荔枝异形小卷蛾危害的格木挥发性物质差异分析

Difference Analysis on Volatile Components of Erythrophleum fordii Damaged by Cryptophlebia ombrodelta

荔枝异形小卷蛾(Cryptophlebia ombrodelta)是格木(Erythrophleum fordii)的重要蛀梢害虫,对格木纯林及其混交林的危害差别较大,掌握纯林及混交林叶片和枝条挥发性物质的气相指纹图谱,对荔枝异形小卷蛾成虫取食和产卵趋性及幼虫选择性取食习性的研究具有重要意义。采集格木纯林及格木×桉树、格木×米老排(Mytilaria laosensis)和格木×杉木(Cunninghamia lanceolata)混交林的健康叶片和枝条,通过正己烷溶剂浸提法提取叶片和枝条中的挥发性物质,采用气相色谱法确定挥发性物质的种类和含量。结果表明,纯林受害级别为2级,混交林均为1级。纯林中,格木叶片含9种挥发性物质,枝条含7种,共计16种物质,总峰面积3.09%。格木×桉树混交林中,格木叶片和枝条各含11种挥发性物质;桉树叶片含11种挥发性物质,枝条含20种;共计53种物质,总峰面积8.10%。格木×米老排混交林中,格木叶片含11种挥发性物质,枝条含8种;米老排叶片含20种挥发性物质,枝条含8种;共计47种物质,总峰面积6.93%。格木×杉木混交林中,格木叶片含12种挥发性物质,枝条含7种;杉木叶片含25种挥发性物质,枝条含15种;共计59种物质,总峰面积9.66%。受害级别与物质数量和总峰面积均呈负相关,物质数量与总峰面积呈正相关。纯林和混交林中,格木的挥发性物质种类在数量上变化不大,其他非寄主树种的挥发性物质种类较多,影响荔枝异形小卷蛾种群数量的可能是混交林中非寄主树种的某种或多种挥发性物质。

Cryptophlebia ombrodelta is an important insect pest to Erythrophleum fordii,which damage pure and mixed forests with different degrees.It is of great significance for study of feeding and oviposition orientation of C.ombrodelta adults,and selection of feeding habits of larvae to master vapor phase fingerprints of volatile com⁃ponents in leaves and branches of pure and mixed forests.Healthy leaves and branches of pure forest,E.fordii×eucalypt mixed forest,E.fordii×Mytilaria laosensis mixed forest and E.fordii×Cunninghamia lanceolata mixed forest were collected.Volatile components in leaves and branches were extracted by n-hexane solvent ex⁃traction method.Types and contents of volatile components were detected by gas-chromatography.Results showed that damage degree of pure forest was two,which of mixed forests were one.There were 9 volatile compo⁃nents in leaves and 7 volatile components in branches with total of 16 volatile components and total peak area of 3.09%in E.fordii pure forest.In E.fordii×eucalypt mixed forest,there were 11 volatile components in E.fordii leaves and branches,11 volatile components in eucalypt leaves and 20 volatile components in eucalypt branches with total of 53 volatile components and total peak area of 8.10%.In E.fordii×M.laosensis mixed for⁃est,there were 11 volatile components in E.fordii leaves,8 volatile components in E.fordii branches,20 vola⁃tile components in M.laosensis leaves and 8 volatile components in M.laosensis branches with total of 47 vola⁃tile components and total peak area of 6.93%.In E.fordii×C.lanceolata mixed forest,there were 12 volatile components in E.fordii leaves,7 volatile components in E.fordii branches,25 volatile components in C.lanceo⁃lata leaves and 15 volatile components in C.lanceolata branches with total of 59 volatile components and total peak area of 9.66%.Correlations between damage degree and number of components,total peak area were nega⁃tive.Correlation between number of components and total peak area was positive.In pure and mixed forests,number of volatile components in E.fordii had little differences.Types of volatile components in other non-host plants were more.Factors affected population of C.ombrodelta might be volatile components in leaves and branches of non-host plants.