绿带妒尺蛾对寄主的趋性选择及寄主植物叶片的化学成分分析

  目的  通过研究绿带妒尺蛾Phthonoloba viridifasciata幼虫对寄主植物的趋向反应和对寄主植物叶片的化学成分分析，为后续研发绿带妒尺蛾引诱剂提供科学依据。  方法  在室内用培养皿测定了在不同叶碟组合下，绿带妒尺蛾2龄幼虫对不同叶碟的趋性选择。使用正己烷制作寄主植物样品粗提物，气相色谱-质谱联用仪(GC-MS)分析寄主植物嫩叶浸提物的化学成分。使用卡方检验比较绿带妒尺蛾幼虫对不同处理的趋性选择。  结果  ①光照和黑暗条件下，桫椤Alsophila spinulosa和小黑桫椤Alsophila metteniana分别与绿色叶碟配对时，绿带妒尺蛾幼虫对桫椤和小黑桫椤的选择频次极显著高于对绿色叶碟的选择频次(P＜0.01)。光照条件下的选择率(桫椤68.7%，小黑桫椤78.3%)略低于黑暗条件下的选择率(桫椤81.7%，小黑桫椤80.0%)。②黑暗条件下，绿带妒尺蛾幼虫对寄主植物桫椤和小黑桫椤的选择频次极显著高于对非寄主植中华复叶耳蕨Arachniodes chinensis和肾蕨Nephrolepis auriculata的选择频次(P＜0.01)。③黑暗条件下，4种蕨类植物叶碟共存时，绿带妒尺蛾幼虫对桫椤的选择频次显著高于对其他3种蕨类植物的选择频次(P＜0.05)，其中对桫椤的选择频次最高，达46次，占总频次的38.3%。④桫椤和小黑桫椤的化学组分主要是烃类，其次是醇类、醛类等，GC-MS共检测出30余种化合物，其中桫椤23种，小黑桫椤19种，2种植物相同组分有γ-谷甾醇、豆甾烷醇、对甲氧基肉桂酸辛酯、壬醛和其他烷烃等8种化合物。  结论  绿带妒尺蛾幼虫鉴别寄主植物和非寄主植物能力较强，能被寄主桫椤和小黑桫椤所吸引。在桫椤中存在的叶醇和壬醛有望作为绿带妒尺蛾的引诱剂成分。图2表4参38

Host selection of Phthonoloba viridifasciata and analysis of chemical compounds in leaves of host plants

  Objective  This study aims to investigate the tropism response of Phthonoloba viridifasciata larvae to host plants and chemical compounds in leaves of host plants, so as to provide scientific reference for the development of attractants for P. viridifasciata.   Method  The selection of the 2nd instar larvae of P. viridifasciata to different leaf disc combinations was determined by petri dishes in the laboratory. The crude extracts of host plants were prepared with hexane and the chemical compounds were analyzed by gas chromatography-mass spectrometry (GC-MS). Chi square test was used to compare the taxis selection of the larvae of P. viridifasciata to different treatments.   Result  (1) Under light and dark conditions, the selection frequency of P. viridifasciata towards Alsophina spinulosa and A. metteniana were significantly higher than that towards green leaf discs (P＜0.01) when A. spinulosa and A. metteniana were paired with green leaf discs. Under light conditions, the selection ratio under light (A. spinulosa 68.7%, A. metteniana 78.3%) was slightly lower than that under darkness (A. spinulosa 81.7%, A. metteniana 80.0%). (2) Under dark conditions, the selection frequency of the larvae of P. viridifasciata to the host plants A. spinulosa and A. metteniana were significantly higher than that to the non-host plants Arachniodes chinensis and Nephrolepis auriculata (P＜0.01). (3) Under dark conditions, when the leaves and discs of 4 ferns coexisted, the selection frequency of A. spinulosa by the larvae of P. viridifasciata was significantly higher than that of the other 3 ferns (P＜0.05), in which the selection frequency of A. spinulosa was the highest, up to 46 times, accounting for 38.3% of the total frequency. (4) At least 30 compounds were detected by GC-MS, including 23 from A. spinulosa, 19 from A. metteniana, and 8 shared compounds such as γ-sitosterol, stigmastanol, 2-propenoic acid, 3-(4-methoxyphenyl)-, 2-ethylhexyl ester, nonanal, and other alkanes. The chemical compounds in leaves of A. spinulosa and A. metteniana were mainly hydrocarbons, followed by alcohols and aldehydes.   Conclusion  The larvae of P. viridifasciata have a strong ability to distinguish host plants from non-host plants, and can be attracted by host plants A. spinulosa and A. metteniana. Mixture of 3-Hexen-1-ol, (Z)- and nonanal can be used as attractants for P. viridifasciata. Ch, 2 fig. 4 tab. 38 ref.]