云南切梢小蠹幼虫表皮碳氢化合物与龄数的相关性  

Correlation between Cuticular Hydrocarbons and Instar Numbers of the Larvae of Yunnan Shoot Borer,Tomicus Yunnanensis(Coleoptera:Scolytidae)

作　　者：张梦蝶 钱路兵 泽桑梓 杨斌[1] 李宗波[1] Zhang Mengdie;Qian Lubing;Ze Sangzi;Yang Bin;Li Zongbo(Key Laboratory of Forest Disaster Warning and Control in Yunnan Province College of Biodiversity Conservation,Southwest Forestry University,Kunming 650224;Yunnan Forestry Pest Control and Quarantine Bureau,Kunming 650224)

机构地区：[1]西南林业大学生物多样性保护学院云南省森林灾害预警与控制重点实验室,昆明650224 [2]云南省林业和草原有害生物防治检疫局,昆明650224

出　　处：《林业科学》2021年第5期151-159,共9页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(31560213,31760210);云南省农业联合专项重点项目(2018FG001-010);云南省万人计划青年拔尖人才项目(51900110)。

摘　　要：【目的】探究一种能准确反映云南切梢小蠹幼虫发育状况的化学分类指标,以便提高虫害预测预报精度及害虫综合管理能力。【方法】基于形态指标,包括头壳宽、体长、上颚长与宽划分龄数,采用气相色谱-质谱联用技术对云南切梢小蠹不同龄数幼虫的正己烷浸提液进行检测,结合谱库检索、科瓦特指数、C8-C40烷烃混合标品等确定化合物种类和含量,用主成分分析和随机森林进行成分分析,并对比龄级间化合物含量的变化。【结果】云南切梢小蠹幼虫表皮碳氢化合物由正链烷烃、支链烷烃和烯烃3类19种化合物组成,正链烷烃以正二十五烷为代表,占比55.02%±8.20%;支链烷烃以13-甲基-二十九烷含量最高,占整个支链烷烃94.04%±14.02%;烯烃类以1,21-二十二烷二烯为主,占比63.03%±0.39%。随幼虫龄数增加,碳数、碳链长度和种类均明显增加,含量呈指数级递增(y=e 0.0865x-0.629,R=0.911),其中1龄幼虫有8种,含量为每虫2.32 ng±0.59 ng;2龄幼虫有8种,含量为每虫44.40 ng±11.46 ng;3龄幼虫有17种,含量为每虫280.75 ng±72.48 ng。第一主成分和第二主成分联合贡献率为81.7%,可将不同龄数的云南切梢小蠹幼虫明显区分开,龄级与龄级间无重叠,划分的标准明显优于形态指标法;化合物2,6,11-三甲基-十二烷、正十五烷、正十九烷、正二十三烷、正二十五烷具有较大的重要性,龄级间含量亦有显著差异(P<0.0001),2,6,11-三甲基-十二烷可用于1龄幼虫的标识性物质,正二十三烷和正二十五烷可识别2龄和3龄幼虫。【结论】云南切梢小蠹不同龄数幼虫的表皮碳氢化合物种类与含量有显著差异,2,6,11-三甲基-十二烷可用于1龄幼虫识别,正二十三烷和正二十五烷可用于识别2龄和3龄幼虫,幼虫表皮碳氢化合物能作为划分龄数的最佳分类指标。【Objective】This study aims to find a suitable bioindicator of chemotaxonomic characters reflecting the developmental stage of the larvae of Yunnan shoot borer Tomicus yunnanensis( Coleoptera: Curculionoidea: Scolytidae) in order to further improve the comprehensive ability of scientifically integrated management on the insect pest and the forecasting accuracy. 【Method】The instar numbers were determined based on morphological indexes,including head capsule width,body length,maxilla length and width. Cuticular hydrocarbons were extracted by immersing larval individuals of different instar numbers in the pure n-hexane. The hydrocarbon extracts were analyzed by using gas chromatograph mass spectroscopy( GC-MS). The kinds and contents of compounds were determined by matching MS library and confirmed by comparison of Kovat ’s index( KI) and C8-C40 alkane mixture standards. The principal component analysis and random forest analysis were used to analyze the chemical composition and compare the changes of the composition of cuticular blends among age classes. The content among the larval instars was also compared by KruskalWallis test. 【Result 】The cuticular hydrocarbons of T. yunnanensis larvae were composed of nineteen compounds that contained n-alkanes,branched alkanes and alkenes. Their amounts are orderly dominated by N-pentadecane was the representative of n-alkanes,accounting for 55.02% ± 8.20%,the content of 13-methyl-docosecane accounted for 94.04% ±14.02% of the total branched alkanes,the highest,and the main alkenes were 1,21-docosadiene,accounting for63. 03% ± 0.39%. With the development of larval instars,both length and kind of carbon chains increased significantly.The content increased exponentially( y = e0.086 5 x-0.629,R = 0.911). There were 8 kinds of hydrocarbon components in the 1 st instar larvae,and the content was( 2.32±0.59) ng·ind-1. There were 8 hydrocarbon components in the 2 ndinstar larvae,and the content was( 44.40 ± 11.46) ng·ind-1. There were 17 hydrocarbon components i

关 键 词：云南切梢小蠹 幼虫 表皮碳氢化合物 微量化合物 龄级 戴尔氏法则 

分 类 号：S763.301[农业科学—森林保护学] Q965[农业科学—林学]