Bukovinszky T, Gols R, Posthumus M A, Vet L E M, Van Lenteren J C
Department of Plant Sciences, Laboratory of Entomology, Wageningen University and Research Centre, 6700 EH Wageningen, The Netherlands.
J Chem Ecol. 2005 Mar;31(3):461-80. doi: 10.1007/s10886-005-2019-4.
Differences in allelochemistry of plants may influence their ability to attract parasitoids. We studied responses of Diadegma semiclausum (Hellén), a parasitoid of the diamondback moth (Plutella xylostella L.), to inter- and intraspecific variation in odor blends of crucifers and a non-crucifer species. Uninfested Brussels sprout (Brassica oleracea L. gemmifera), white mustard (Sinapis alba L.), a feral Brassica oleracea, and malting barley (Hordeum vulgare L.) were compared for their attractivity to D. semiclausum in a Y-tube bioassay. Odors from all plants were more attractive to the parasitoid than clean air. However, tested against each other, parasitoids preferred the volatile blend from the three cruciferous species over that of malting barley. Wasps also discriminated between uninfested crucifers: mustard was as attractive as feral B. oleracea, and both were more attractive than Brussels sprout. Attractivity of uninfested plants was compared with that of plants infested by larvae of the host P. xylostella. Host-infested mustard and Brussels sprout were more attractive than uninfested conspecifics. Interestingly, the volatile blends of uninfested white mustard and infested Brussels sprout were equally attractive. We also compared the volatile composition of different plant sources by collecting headspace samples and analysing them with GC-MS. Similarities of volatile profiles were determined by hierarchic clustering and non-metric scaling based on the Horn-index. Due to the absence of several compounds in its blend, the volatile profile of barley showed dissimilarities from blends of crucifers. The odor profile of white mustard was distinctly different from the two Brassicaceae. Feral Brassica oleracea odor profile was different from infested Brussels sprout, but showed overlap with uninfested Brussels sprout. Odor blends from infested and uninfested Brussels sprout were similar, and mainly quantitative differences were found. D. semiclausum appears to discriminate based on subtle differences in volatile composition of odor blends from infested and uninfested plants.
植物化感作用的差异可能会影响它们吸引寄生蜂的能力。我们研究了小菜蛾（Plutella xylostella L.）的寄生蜂半闭弯尾姬蜂（Diadegma semiclausum (Hellén)）对十字花科植物和一种非十字花科植物气味混合物种间和种内变异的反应。在Y型管生物测定中，比较了未受侵染的抱子甘蓝（Brassica oleracea L. gemmifera）、白芥（Sinapis alba L.）、野生甘蓝型油菜和麦芽大麦（Hordeum vulgare L.）对半闭弯尾姬蜂的吸引力。所有植物的气味对寄生蜂的吸引力都比清洁空气更大。然而，相互比较时，寄生蜂更喜欢三种十字花科植物的挥发性混合物，而不是麦芽大麦的。黄蜂也能区分未受侵染的十字花科植物：白芥和野生甘蓝型油菜的吸引力相当，且二者都比抱子甘蓝更具吸引力。将未受侵染植物的吸引力与被寄主小菜蛾幼虫侵染的植物的吸引力进行了比较。被寄主侵染的白芥和抱子甘蓝比未受侵染的同种植物更具吸引力。有趣的是，未受侵染的白芥和被侵染的抱子甘蓝的挥发性混合物同样具有吸引力。我们还通过收集顶空样品并用气相色谱-质谱联用仪（GC-MS）进行分析，比较了不同植物来源的挥发性成分。基于Horn指数，通过层次聚类和非度量缩放确定挥发性成分谱的相似性。由于其混合物中缺少几种化合物，大麦的挥发性成分谱与十字花科植物的混合物不同。白芥的气味谱与两种十字花科植物明显不同。野生甘蓝型油菜的气味谱与被侵染的抱子甘蓝不同，但与未受侵染的抱子甘蓝有重叠。被侵染和未受侵染的抱子甘蓝的气味混合物相似，主要是在数量上存在差异。半闭弯尾姬蜂似乎是根据被侵染和未受侵染植物气味混合物挥发性成分的细微差异来进行区分的。
