川滇桤木气味对云南切梢小蠹繁殖机能的影响与评价

Volatile infochemcials of non-host plants involve the multiple behavioral manipulation of pests. So far, however, no information is available regarding reproduction decline of these pests. Our preliminarily studies showed that volatiles of non-host plants cause the reproduction decline of Yunnan shoot borer, Tomicus yunnanensis, which is one of the most destructive beetles in southwestern China. Unfortunately, the physiologically active compounds are not identified and the decline mechanism remains to be elucidated. Here, the project will conduct a series of experiments by using of Alnus ferdinandi-coburgii as the best stress materials. The aims is test the active odor compounds with the ability to disturb the reproduction of T. yunnanensis, and to investigate the effects of these active compounds on the reproductive organs, fecundity, postembryonic development, yolk protein contents, oocyte apoptosis, sperm quality, etc.. According the interference index of population control, we also assess the pest population changes on basis of reproduction decline and offspring numbers, respectively. The results will illustrate the intrinsic cause of population decline of T. yunnanensis that is suppress by non-host odors at the reproduction levels. The project will provide a theoretical context for designing mixed forest and reforming artificial forest, and are beneficial to reveal novel pest control strategies.

非寄主气味可调控害虫多种行为，但能否直接引起害虫繁殖机能衰退一直未见报道。前期研究发现非寄主气味物质干扰导致云南切梢小蠹（Tomicus yunnanensis）繁殖机能衰退，进而减少产卵，但是尚不清楚何种气味物质诱发繁殖机能衰退，也不知道影响衰退的机理。据此，本项目拟采用前期筛选出干扰效果最好的非寄主植物川滇桤木为材料，研究活性气味物质作为干扰因子影响云南切梢小蠹的生殖器官、产卵、胚后发育、卵黄蛋白合成、卵细胞凋亡，精子品质等，再通过重构种群趋势指数模型，从害虫繁殖机能衰退和胚后生长发育角度定性定量地评价非寄主植物调控小蠹虫种群数量的机制，为混交林营造和人工林的后续改造控制云南切梢小蠹的危害提供理论依据，为害虫调控提供新技术和新方法。

降低小蠹虫种群数量常被视作一种强健的森林生态调控措施，而用非寄主植物气味有其不可替代的重要性，特别是危害习性特殊的切梢小蠹。研究以云南切梢小蠹非寄主植物—川滇桤木为对象，筛选活性气味成分，确定其对云南切梢小蠹繁殖机能的影响，并拓展云南切梢小蠹诱捕和干扰化合物的研究。结果表明：（1）川滇桤木气味成分有45种，其中(Z)-4-己烯-1-醇、反-2-已烯-1-醇、4-烯丙基苯甲醚、α-蒎烯和对乙基苯乙酮具有电生理活性，且有趋避功能，对乙基苯乙酮趋避效果最佳。（2）活性气味干扰后，云南切梢小蠹卵巢的外部形态未发生变化，但其卵巢体积出现萎缩，卵黄蛋白含量下降，化合物β-蒎烯、反-2-已烯-1-醇、(Z)-4-己烯-1-醇、对乙基苯乙酮和4-烯丙基苯甲醚的干扰效果最好。（3）对于胚后发育，活性气味干扰未降低云南切梢小蠹的产卵量，但雌成虫主坑道、幼虫子坑道长度有不同程度的增加，各龄幼虫体长和体重亦有增加，(Z)-4-己烯-1-醇、反-2-已烯-1-醇、4-烯丙基苯甲醚增加趋势明显。（4）云南松不同受害阶段的挥发物有明显分化，α-蒎烯、4-烯丙基苯甲醚、3-蒈烯、γ-异松油烯、2-侧柏烯具电生理活性，且卵巢成熟度影响云南切梢小蠹对化合物的响应，但对云南切梢小蠹的胚后发育影响不一。（5）云南切梢小蠹幼虫有3个龄数，表皮碳氢化合物2,6,11-三甲基-十二烷、正二十三烷、正二十五烷可作为龄数标示物。成虫的颚须和唇须顶端着生数量不等的嗅觉和味觉感器，意味着云南切梢小蠹能够对寄主和配偶进行近距离识别定位。