黄瓜花叶病毒侵染烟草对烟蚜生长发育、取食和选择行为的影响

Effects of CMV-Infected Tobacco on the Performance,Feeding and Host Selection Behavior of Myzus persicae

【目的】探明黄瓜花叶病毒(cucumber mosaic virus,CMV)侵染烟草对烟蚜(Myzus persicae)生长发育和行为的影响,研究CMV 2b基因在烟蚜与CMV互作中的作用。【方法】供试寄主植物为健康烟草和CMV侵染、CMV 2b基因缺失突变体(CMVΔ2b)侵染烟草,利用Y型嗅觉仪测定烟蚜对不同烟草寄主的选择趋向;利用刺吸电位图谱(electrical penetration graph,EPG)监测烟蚜取食行为,并结合寄主植物内总糖和游离氨基酸含量分析CMV侵染对烟蚜取食行为的影响;通过单株微虫笼记录蚜虫生命参数并分析CMV侵染烟草对烟蚜生长发育和繁殖的影响。【结果】CMV侵染烟草叶片中总糖含量显著低于健康烟草,而游离氨基酸的含量显著高于健康烟草和CMVΔ2b侵染烟草。CMVΔ2b侵染烟草中的苏氨酸、谷氨酸、甘氨酸、酪氨酸、组氨酸、精氨酸和脯氨酸含量显著高于其他处理烟草,缬氨酸和赖氨酸含量显著高于健康烟草;而CMV侵染烟草中的天冬氨酸含量显著低于其他处理烟草,其胱氨酸含量显著高于CMVΔ2b侵染烟草。相较于CMV侵染烟草,烟蚜对健康烟草和CMVΔ2b侵染烟草有着更强的选择趋向,而烟蚜对健康烟草与CMVΔ2b侵染烟草的选择行为无显著差异。CMV侵染烟草对烟蚜的生长发育和取食行为产生不利影响。烟蚜在CMV侵染烟草上的刺探行为(pd波)发生次数最多,韧皮部取食(E2波)的持续时间最短,且木质部吸食(G波)的发生频率显著高于健康烟草和CMVΔ2b侵染烟草,表明CMV侵染烟草不适宜烟蚜取食。烟蚜的生长特性试验表明CMV侵染烟草显著延长了烟蚜的若蚜历期,提高了2龄若蚜的死亡率,缩短了烟蚜的寿命,显著降低了烟蚜繁殖力。CMV侵染烟草上烟蚜的内禀增长率(r)和周限增长率(λ)均显著低于健康烟草和CMVΔ2b侵染烟草,CMV的侵染不利于烟蚜种群的增长。【结论】CMV侵染改变了烟草营养物质组成,CMV 2b基因的存在增加了烟蚜刺探频率,减少了烟蚜在烟株上的韧皮部取食;CMV侵染导致烟蚜若蚜历期延长、死亡率增加,烟蚜寿命和繁殖力均显著降低;CMV侵染降低了烟蚜的寄主适合度,促使蚜虫向新寄主植物转移,从而促进了病毒的扩散传播。

【Objective】The objective of this study is to investigate the effect of cucumber mosaic virus(CMV)infection on the growth,development and behavior of Myzus persicae on tobacco,and the role of 2b gene in the interaction between M.persicae and CMV.【Method】The host plants to be used were healthy tobacco,CMV-infected and CMV 2b gene deletion mutant(CMVΔ2b)infected tobacco.The Y-shaped olfactometer was used to determinate the selection tendency of M.persicae to different host tobacco plants,and electrical penetration graph(EPG)was used to monitor M.persicae feeding behavior combined with the detection of total sugar and free amino acid content in the host plant.The aphid life table was recorded through a single micro-cage to analyze the effects of CMV-infected tobacco on the growth and reproduction of M.persicae.【Result】The total sugar content of CMV-infected tobacco was significantly lower than that of healthy tobacco,while the content of free amino acids was significantly higher than that of healthy tobacco and CMVΔ2b-infected tobacco.The contents of threonine,glutamic acid,glycine,tyrosine,histidine,arginine and proline in the tobacco infected by CMVΔ2b were significantly higher than those of other treatments.The contents of valine and lysine in CMVΔ2b-infected tobacco were significantly higher than those of healthy tobacco.The content of aspartic acid in CMV-infected tobacco was significantly lower than that of other treatments,and its cystine content was significantly higher than that of CMVΔ2b-infected tobacco.Compared with CMV-infected tobacco,M.persicae had a stronger selection trend to healthy tobacco and CMVΔ2b-infected tobacco.There was no significant difference in the host selection behavior of M.persicae between healthy tobacco and CMVΔ2b-infected tobacco.CMV infection adversely affected the growth and feeding behavior of M.persicae.M.persicae had the most frequent probing behavior(pd wave)and the shortest duration of phloem feeding(E2 wave)on CMV-infected tobacco,and the frequency of xylem feeding(G wave)was significantly higher than that of healthy tobacco and CMVΔ2b-infected tobacco.The results indicated that CMV-infected tobacco was not suitable for aphid feeding.The growth characteristics of the M.persicae showed that CMV infection significantly prolonged the duration of the nymph aphid,increased the mortality rate of the 2nd-instar aphid,reduced the longevity of the aphid,and significantly reduced the fecundity of the aphid.The intrinsic rate of increase(r)and finite rate of increase(λ)of M.persicae on CMV-infected tobacco were significantly lower than those of healthy and CMVΔ2b-infected tobacco.CMV infection was not conducive to population growth of M.persicae.【Conclusion】CMV infection changes the composition of tobacco nutrients.The presence of CMV 2b gene increases the probing frequency and reduces the phloem feeding behavior.CMV infection results in prolonging pre-adult period,increasing mortality,decreasing longevity and fecundity of M.persicae.CMV infection reduces the host fitness of M.persicae,promotes aphids to transfer to new host plants,thus promoting the spread of the CMV.