Strydom Elrine, Erasmus Annemie, Friis Stephanus, Magson Jacques, Parimi Srinivas, Martinelli Samuel, Head Graham P, du Plessis Hannalene, van den Berg Johnnie
Agricultural Research Council - Grain Crops, Potchefstroom, South Africa.
Bayer Crop Science, Johannesburg, South Africa.
Pest Manag Sci. 2025 Mar;81(3):1307-1315. doi: 10.1002/ps.8529. Epub 2024 Nov 14.
Resistance of Busseola fusca (Lepidoptera: Noctuidae) to Cry1Ab was documented in 2006, 7 years after the first cultivation of MON 810 in South Africa. This was mitigated by introducing a second-generation Bacillus thuringiensis (Bt) maize (MON 89034), which contains the Cry1A.105 and Cry2Ab2 proteins. The first reports of B. fusca infestations of MON 89034 maize came in the KwaZulu-Natal province (2017-2018 cropping season), followed by reports in the Mpumalanga province (2022-2023 season). Here we report results of artificial diet- and plant-based laboratory assays to assess the susceptibility of B. fusca populations to the Bt proteins in MON 89034.
Larvae were sampled from nine locations which included three where greater than expected injury due to B. fusca had been reported to MON 89034. Larval mortality in assays with diet-incorporated Cry2Ab2 protein was 100% for all except the three problem populations, showing that the Cry2Ab2 protein in MON 89034 is highly efficacious against B. fusca. In contrast, assays with Cry1A.105 did not cause significant mortality in any of the B. fusca populations including larvae from a susceptible reference. Larval survival on leaf tissue of MON 89034 maize after 7 days ranged between 75% and 91% for the three problematic B. fusca populations, compared to 0.4% to 9.6% for the five other populations.
Therefore, MON 89034 is effectively a single-mode-of-action technology against B. fusca and carries an inherent high risk for the evolution of resistance. This study shows that the three B. fusca populations collected from locations with greater than expected damage to MON 89034 have resistance to the Cry2Ab2 protein and therefore to MON 89034 maize. This research emphasizes the importance of resistance monitoring and implementation of effective insect resistance management tactics. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
2006年记录到布氏夜蛾（鳞翅目：夜蛾科）对Cry1Ab产生抗性，这是在南非首次种植MON 810七年后。通过引入第二代苏云金芽孢杆菌（Bt）玉米（MON 89034）缓解了这一情况，该玉米含有Cry1A.105和Cry2Ab2蛋白。关于MON 89034玉米遭受布氏夜蛾侵害的首批报告出现在夸祖鲁 - 纳塔尔省（2017 - 2018种植季），随后在姆普马兰加省也有报告（2022 - 2023季）。在此，我们报告基于人工饲料和植株的实验室检测结果，以评估布氏夜蛾种群对MON 89034中Bt蛋白的敏感性。
从九个地点采集幼虫，其中三个地点曾报告MON 89034因布氏夜蛾遭受的损害超出预期。在含有Cry2Ab2蛋白的饲料检测中，除三个问题种群外，所有幼虫的死亡率均为100%，这表明MON 89034中的Cry2Ab2蛋白对布氏夜蛾具有高效性。相比之下，Cry1A.105检测在任何布氏夜蛾种群中均未导致显著死亡，包括来自敏感对照的幼虫。对于三个有问题的布氏夜蛾种群，7天后在MON 89034玉米叶片组织上的幼虫存活率在75%至91%之间，而其他五个种群的存活率为0.4%至9.6%。
因此，MON 89034实际上是一种针对布氏夜蛾的单作用模式技术，具有抗性进化的内在高风险。本研究表明，从对MON 89034造成超出预期损害的地点采集的三个布氏夜蛾种群对Cry2Ab2蛋白具有抗性，因此对MON 89034玉米也具有抗性。本研究强调了抗性监测以及实施有效的抗虫管理策略的重要性。© 2024作者。由John Wiley & Sons Ltd代表化学工业协会出版的《害虫管理科学》
