery of pupae compared to early-planted corn. Bt corn expressing Cry1F + Cry1Ab and Cry1A.105 + Cry2Ab2 had 1.67-fold and 2.51-fold fewer pupae than non-Bt near-isolines, respectively. Only six pupae were recovered from the hybrid expressing Cry1F + Cry1Ab + Vip3Aa20. Averaged across trials, Bt corn expressing either Cry1A.105 + Cry2Ab2 or Cry1F + Cry1Ab significantly reduced pupal weight compared to non-Bt near-isolines in North and South Carolina. Combining our data with a previous study at the same locations (Bilbo et al. 2018), reduction in pupal weight between Bt and non-Bt near-isolines significantly declined from 2014 to 2019 for Cry1Ab + Cry1F in North and South Carolina. This decline in levels of a sublethal effect of Bt corn expressing Cry1Ab + Cry1F on H. zea at both locations is likely correlated with resistance development.
作为北卡罗来纳州和南卡罗来纳州正在进行的一项纵向研究的一部分，本研究报告了 2017-2019 年在田间试验中回收转 Bt 基因玉米 Zea mays L. 杂种中 Heliothis zea (Boddie) 蛹的情况，这些杂种能产生苏云金芽孢杆菌（Bt）的杀虫毒素。总共收集了 10400 个玉米穗，其中有 3927 个 H. zea 蛹（南卡罗来纳州 2215 个，北卡罗来纳州 1712 个）。晚播玉米比早播玉米回收的蛹增加了 3.39 倍。表达 Cry1F + Cry1Ab 和 Cry1A.105 + Cry2Ab2 的 Bt 玉米比非 Bt 近等基因系的蛹分别减少了 1.67 倍和 2.51 倍。从表达 Cry1F + Cry1Ab + Vip3Aa20 的杂交种中仅回收了 6 个蛹。平均而言，在北卡罗来纳州和南卡罗来纳州，表达 Cry1A.105 + Cry2Ab2 或 Cry1F + Cry1Ab 的 Bt 玉米与非 Bt 近等基因系相比，蛹重显著降低。将我们的数据与同一地点的先前研究（Bilbo 等人，2018 年）结合起来，在北卡罗来纳州和南卡罗来纳州，Cry1Ab + Cry1F 之间 Bt 玉米和非 Bt 近等基因系的蛹重减少从 2014 年到 2019 年显著下降。这两个地点对 H. zea 表达 Cry1Ab + Cry1F 的 Bt 玉米的亚致死效应水平的下降很可能与抗药性的发展有关。
