诱导条件对新疆野苹果树挥发物释放的影响

Effects of different inducing conditions on volatiles released from Malus sieversii trees

【目的】比较健康新疆野苹果(Malus sieversii)植株与经过机械损伤、外源茉莉酸甲酯(MeJA)处理和苹果小吉丁虫(Agrilus mali Matsumura)成虫危害后的植株释放挥发物组分及含量的差异,了解不同诱导方法对苹果小吉丁虫寄主植物挥发物释放的影响,为开发高效的植物源诱捕剂奠定基础。【方法】采用顶空-固相微萃取法(HS-SPME)收集不同处理新疆野苹果植株挥发物,并使用气相色谱-质谱联用仪(GC-MS)检测和鉴定挥发物的化学组分及相对含量,同时使用因子分析法和聚类分析法分析其内在联系。【结果】4种不同处理共收集到8大类58种挥发性化合物,以酯类、萜烯类、醇类和醛类为主。与健康对照植株释放的挥发物相比,机械损伤处理植株中顺-3-己烯-1-醇和石竹烯的含量有所增加,α-罗勒烯和芳樟醇的含量有所减少;茉莉酸甲酯处理植株中石竹烯和邻伞花烃的含量有所增加,顺-3-己烯-1-醇和香叶基丙酮的含量有所减少;苹果小吉丁虫危害植株中十一烷醇、芳樟醇、石竹烯等物质的含量有所增加,顺-3-己烯-1-醇、乙酸叶醇酯、α-罗勒烯等物质的含量有所减少。通过因子分析法提取的3个主成分分别能够解释挥发物含量变化总方差的37.65%,23.93%和19.53%,累积反映原信息量的81.11%。聚类分析结果表明,健康和茉莉酸甲酯处理植株首先聚为一类,机械损伤和虫害植株则各自归为一类。【结论】机械损伤、茉莉酸甲酯处理及虫害处理等外界因素会导致新疆野苹果树体内挥发性化合物组分在含量和物质种类上发生明显改变,其中对醇类、酯类和萜烯类物质的诱导效果尤为显著,这些物质与新疆野苹果树-苹果小吉丁虫-天敌的三级营养关系和植物诱导化学防御等可能有紧密联系。

【Objective】Components and relative contents of volatiles released by healthy Malus sieversii trees were compared to those induced by exogenous application of methyl jasmonate（MeJA）,mechanically damaged and harmed by Agrilus mali adults to provide basis for developing effective baits for pest control.【Method】The volatiles from M.sieversii trees were collected by the headspace solid-phase micro extraction method,and the chemical components and relative contents were analyzed using gas chromatography-mass spectrometry（GC-MS）.The principal components and clustering methods were used to determine the internal relations.【Result】A total of 8 categories and 58 volatile compounds were collected under four different treatments,mainly including esters,terpenes,alcohols and aldehydes.Compared with control,the contents of（Z）-3-hexen-1-ol and caryophyllene in mechanically damaged plants increased,while contents ofα-ocimene and linalool decreased.In MeJA treated plants,caryophyllene and o-cymene contents increased and（Z）-3-hexen-1-ol and geranyl acetone contents decreased.In A.mali damaged plants,1-undecanol,linalool and caryophyllene contents increased,while（Z）-3-hexen-1-ol,（Z）-3-hexen-1-ol,acetate,andα-ocimene contents decreased.The first three principal components extracted in the factor analysis explained 37.65%,23.93% and 19.53% of the total variance with a total of 81.11%.The MeJA treated and healthy trees were grouped into one category,while mechanically damaged plants and A.mali damaged trees belonged to separate categories.【Conclusion】External factors led to changes in components and contents of volatiles released.These volatiles were likely to be related to the Malus sieversii-A.mali-natural enemy tritrophic interactions and induced chemical defenses.