亚洲玉米螟对不同玉米品种的取食选择及其中肠酯酶活性反应

Feeding selection for different maize varieties and responses of midgut esterase activity of Ostrinia furnacalis (Guenée)

以近年来在北京地区广泛种植的5个玉米品种(怀研10号、蠡玉6号、中糯2号、甜单21和农大413)为研究材料,用叶碟法测定亚洲玉米螟Ostrinia furnacalis对不同品种玉米叶片取食选择反应,计算取食选择指数,并从生理响应上研究幼虫取食不同品种玉米叶片后中肠酯酶活性变化,分析和阐明不同玉米品种对玉米螟的抗性反应机制。结果表明:玉米螟幼虫对5个供试玉米品种的取食选择指数有一定差异,按寄主种类由大到小顺序为:农大413>甜单21>中糯2号>蠡玉6号>怀研10号,说明不同玉米品种对玉米螟的抗性存在差异。同时,与取食人工饲料的幼虫相比,取食农大413的幼虫其中肠酯酶活性无明显变化,而取食其他玉米品种的幼虫其中肠酯酶活性显著受到抑制,酶活性按所取食寄主种类由大到小顺序为:农大413>甜单21>中糯2号>蠡玉6号>怀研10号,变化趋势与取食选择指数完全一致,表明昆虫取食选择行为、酶活性生理反应与寄主植物抗虫性之间具有协同性,间接反映昆虫与寄主植物之间的相互适应机制。

To clarify the resistance mechanisms of different maize varieties to O. furnacalis, feeding selection of the Asian corn borer for five maize varieties in Beijing, including Huaiyan 10, Liyu 6, Zhongnuo 2, Tiandan 21, and Nongda 413, were tested and the feeding selection indexes were determined. In addition, the responses of larval midgut esterase activity after feeding on these five maize varieties were analyzed. The results showed that the feeding selection indexes of O. furnacalis for the test maize varieties were different significantly, and were ranked as follows：Nongda 413〉Tiandan 21〉Zhongnuo 2〉Liyu 6〉Hua- iyanl0, indicating a difference of resistance to O. furnacalis among maize varieties. Compared to the larvae feeding on artificial diets, the larvae feeding on the variety of Nongda 413 showed no difference in midgut esterase activity while the larvae feeding on the other four maize varieties had lower esterase activities. The activities of midgut esterase of O. furnacalis could also be ranked as follows： Nongda 413〉Tiandan 21〉Zhongnuo 2〉Liyu 6〉Huaiyanl0, consistenting with the trends of feeding selection index. The results obtained in the present study implied that a co adaptation exists between the feeding selection and physiological responses of O. furnacalis and the resistance of maize plants. These findings may assist in the breeding of maize varieties in Beijing and may be helpful for the integrated management of O. furnacalis in fields.