油菜茎象甲Ceuthorrhynchus asper寄主选择的偏好性及相关植物挥发物分析

Preferences of the rape stem weevil Ceuthorrhynchus asper for plant volatiles from different oilseed rape varieties

【目的】目前油菜茎象甲Ceuthorrhynchus asper Roel的防治主要依赖化学农药,本研究将明确该虫成虫对不同品种油菜的行为选择差异,探究影响该虫寄主选择行为的重要油菜挥发物,为发展绿色防控手段打下基础。【方法】使用Y型嗅觉仪测定油菜茎象甲对不同品种油菜的偏好性;通过顶空固相微萃取和气相色谱-质谱联用技术,鉴定不同品种油菜的挥发物成分,并利用主成分(Principalcomponent analysis,PCA)及偏最小二乘法判别分析(Partial least squares discriminant analysis,PLS-DA)寻找该虫寄主选择相关的重要寄主挥发物。【结果】茎象甲对测试4个油菜品种的选择性明显不同,CKE58和青杂5号对该虫有明显的吸引作用。从4个油菜品种中共鉴定到47种油菜挥发物,包括酯类、醇类、醛类、萜类、烯烃类和烷烃类等;以酯类为主,在各品种中相对含量都高于81%。PCA和PLS-DA分析都显示不同油菜品种挥发物组之间有明显区别,重要的差异性或特征性挥发物包括乙酸叶醇酯、十一醇、乙酸己酯、反-3-己烯醇和反-2-十二碳烯等。【结论】油菜茎象甲对油菜品种CKE58和青杂5号具有显著偏好性。CKE58和青杂5号所含差异性或特征性且含量较高的挥发物可能决定着油菜茎象甲的寄主选择性,这些挥发物主要有乙酸叶醇酯、十一醇、乙酸己酯和反-3-己烯-1-醇等。研究结果能为发展针对油菜茎象甲的新型监测和绿色防控技术打下基础。

[Objectives]To determine the preferences of adult rape stem weevils,Ceuthorrhynchus asper Roel for plant volatiles from different varieties of oilseed rape in order to identify the varieties most attractive to this pest,and thereby provide a basis for developing environmentally-friendly control measures.[Methods]Y-type olfactometers were used to determine the preferences of C.asper for volatiles from different varieties of oilseed rape.Volatile components of different rape varieties were extracted and identified using headspace solid-phase microextraction and gas chromatography-mass spectrometry.Important volatile components of rape varieties were analyzed with Principal Component Analysis(PCA)and Partial Least Squares Discriminant Analysis(PLS-DA).[Results]Adult rape stem weevils significantly preferred volatiles from the CKE58 and Qingza 5 varieties to those from the other two varieties tested.A total of 47 volatile compounds were identified,including esters,alcohols,aldehydes,terpenoids,alkenes and alkanes.Esters were the predominant volatile in every variety,comprising>81%of all volatiles.PCA and PLS-DA analyses indicate significant differences in volatile compounds and their contents among the different oilseed rape varieties.Important or characteristic volatile compounds included(Z)-3-hexyenyl acetate,1-undecanol,hexyl acetate,(E)-3-hexen-1-ol and(E)-2-dodecene,etc.[Conclusion]The rape stem beetle is attracted to the CKE58 and Qingza 5 varieties of oil seed rape.Characteristic volatile components of these varieties,include(Z)-3-hexenyl acetate,1-undecanol,hexyl acetate and€-3-hexen-1-ol,and may play a key role in the host selection behavior of C.asper.These results provide a basis for developing new monitoring and environmentally-friendly control methods for C.asper.