Corteva Agriscience, Mogi Mirim, SP, Brazil.
Corteva Agriscience, Johnston, IA, United States of America.
PLoS One. 2023 Jul 25;18(7):e0289003. doi: 10.1371/journal.pone.0289003. eCollection 2023.
The genetically modified cotton DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 expressing Cry1Ac, Cry1F and Vip3Aa19 from Bacillus thuringiensis Berliner (Bt) has been cultivated in Brazil since the 2020/2021 season. Here, we assessed the performance of DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton expressing Cry1Ac, Cry1F and Vip3Aa19 against Helicoverpa armigera (Hübner), Helicoverpa zea (Boddie), and their hybrid progeny. We also carried out evaluations with DAS-21023-5 × DAS-24236-5 cotton containing Cry1Ac and Cry1F. In leaf-disk bioassays, DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 was effective in controlling neonates from laboratory colonies of H. armigera, H. zea and the hybrid progeny (71.9%-100% mortality). On floral bud bioassays using L2 larvae, H. zea presented complete mortality, whereas H. armigera and the hybrid progeny showed <55% mortality. On DAS-21023-5 × DAS-24236-5 cotton, the mortality of H. armigera on leaf-disk and floral buds ranged from 60% to 73%, whereas mortality of hybrids was <46%. This Bt cotton caused complete mortality of H. zea larvae from a laboratory colony in the early growth stages, but mortalities were <55% on advanced growth stages and on floral buds. In field studies conducted from 2014 to 2019, DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton was also effective at protecting plants against H. armigera. In contrast, a population of H. zea collected in western Bahia in 2021/2022 on Bt cotton expressing Cry1 and Vip3Aa proteins, showed 63% mortality after 30 d, with insects developing into fifth and sixth instars, on DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton. We conclude that H. armigera, H. zea, and their hybrid progeny can be managed with DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton; however we found the first evidence in Brazil of a significant reduction in the susceptibility to DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton of a population of H. zea collected from Bt cotton in Bahia in 2021/2022.
自 2020/2021 季以来，巴西一直在种植经基因改良的棉花 DAS-21023-5×DAS-24236-5×SYN-IR102-7，该棉花表达来自苏云金芽孢杆菌（Bt）的 Cry1Ac、Cry1F 和 Vip3Aa19。在这里，我们评估了表达 Cry1Ac、Cry1F 和 Vip3Aa19 的 DAS-21023-5×DAS-24236-5×SYN-IR102-7 棉花对棉铃虫（Hübner）、玉米螟（Boddie）及其杂种后代的性能。我们还对含有 Cry1Ac 和 Cry1F 的 DAS-21023-5×DAS-24236-5 棉花进行了评估。在叶盘生物测定中，DAS-21023-5×DAS-24236-5×SYN-IR102-7 对实验室饲养的棉铃虫、玉米螟及其杂种后代的幼虫（死亡率为 71.9%-100%）具有有效控制作用。在使用 L2 幼虫的花蕾生物测定中，玉米螟完全死亡，而棉铃虫和杂种后代的死亡率低于 55%。在 DAS-21023-5×DAS-24236-5 棉花上，棉铃虫在叶盘和花蕾上的死亡率为 60%-73%，而杂种的死亡率低于 46%。这种 Bt 棉花在早期生长阶段对来自实验室种群的玉米螟幼虫造成完全死亡，但在后期生长阶段和花蕾上的死亡率低于 55%。在 2014 年至 2019 年进行的田间研究中，DAS-21023-5×DAS-24236-5×SYN-IR102-7 棉花也能有效保护植物免受棉铃虫的侵害。相比之下，2021/2022 年在巴西北部种植 Cry1 和 Vip3Aa 蛋白的 Bt 棉花上采集的玉米螟种群在 30 天后死亡率为 63%，昆虫发育到第五和第六龄期，在 DAS-21023-5×DAS-24236-5×SYN-IR102-7 棉花上。我们得出的结论是，DAS-21023-5×DAS-24236-5×SYN-IR102-7 棉花可以控制棉铃虫、玉米螟及其杂种后代；然而，我们在巴西发现了第一个证据，表明 2021/2022 年在巴西北部种植的 Bt 棉花上采集的玉米螟种群对 DAS-21023-5×DAS-24236-5×SYN-IR102-7 棉花的敏感性显著降低。
