Pereira Adriano E, Huynh Man P, Paddock Kyle J, Geisert Ryan W, Calles Torrez Veronica, Knodel Janet J, Moellenbeck Daniel J, Reinders Jordan D, Meinke Lance J, Schneider Sharon K, Coudron Thomas A, Shelby Kent S, Hibbard Bruce E
Plant Genetics Research Unit, USDA-ARS, Columbia, MO 65211, USA.
RNAiSSANCE AG, 1005 North Warson Road, Suite 375, St. Louis, MO 63132, USA.
J Econ Entomol. 2024 Feb 12;117(1):178-186. doi: 10.1093/jee/toad221.
The northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae) is a major pest of maize in the United States Corn Belt. Recently, resistance to Bacillus thuringiensis (Bt) maize was reported in North Dakota and increased use of Bt maize hybrids could facilitate resistance evolution in other maize-producing states. In this study, susceptibility to Bt proteins was evaluated in wild D. barberi populations from 8 fields collected in 5 different states (Minnesota, Missouri, Nebraska, Iowa, and North Dakota). Field populations were compared to a susceptible D. barberi colony in seedling and diet toxicity assays conducted with 3 concentrations of Cry3Bb1 (0.4, 4.0, and 40.0 µg/cm2) and Gpp34/Tpp35Ab1 (previously called Cry34/35Ab1; 1.4, 14.0, and 140.0 µg/cm2). The 2019 population from Meeker Co., Minnesota (MN-2019), exhibited the lowest mortality to Cry3Bb1 and also had nominally lowest mortality to Gpp34/Tpp35Ab1 at the highest concentrations tested in diet toxicity assays. Percent second instar was also highest for larvae of the Minnesota population surviving Cry3Bb1. In seedling assays, MN and IA-2018 populations exhibited the highest proportion survival and dry weight to both proteins expressed in corn. No significant differences in mortality, percent second instar, and dry weight were observed at the highest concentration for both proteins among the populations collected in in 2020. Most D. barberi populations were still highly susceptible to Cry3Bb1 and Gpp34/Tpp35Ab1 proteins based on diet and seedling assays, but resistance appears to be developing in some D. barberi populations. Now that methods are available, resistance monitoring may also be needed for D. barberi in some regions.
北方玉米根萤叶甲，即巴氏根萤叶甲（Diabrotica barberi Smith & Lawrence，鞘翅目：叶甲科），是美国玉米带玉米的主要害虫。最近，北达科他州报道了该害虫对苏云金芽孢杆菌（Bt）玉米产生抗性，而增加Bt玉米杂交种的使用可能会促使其他玉米种植州出现抗性进化。在本研究中，对从5个不同州（明尼苏达州、密苏里州、内布拉斯加州、爱荷华州和北达科他州）的8块田地采集的野生巴氏根萤叶甲种群进行了Bt蛋白敏感性评估。在使用3种浓度的Cry3Bb1（0.4、4.0和40.0微克/平方厘米）和Gpp34/Tpp35Ab1（以前称为Cry34/35Ab1；1.4、14.0和140.0微克/平方厘米）进行的幼苗和饲料毒性试验中，将田间种群与一个敏感的巴氏根萤叶甲菌落进行了比较。明尼苏达州米克县2019年的种群（MN - 2019）对Cry3Bb1的死亡率最低，在饲料毒性试验中测试的最高浓度下，对Gpp34/Tpp35Ab1的死亡率名义上也最低。在Cry3Bb1处理下存活的明尼苏达州种群的二龄幼虫百分比也最高。在幼苗试验中，明尼苏达州和爱荷华州2018年的种群对玉米中表达的两种蛋白的存活率和干重比例最高。在2020年采集的种群中，两种蛋白在最高浓度下的死亡率、二龄幼虫百分比和干重均未观察到显著差异。基于饲料和幼苗试验，大多数巴氏根萤叶甲种群对Cry3Bb1和Gpp34/Tpp35Ab1蛋白仍高度敏感，但一些巴氏根萤叶甲种群似乎正在产生抗性。既然已有可用方法，在一些地区可能也需要对巴氏根萤叶甲进行抗性监测。
