Singh T V K, Kukanur Vinod S, G B Supriya
Department of Entomology, Prof. Jayashankar Telangana State Agricultural University, Hyderabad 500 030, Telangana, India.
Department of Entomology, Prof. Jayashankar Telangana State Agricultural University, Hyderabad 500 030, Telangana, India; International Crops Research Institute for Semi-arid Tropics, Hyderabad, India.
J Invertebr Pathol. 2021 Jul;183:107559. doi: 10.1016/j.jip.2021.107559. Epub 2021 Feb 19.
Transgenic cotton expressing Bacillus thuringiensis (Bt) cry1Ac and cry2Ab toxin genes is widely cultivated to manage bollworm complex in India. Cotton bollworm Helicoverpa armigera (Hübner) is one of the most serious of this complex. It is likely to evolve resistance to Cry toxins in view of continual selection pressure due to extensive cultivation of Bt cotton. Monitoring susceptibility of cotton bollworm using conventional bioassays is reported to have shown its increasing tolerance to Cry1Ac over the years. We report using an F screen Cry1Ac resistance allele frequencies of 0.050 (95% CI 0.022-0.076) and 0.056 (95% CI 0.035-0.075) in the insect populations collected from pigeon pea grown alongside Bt cotton in the respective years of 2016 and 2017 in the Telangana state of India. Compared to our earlier studies for 2013 and 2014, resistance allele frequency to Cry1Ac in the cotton bollworm in the following two years remains unchanged. The significance of these results is discussed in the context of non-Bt host crops acting as refuge for cotton bollworm for ensuring sustainable resistance management.
表达苏云金芽孢杆菌（Bt）cry1Ac和cry2Ab毒素基因的转基因棉花在印度被广泛种植，用于防治棉铃虫复合体。棉铃虫Helicoverpa armigera（Hübner）是该复合体中最严重的害虫之一。鉴于Bt棉花的广泛种植带来的持续选择压力，棉铃虫很可能会对Cry毒素产生抗性。据报道，使用传统生物测定法监测棉铃虫的敏感性显示，多年来其对Cry1Ac的耐受性在增加。我们报告称，在印度特伦甘纳邦2016年和2017年分别从与Bt棉花间作的木豆上采集的昆虫种群中，使用F筛选法测得Cry1Ac抗性等位基因频率分别为0.050（95%置信区间0.022 - 0.076）和0.056（95%置信区间0.035 - 0.075）。与我们之前2013年和2014年的研究相比，接下来两年棉铃虫中Cry1Ac的抗性等位基因频率保持不变。在非Bt寄主作物作为棉铃虫避难所以确保可持续抗性管理的背景下，对这些结果的意义进行了讨论。
