水稻品种对褐飞虱趋向二化螟危害株习性的影响

Effect of Rice Varieties on the Preference of Nilaparvata lugens to Rice Plants Infested by Chilo suppressalis

【目的】褐飞虱(Nilaparvata lugens)具有趋向二化螟(Chilo suppressalis)危害水稻的习性,但此现象是否受到褐飞虱虫态以及水稻品种的影响尚不清楚。论文旨在探究水稻品种和褐飞虱虫态对褐飞虱趋向二化螟危害水稻习性的影响,以及植物挥发物如何介导这一行为,从而为制定绿色防控策略提供科学依据。【方法】通过室内选择试验,观察3种虫态(3—4龄若虫、初羽化雌虫和怀卵雌虫)褐飞虱对二化螟危害及未被危害的中浙优8号等9个水稻品种植株的趋向性;在此基础上,针对具有明显趋向性差异的代表性品种,运用RT-qPCR技术检测中浙优8号、9311和明恢63共3个水稻品种在害虫危害后挥发物合成相关基因的表达变化。【结果】在9个水稻品种下,不同虫态褐飞虱均倾向选择二化螟危害的水稻植株,但这种选择性在水稻品种间有所差异,如褐飞虱初羽化雌虫对明恢63的选择率显著高于甬优538。基因表达分析显示,二化螟的取食显著提高了与植物挥发物合成相关的基因OsCAS、OsLIS、OsHPL3和OsRCI-1的表达量。然而,不同虫态的褐飞虱与二化螟共同取食时,这些基因的表达水平与二化螟单独危害时相比,会出现升高或抑制的情况,具体的影响因虫态而异。【结论】褐飞虱趋向二化螟危害株的习性在所测定的9个水稻品种中普遍存在,但不同虫态在不同水稻品种下的趋向程度有明显差异,不同虫态间主要表现在褐飞虱初羽化雌虫对水稻品种甬优538、中浙优8号与明恢63的选择上;二化螟单独取食或与褐飞虱共同取食均可提高OsCAS、OsLIS、OsHPL3和OsRCI-1的表达水平,表明害虫危害水稻可以调控水稻挥发物的合成,进而影响褐飞虱的寄主选择行为。

【Objective】It has been reported that Nilaparvata lugens(brown planthopper,BPH)exhibits a preference of endangering rice plants infested by Chilo suppressalis(striped stem borer,SSB).However,it remains unclear whether this phenomenon is influenced by the developmental stage of N.lugens and the rice variety.This study aims to investigate the effects of rice varieties and developmental stages of N.lugens on the preference for C.suppressalis-infested rice plants,as well as how volatiles mediate this behavior,so as to provide a scientific basis for formulating green pest control strategies.【Method】Through indoor choice experiments,the attraction of different developmental stages of N.lugens(including 3rd-4th instar nymphs,newly emerged females,gravid females)to nine rice varieties,including Zhongzheyou 8,both damaged and undamaged by C.suppressalis,was observed.Based on these observations,representative varieties showing significant differences in attraction were selected for further analysis.RT-qPCR was used to detect changes in the expression of volatile synthesis-related genes in three rice varieties(Zhongzheyou 8,9311,and Minghui 63)following pest infested.【Result】Among the nine rice varieties,different developmental stages of N.lugens consistently showed a preference for rice plants infested by C.suppressalis,although this preference varied among rice varieties.For instance,newly emerged female N.lugens exhibited a significantly higher preference for Minghui 63 compared to Yongyou 538.Gene expression analysis revealed a significant increase in the expression levels of volatile synthesis-related genes OsCAS,OsLIS,OsHPL3,and OsRCI-1 in response to C.suppressalis infestation.However,when different developmental stages of N.lugens were co-infested with C.suppressalis,the expression levels of these genes could either increase or decrease compared to plants infested only by C.suppressalis,with specific effects depending on the developmental stage of N.lugens.【Conclusion】The preference of N.lugens for rice plants infested by C.suppressalis was commonly observed across the nine tested rice varieties.However,significant differences in the degree of preference were noted among different developmental stages of N.lugens across these varieties.Notably,variations in preference among developmental stages of N.lugens were primarily observed in the selection of rice varieties Yongyou 538,Zhongzheyou 8,and Minghui 63 by newly emerged female.Infestation only by C.suppressalis or in conjunction with N.lugens resulted in increased expression levels of the genes OsCAS,OsLIS,OsHPL3,and OsRCI-1,indicating that pest infestation in rice plants can regulate the synthesis of rice volatiles,thereby influencing the host selection behavior of N.lugens.