柿树被日本龟蜡蚧危害后挥发物的变化及其对红点唇瓢虫的引诱作用

研究了柿树(DiospyroskakiL.f.)受日本龟蜡蚧(CeroplastesjaponicusGreen)危害后,体内释放出的挥发性物质对天敌昆虫红点唇瓢虫(ChilocoruskuwanaeSilvestri)的招引作用.Y形嗅觉仪测定结果表明,瓢虫趋向受害枝叶的百分率为74.17%,明显大于趋向未受害枝叶的20.00%,t检验证明,二者间差异极显著;而受害轻微枝叶挥发物对红点唇瓢虫的诱导作用与未受害枝叶的诱导效果相比没有显著差异;说明日本龟蜡蚧对柿树的危害可诱导树体挥发性物质发生改变,增加了对红点唇瓢虫的引诱作用.经气相色谱/质谱联用仪(GC/MS)分析发现,柿树未受害枝叶挥发物共有29种组分,烃类物质的相对含量占92.98%;受害枝叶释放出的挥发物组分有32种,烃类物质的相对含量增加到97.15%,另外减少了3种醇类化合物和2种烷烃类化合物,同时合成了8种新的组分,包括4种烃类、3种萜类和1种酮类.这些新合成的化合物极有可能在不同程度上参与了对瓢虫的招引作用.本文揭示了柿树受日本龟蜡蚧危害后,诱导其挥发出对天敌昆虫有引诱作用的化学信息素,为进一步试验确定有效成分和人工筛选模拟引诱剂,开辟生物防治新途径提供了基础依据.图1表2参16

Change in Volatiles of Diospyros Kaki L. f. Damaged by Ceroplastes japonicus Green and Their Attraction to Chilocorus kuwanae Silvestri

Diospyros kaki L. f. (Ebenaceae), which could release volatiles to attract a natural enemy ladybug after damaged by Ceroplastes japonicus Green (Homoptera: Coccidae), was studied in this paper. The result showed that 74.17% damaged twigs and leaves were found attracting Chilocorus kuwanae, and the undamaged ones were only 20.00%. The volatiles of D. kaki could be greatly changed and had a higher attractive ability to C. kuwanae when the host plant was damaged by C. japonicus. The compounds and relative contents of two volatiles were analyzed by gas chromatography/mass spectrum (GC/MS). The volatiles from undamaged twigs and leaves were found with 29 kinds of compounds and 92.98% relative contents of hydrocarbons, and those from damaged ones with 32 kinds and 97.15%. Furthermore, 3 kinds of alcohol and 2 of hydrocarbon disappeared from the volatiles, and 8 new compounds were found, including 4 kinds of hydrocarbon, 3 of terpene and 1 of ketone. These new compounds possibly possessed biological function in attracting C. kuwanae. D. kaki was shown to release infochemicals to attract natural enemies after it was damaged. The result could be used in ensuring infochemicals, simulating attractant and exploring new approach in biological control. Fig 1, Tab 2, Ref 16