寄主植物物理性状及营养物质对地红蝽寄主选择性的影响

【目的】地红蝽Pyrrhocoris tibialis是一种重要的农业植食性害虫，寄主范围广泛。本研究测定地红蝽对不同植物的取食偏好及分析寄主植物物理性状和营养物质在地红蝽成虫寄主选择行为中的作用，以期从寄主理化性状的角度来探讨地红蝽寄主选择行为机制，为指导作物抗虫育种提供依据。【方法】通过自由选择方法研究地红蝽成虫对5种寄主植物(谷子Setaria italica、高粱Sorghum bicolor、绿豆Vigna radiata、大豆Glycine max和玉米Zea mays)叶片的取食选择性；使用Y型嗅觉仪进一步检测地红蝽对5种植物叶片气味的趋性反应；测定分析5种植物叶片物理性状及主要营养物质含量与地红蝽取食选择性的相关性。【结果】地红蝽成虫对5种寄主植物叶片的取食选择率存在显著性差异，依次为谷子＞高粱＞绿豆＝大豆＞玉米，与对这5种寄主植物叶片气味的趋性反应百分率结果一致。相关性分析表明，地红蝽成虫的取食选择性与叶片长宽比、含水量和背面茸毛密度呈显著正相关，相关系数分别为0.881, 0.884和0.906，而与地红蝽成虫取食前后寄主植物叶片可溶性糖含量变化和总蛋白质含量变化呈显著负相关，相关系数分别为-0.915和-0.951。通径分析表明，寄主植物叶片背面茸毛密度和总蛋白质含量变化是地红蝽寄主选择性的重要决定因素。【结论】地红蝽成虫对不同寄主植物存在取食选择和趋向性差异，地红蝽成虫取食选择与寄主植物叶片长宽比、背面茸毛密度、含水量以及可溶性糖和总蛋白质含量变化有关。

Effects of physical characteristics and nutrients of host plants on the host selectivity ofPyrrhocoris tibialis(Hemiptera: Pyrrhocoridae)

【Aim】 Pyrrhocoris tibialis is an important agricultural herbivorous pest with awide host range. In this study, the feeding preference of P. tibialis to different plantswas investigated, and the effects of physical characteristics and nutrients of host plantson the host selection behavior of P. tibialis adults were analyzed to explore the hostselection behavior mechanism of P. tibialis from the perspective of host physical andchemical properties, so as to provide guidance for breeding of insect-resistant crops.【Methods】 The feeding selectivity of P. tibialis adults to leaves of five host plantsincluding Setaria italica, Sorghum bicolor, Vigna radiata, Glycine max and Zea mays wasstudied by free selection method, the taxis responses of P. tibialis to the odors fromleaves of the five plants were detected by Y-tuber olfactometer, and the correlationsbetween the leaf physical characteristics and contents of main nutrients in leaves of thefive host plants and the feeding selectivity of P. tibialis were assayed and analyzed.【Results】 P. tibialis adults showed significant difference in the feeding selection rateto leaves of the five host plants, in a descending order of millet > sorghum > mung bean =soybean > corn, and their percentages of taxis response to the odors from leaves of thefive host plants exhibited the same results. Correlation analysis showed that the feedingselectivity of P. tibialis adults was significantly positively correlated with the bladeaspect ratio, water content and abaxial pubescence density of leaves, with the correlationcoefficients of 0.881, 0.884 and 0.906, respectively, whereas it was significantlynegatively correlated with the changes in soluble sugar and total protein contents inleaves of host plants before and after being fed by P. tibialis adults, with thecorrelation coefficients of -0.915 and -0.951, respectively. Path analysis showed thatthe changes in abaxial pubescence density and total protein content in leaves of hostplants were important determinants of host selectivity of P. tibialis. 【Conclusion】 Thereexist differences in feeding selection and taxis of P. tibialis adults to different hostplants. The feeding selection of P. tibialis adults is related to the blade aspect ratio,abaxial pubescence density, water content, and the changes in soluble sugar and totalprotein contents in leaves of host plants.