Induced volatiles in the interaction between soybean (Glycine max) and the Mexican soybean weevil (Rhyssomatus nigerrimus)

Abstract The present study analyzed the volatile compounds emitted by Glycine max (cv. FT-Cristalina-RCH) soybean plants: healthy plants and plants damaged mechanically or by the Mexican soybean weevil Rhyssomatus nigerrimus. The SPME method was used to compare the volatile profile of soybean plants in four different conditions. The volatile profile of G. max plants infested by R. nigerrimus was qualitatively and quantitatively different from that of healthy and mechanically damaged plants. Emission of 59 compounds was detected in the four treatments. Of these compounds, 19 were identified by comparison of the Kovats index, mass spectrum and retention times with those of synthetic standards. An increase in concentration of the volatiles (Z)-3-hexenyl acetate and the compound 1-octen-3-ol was observed when the soybean plants were mechanically damaged. The compounds mostly produced by the soybean plant during infestation by male and female R. nigerrimus were 1-octen-3-ol, 6-methyl-5-hepten-2-one, (E)-β-ocimene, salicylaldehyde, unknown 10, linalool, methyl salicylate, (Z)-8-dodecenyl acetate (ester 5), ketone 2 and geranyl acetone. Behavioral effects of the identified compounds during the insect-plant interaction and their conspecifics are discussed.摘要 本研究针对栽培品种FT-Cristalina-RCH的大豆（Glycine max）植株释放的挥发性化合物展开分析，受试植株分为健康植株、机械损伤植株以及受墨西哥大豆象鼻虫（Rhyssomatus nigerrimus）侵害植株三类。本研究采用固相微萃取（Solid Phase Microextraction, SPME）法，对比四种不同处理条件下大豆植株的挥发性成分谱。受墨西哥大豆象鼻虫侵害的大豆植株，其挥发性成分谱在定性与定量层面均与健康植株及机械损伤植株存在显著差异。四种处理组中共检测到59种挥发性化合物，其中19种可通过对比科瓦茨保留指数、质谱图与保留时间，并结合合成标准品完成定性鉴定。当大豆植株遭受机械损伤时，其释放的(Z)-3-己烯乙酸酯与1-辛烯-3-醇的浓度均出现上升。受雄性与雌性墨西哥大豆象鼻虫侵害时，大豆植株主要释放的挥发性化合物包括1-辛烯-3-醇、6-甲基-5-庚烯-2-酮、(E)-β-罗勒烯、水杨醛、未知物10、芳樟醇、水杨酸甲酯、(Z)-8-十二碳烯乙酸酯（酯5）、酮2以及香叶基丙酮。本研究还探讨了上述鉴定出的化合物在昆虫-植物互作以及昆虫同种个体间行为交互中发挥的作用。