【摘要】 棉铃虫Helicoverpa armigera和烟青虫H.assulta属于可同域发生的近缘种昆虫,通过产生比例相反的两种性信息素化合物———顺9-十六碳烯醛和顺11-十六碳烯醛维持种间生殖隔离。本研究应用外源不饱和脂肪醇及乙酸酯在棉铃虫和烟青虫性信息素腺体进行在体转化,利用气相色谱法分析转化产物,从酶学角度探讨了上述两近缘种昆虫性信息素腺体组分差异的形成原因。实验结果表明,两种昆虫信息素腺体表皮伯醇氧化酶对外源顺9-十六碳烯醇、顺11-十六碳烯醇和反10-十六碳烯醇无催化专一性,说明末端氧化过程对于醛类性信息素组分特定比例的形成不起作用。棉铃虫性信息素腺体组织具有较高的乙酸酯酶活性,可水解外源乙酸酯,但烟青虫性信息素腺体乙酸酯酶活性很低。这些发现对于进一步了解两种昆虫的生殖隔离机制有重要参考价值。更多还原

【Abstract】 Closely related species Helicoverpa armigera and H.assulta are two key crop pests sympatrically occurred in and around China.They use opposite ratios of cis-11-hexadecenal and cis-9-hexadecenal as their sex attractant pheromone components to maintain the interspecific reproductive isolation.Besides such difference in pheromone components,the acetate compositions in sex pheromone glands of the two species are also significantly different.In order to understand the biosynthetic mechanism resulting in the different compound compositions in pheromone glands of the two species,we topically applied unsaturated exogenous fatty alcohol and acetate precursors to the pheromone glands of H.armigera and H.assulta and monitored their conversion with gas chromatography analysis.The results showed that the gland oxidases had no substrate specificity to the exogenous cis-11-hexadecenol,cis-9-hexadecenol and trans-10-hexadecenol,and therefore the corresponding erminal oxidation reaction did not affect the formation of the specific sex pheromone blend ratio in the two species.Significantly higher esterase acitivity was found in the pheromone gland of H.armigera than that in the pheromone gland of H.assulta.These discoveries would be useful to fully elucidate isolation mechanisms of the two moth species.更多还原