假眼小绿叶蝉为害致茶梢挥发物变化及其引诱微小裂骨缨小蜂效应

Changes in Volatiles of Tea Shoots Damaged by Tea Green Leafhoppers and Their Attraction to Schizophragma parvula Ogloblin

以SDE法提取健康茶梢、假眼小绿叶蝉为害茶梢挥发物,用GC-MS配合标准样品从二者中鉴定了17种共有成分,包括顺-3-己烯-1-醇、反-2-己烯醛、芳樟醇、香叶醇、β-紫罗酮和橙花叔醇等常见茶叶香气成分。从前者另外检出顺-3-己烯基丁酸酯等9种成分,还从后者另外测出了己醛等7种成分。假眼小绿叶蝉为害茶梢挥发物各组分总含量、健康茶梢挥发物各组分总含量相对于内标含量的比例分别是1783.8%和360.3%。从蝉害茶梢测出了丰富的反-2-己烯醛、苯甲醛、α-法呢烯和水杨酸甲酯,4种成分占蝉害茶梢、健康茶梢挥发物总量分别为11.8%和8.3%;室内以蝉害茶梢19种主要挥发物的10-2 g/m L剂量为味源,液体石蜡为CK,以Y管嗅觉仪进行行为测定,结果表明这4种成分皆显著引诱微小裂骨缨小蜂(P<0.05)。认为蝉害改变了茶梢挥发性化合物的组成及其相对含量,尤其是产生的反-2-己烯醛、苯甲醛、α-法呢烯和水杨酸甲酯等互利素显著地引诱该叶蝉的卵寄生蜂微小裂骨缨小蜂。

The volatile compounds from healthy intact tea shoots-ITS） and the tea green leafhopper Empoasca vitis-G？the） damaged tea shoots-TGLDTS） were collected by simultaneous distillation extraction-SDE） method, and identified by gas chromatography–mass spectrometry and further confirmed by comparison with synthetic standard samples. Seventeen volatile components shared by both ITS and TGLDTS were identified, including Z-3-hexen-1-ol, E-2-hexenal, linalool, geraniol, β-ionone and nerolidol and other common aromatic compounds. Nine other components including Z-3-hexenyl butyrate were identified only from ITS; whereas, additional seven components including hexanal were detected only from TGLDTS samples. The total volatile contents from TGLDTS and ITS samples were estimated to be 17.84 and 3.6 times as much as the internal standard, respectively. E-2-hexenal, benzaldehyde, ？-farnesene and methyl salicylate were four abundant volatile components from TGLDTS, accounting for 11.8% and 8.3% of total volatile contents of TGLDTS and ITS, respectively. Nineteen synthetic volatile components, identified from TGLDTS, each at a dosage of 10？2 g/m L, were tested in the lab Y-tube olfactometer against a mymarid parasitoid-Schizophragma parvula Ogloblin）. Our bioassay results clearly showed that four of the tested compounds from TGLDTS E-2-hexenal, benzaldehyde, ？-farnesene and methyl salicylate were significantly attractive to the mymarid. The feeding damage by tea green leafhopper seemed to increase the releases of E-2-hexenal, benzaldehyde, ？-farnesene and methyl salicylate that may act as synomone components attracting the egg parastoid of the tea green leafhopper, S. parvula.