肚倍蚜春迁期寄主植物挥发物的组成特点

Composition of volatiles released from spring migrant Kaburagia rhusicola Takagi host plants

肚倍生产的可持续发展有赖于蚜虫和寄主的协同共生,本文研究对肚倍蚜迁飞具有引诱效应的相关寄主植物挥发物组成状况。在湖北竹山县3处不同海拔高度分别采集春迁蚜主要迁飞阶段的冬寄主美灰藓和夏寄主青麸杨自然状态挥发物,并以全自动热脱附-气相色谱/质谱(ATD-GC/MS)联用法分析其化合物成分。结果表明,冬春交替时期,受相关寄主植物中挥发性次生代谢物释放诱导,肚倍蚜集中从冬寄主向夏寄主迁飞;各寄主挥发物样品中检出的萜烯类成分均在总含量中占最大比例,当迁飞进程由初期进入高峰期、末期时,α-蒎烯等较高含量萜类在夏寄主青麸杨挥发物中占比更为突出。在3个采样点,均是青麸杨挥发物中萜烯所占比例相对美灰藓更高,迁飞初期即超过50%,至高峰期及末期更扩大占比,成为主导类化合物。此外,由于气温原因,在相对较低海拔处,萜烯类的挥发优势效应更凸显,春迁蚜的迁飞进程可相对更早发生。

The sustainable development of Kaburagia rhusicola Takagi production depends on harmonious intergrowth between the aphid and its host.It is necessary to investigate the composition of host plant volatiles which can induce migration of the aphid.Such volatile samples were collected fromRhus potaninii Maxim and Eurohypnum leptothallum（C.Muell.）Ando.during the main stages of the aphid migration in early spring,varying at 3altitude levels in Zhushan County,Hubei Province.Volatile compounds were analyzed by automatic thermal-desorption gas chromatography/mass spectrometry（ATD-GC/MS）.Results showed that K.rhusicola migrated from its winter host to summer host during the period of seasonal change between winter and spring,which could be induced by volatile secondary metabolites released from such host plants.Among all components determined in each sample,terpenes were predominated compounds with the highest relative contents in volatiles.As the migration progressing from early to the peak and late periods,terpenes with high content ofα-pinene achieved more predominant ratio in the volatiles from summer host.In three sampling sites,the ratio of terpene content of R.potaninii volatiles was higer than that of E.leptothallum.The ratio was over 50% at the beginning of migration and enlarged at the peak and late period,so terpenes were the predominating chemicals in the volatiles.For reasons such as temperature,the advantage effect of terpene volatility was much stronger at the relatively low altitude levels,where the spring migration would occur earlier.