【作者】 徐振；

【导师】 董双林；

【作者基本信息】 南京农业大学 ， 农业昆虫与害虫防治， 2010， 博士

【摘要】 人类活动大大强化了生物的进化压力,化学防治导致的害虫抗药性就是一个典型例子。杀虫剂胁迫可能对害虫性信息素通讯系统产生影响,而经过长期选择形成的害虫抗性品系的信息素通讯系统,与其敏感品系相比甚至会存在明显的分化。性信息素介导的昆虫雌雄个体间的求偶和交配,具有高度的敏感性和种特异性,因此作为一种重要的害虫防治途径,同时又是昆虫种群繁殖及种间生殖隔离的重要环节。研究农业害虫抗性品系与敏感品系间性信息素通讯系统的变化,有助于我们更加有效的利用昆虫性信息素来进行害虫防治,同时有利于我们了解在杀虫剂选择下害虫种群的分化过程。本论文以重要农业害虫小菜蛾为对象,对其阿维菌素和虫酰肼抗性品系及其敏感品系的性信息素通讯系统进行了比较研究,同时分析了亚致死剂量阿维菌素处理小菜蛾幼虫后对所得成虫信息素通讯系统的影响,主要结果如下：1小菜蛾抗阿维菌素品系,抗虫酰肼品系与敏感品系间性信息素通讯系统的差异求偶行为观察表明,抗感品系间雌虫的求偶节律没有显著差异,但两种抗性品系雌虫在求偶高峰期的求偶率显著低于敏感品系。对求偶高峰期雌虫腺体中性信息素的提取分析发现,两种抗性雌虫性信息素滴度都显著低于敏感雌虫,尤其是抗阿维菌素品系的雌虫,其性信息素两种主要组分的比例(Ald/Ac=1.59：8.41)较敏感品系(Ald/Ac=4.57：5.43)明显不同。雄虫对雌性性信息素二元混合物(Ald/Ac=1：1)的EAG反应试验证明,当性信息素剂量≥10ng时,两种抗性雄虫的反应显著高于敏感品系,但两种抗性品系间不存在差异；两种抗性品系对其他比例(Ald/Ac=1：9、3：7、7：3和9：1)性信息素混合物的EAG反应,也显著高于敏感品系。2小菜蛾抗阿维菌素品系、抗虫酰肼品系与敏感品系的风洞行为和交配选择性以雌蛾为信息素源对不同品系雄蛾进行的风洞行为反应试验证明,小菜蛾敏感品系、抗虫酰肼品系雌虫对三种品系雄虫的吸引能力都较高,彼此间没有显著差异,而抗阿维菌素品系雌虫对敏感品系、抗虫酰肼品系雄虫的引诱能力(达诱芯的比例分别为20.0和30.0%),都低于抗阿维菌素品系雄虫的35.0%,其中敏感品系与抗阿维菌素品系间存在显著差异。进一步的交配选择性试验表明,敏感品系和抗虫酰肼品系间存在同征交配现象；敏感品系和抗阿维菌素品系组合中,无论抗性还是敏感品系都倾向于和敏感品系交配；而在抗虫酰肼和抗阿维菌素品系组合中,两种雄虫都倾向于和抗虫酰肼品系雌虫交配。可见,抗阿维菌素品系雌虫性信息素组分间比例的明显变化,影响了雌虫对雄虫的吸引力,并进而降低其交配机会。这一结果对基于抗性基因稀释的害虫“庇护所”抗药性治理策略的正确实施,以及高效利用性信息素进行害虫预测和防治,均具有重要的指导意义。3小菜蛾抗阿维菌素品系与敏感品系杂交F1代的性信息素通讯系统敏感品系和抗阿维菌素品系的正反交F1代Z1(敏感雌虫×抗性雄虫)和Z2(敏感雄虫×抗性雌虫)雌虫的求偶节律和两个亲本类似,但雌虫暗期的求偶率、性信息素组分Z11-16:Ald的滴度、以及雄蛾对不同剂量性信息素混合物(Z11-16：Ald和Z11-16:Ac=1:1)的EAG反应均有明显变化,表现为介于两亲本之间,且具有明显的母本偏向性；雌虫的另一性信息素组分Z11-16：Ac的滴度在Z1、Z2和抗性品系间相似,均显著低于敏感品系。进一步对自交和回交后代等进行分析,有望阐明抗感品系间性信息素通讯系统差异的遗传机制。4亚致死剂量的阿维菌素处理幼虫对小菜蛾性信息素的影响亚致死剂量阿维菌素处理敏感品系小菜蛾三龄幼虫,显著延长了幼虫到蛹的发育时间并降低了蛹重。试虫羽化后,处理雌蛾高峰期的求偶率显著低于对照雌蛾；与对照雌蛾相比,处理雌蛾两种性信息素组分(尤其是Z11-16:Ald)的滴度显著减少,但两组分(Z11-16：Ald和Z11-16：Ac)间的比例没有显著差异。亚致死剂量的阿维菌素处理后,雄虫对不同剂量的雌性性信息素二元混合物的EAG反应增强,当处理剂量为1ng-100ng时达到显著水平；处理剂量在1000ng时,处理组仍然高于对照组,但差异不显著。对不同比例的性信息二元素混合物的EAG反应,处理组也都高于对照组,且当混合物比例(Z11-16：Ald/Z11-16：Ac)为9：1、5：5、3：7时,差异达到显著水平。因此,亚致死剂量处理类似于抗药性品系的情况,即抑制了雌虫性信息素的合成,而提高了雄虫对雌性信息素的电生理反应。抗阿维菌素品系和亚致死剂量阿维菌素处理后,引起小菜蛾性信息素通讯系统类似的变化,其中机制有待进一步研究。更多还原

【Abstract】 Human activities greatly speed up the evolutionary process of many animal species, and one best known example in insect is the the occurrence of insecticide resistance. Insecticide employment may affect the sex pheromone communication systems in pest, along with the evolution of pest resistance to insecticiede. With the high sensitivity and species-specificity, insect sex pheromone communication plays the key role in the reproduction behavior and has been used in pest control and population forecasting. Studes of the changes of sex pheromone communication system between resistant and susceptible pests is helpful for us to control pest more effectively with sex pheromone and to understand the process of speciation. This study comparaed the sex pheromone communication systems of tebufenozid resistant, abamectin resistant and their sussceptible strain in diamondback moth, and investigated the effects of larva treatment with sublethal dose abamectin on the sex pheromone communication system of survival moths. The main results were as following.1. Differences of sex pheromone communication systems in abamectin, tebufenozide resistant and sussceptible strain in diamondback mothCalling behavior of female moths showed that there was no difference in calling rhythm between two resistant and sussceptable females, while the calling percentages of resistant females were much lower than that of the sussceptible females. Analysis of sex pheromone showed that resistant females produced significantly less amounts of sex pheromone, compared with susceptible moths. More impotantly, the ratio of two major pheromone components (Ald/Ac) in Aba-R females was 1.6:8.4, much different from susceptible females (Ald/Ac=4.5:5.5). For the male side, resistant males showed significantly higher EAG responsiveness to female binary sex pheromone mixture (Ald/Ac=1:1) at the dose==1 Ong, and there was no difference between two resistant strains. Resistant males also showed higher EAG response to female binary sex pheromone mixture with ratio 1:9,3:7,7:3 and 9:1 (Ald/Ac) than sussceptible males.2. Wind tunnel and mating choice experiment in abamectin, tebufenozide resistant and susceptible strainWind tunnel experiment indicated that both susceptible and tebufenozide resistant female remaind high attractiveness to three males, with no difference among males of three strains. However, abamectin resistant females suffered low attractiveness to susceptible and tebufenozide resistant males (source contact percentages were 20% and 30%, respectively), lower than abamectin male (35%). The mating choice experiment confirmed that assosiative mating occur between susceptible and tebufenozide resistant strain; however, in susceptible and abamectin resistant strain combination, males of both strains tended to mate with suscaptible female; similarly two resistant male tended to mate with tebufenozide resistant female in abamectin and tebufenozide resistant strains combination. All the results suggest that abamectin female, in which the ratio of two major sex pheromone components was greatly changed, suffer low attractiveness to males and consequently low mating chances. This finding would be very important to the empoyments of’refuge strategy’in pest resistance management, and to the use of insect sex pheromone in pest control.3. Study of sex pheromone communication systems in hybrid F1 of abamectin resistant and susceptible strainThe F1 hybrid offspring Z1 (S(?)×R(?)) and Z2 (R(?)×S (?)) showed similar calling rhythm with their parents. However, the calling percentage and titer of pheromone Z11-16:Ald in females and male’s EAG responsiveness to the bianary pheromone mixture (Ald/Ac=1:1) at different dosages were all between those of two parents, and closer to the mother’s. Another pheromone component Z11-16:Ac was about the same among Z1, Z2 and the resistant strain, but sinificantly higher in the sucsseptible strain. The further analysis of offsprings of Z1×Z2 and the backcrosses will be requried to elucidate the genetics of the insecticide associated changes in sex pheromone communication system in the diamondback moth. 4. Sublethal effect of abamectin on sex pheromone communication systems in susceptible diamondback mothAbamectin treatment with sublethal dose not only extended the larva development and reduced pupa weight, but also affacted the sex pheromone communication system of the survival adults. Calling percentage of survival females reared from larvae treated with sublethal dose of abamectin was significantly lower than that of the control. In agreement, the titers of sex pheromone of treated females were reduced compared with the control females, especially the Z11-16:Ald component. The component ratio (Ald/Ac) was not significant different between treated and control moths. Treatment of larva with sublethal dose abamectin also significantly raised EAG response of males to female binary sex pheromone mixture dosed 1-100ng and at the ratio of 1:1 (Ald/Ac). To other ratioes of the binary sex pheromone mixture (Ald/Ac=9:1,5:5 and 3:7), treated males also showed significantly higher EAG response than control males. The influences on sex pheromone communication system by abamectin of sublethal dose and by the abamectin resistance were very similar, the mechanisms underlying which deservs to be explored.更多还原