【作者】 丛林；

【导师】 郭建英；

【作者基本信息】 中国农业科学院 ， 生物安全， 2010， 硕士

【摘要】 烟粉虱Bemisia tabaci (Gennadius),属同翅目,粉虱科,广泛分布于热带、亚热带及其相邻温带地区的90多个国家和地区,其主要通过口器吸取植物汁液、传播植物病毒、导致植物生理异常等方法对植物造成危害。B型烟粉虱自上世纪90年代中后期传入后,迅速扩散并在很多地方爆发成灾,对我国农业生产造成严重损失。作为一种成功入侵的害虫,B型烟粉虱的入侵机制已成为国内外研究热点。以往研究表明,其对高温的适应力是其成功入侵和扩张的关键因素之一。在全球变暖的趋势下,B型烟粉虱以其耐热性强的特点,将在对其他物种的竞争取代中占有优势。为了探明B型烟粉虱对高温胁迫的响应,本研究通过比较适温和高温胁迫条件下B型烟粉虱的种群动态、性比以及繁殖力,观察高温胁迫对其求偶和交配行为的影响,研究卵期不同时间和温度热激对烟粉虱生殖力的效应,以期明确高温胁迫对B型烟粉虱种群性比的影响及其生殖和行为机制,并为B型烟粉虱的监测、预警和治理提供理论依据。主要结果如下:1.高温胁迫对B型烟粉虱发育、种群动态和繁殖影响的连代效应通过在室内27、31、35、37℃条件下连续饲养5代,观测B型烟粉虱的卵孵化率、种群动态、含菌体缺失率及缺失个体羽化率、存活率、后代性比、雌虫繁殖力等指标,明确高温胁迫对其后代性比的影响。结果表明,不同的饲养温度和代数对上述指标有显著影响。种群动态和性比在不同温度处理和世代间具有显著差异。随着温度的升高和代数的增加,种群适合度降低。卵孵化率由27℃(对照)的98.9%,下降至35℃F5代的52.3%;35℃条件下,第4~5代由卵发育至成虫的存活率显著降低;F4代和F5代的发育速率减慢;在31℃饲养F4代时出现含菌体缺失;且在在35℃条件下,含菌体缺失率由0.3%上升至6.8%,但含菌体缺失率间差异不显著。随着处理温度的增高,雌成虫产卵前期缩短,寿命和产卵量均降低。2.高温条件下B型烟粉虱的求偶交配行为观测采用微距摄像法连续观察48h,比较适温(27℃)和高温胁迫(31℃)条件下B型烟粉虱的求偶和交配行为,包括搜索时间、求偶时间、交配时间、交配时间间隔、交配次数等。结果表明,与27℃对照相比,31℃条件下B型烟粉虱的交配次数显著减少,由27℃的3.4次减为31℃的2.6次;第一次交配的搜索时间和交配时间显著缩短,分别降低为对照的48%和56%;求偶时间也较短,但差异不显著;第二次交配的交配时间显著缩短为对照的74%,搜寻和求偶时间差异不显著;两次交配的间隔时间较长,但差异不显著。3.卵期短时高温暴露对B型烟粉虱存活和繁殖特性的影响对B型烟粉虱卵进行不同高温(39℃和41℃)、不同时间(1 h、2 h和4 h)的短时高温暴露处理,观察其存活、成虫性比和繁殖特性的变化。未受高温暴露的对照相比,卵期在41℃暴露1 h和4 h烟粉虱的存活率显著降低;卵期在41℃暴露1 h后烟粉虱的雌虫比例为61.3%;烟粉虱雌成虫寿命显著提高,产卵前期缩短。羽化雌虫的产卵节律和成虫生存曲线发生显著变化。4.总结与27℃处理的对照相比,在31℃和35℃条件下连续饲养若干代,B型烟粉虱的种群适合度(卵孵化率,存活率,发育速率,含菌体缺失率)具有不同程度的下降。31℃条件下B型烟粉虱的交配次数显著减少,交配时间显著缩短。高温和热激处理均可降低其产卵前期,并连续高温饲养缩短其寿命和降低其产卵量,而短时热激有利于雌虫寿命的延长和产卵量的上升。更多还原

【Abstract】 Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), distributes widely in over 90 countries and regions in tropical, subtropical and temperate areas. Damages of B. tabaci to host plants include direct feed on plant phloem sap, transmit plant viruses, and cause physiological disorder of plants. After the introduction of B. tabaci B-biotype into China in 1990s, it has spread rapidly and broken out in many provinces, causing severe economic lost in agriculture. Many former studies show that the adaptability of B. tabaci B-biotype to high temperature stress is one of the key mechanisms of its successful invasion and expansion throughout the world. Under the trend of global warming, the tolerance of B. tabaci B-biotype to high temperature stress could make it dominate in the competition with and replacement of other species. This stdudy aims to: (1) compare the population dynamics, sex ratio and fecundity of B. tabaci B-biotype under optimal and high temperatures, (2) compares its courtship and copulation behavior under optimal and high temperatures, (3) compare the fecundity of B. tabaci after short-term exposure of its eggs to high temperatures. The main results are as follows:1. Development, population dynamic and fecundity of B. tabaci B-biotype under high temperatures for five successive generationsEgg hatching rate, population dynamic, bacteriome-absent rate, survival rate of bacteriome-absent individuals, adult sex ratio, and fecundity of B. tabaci B-biotype were observed for five successive generations at 27, 31, 35, 37℃. The results showed that the factors of temperature and generation have significant impacts on the above indices. Population dynamics and sex ratios differed significantly among temperatures and generations. The fitness of B. tabaci populations decreased with the increasing temperatures and generations., Egg hatching rate dropped from 98.9% at 27℃(control) to 52.3% at 35℃for the fifth generation. The survival rate decreased signigicantly and the development slowered significantly from egg to newly eclosed adult at 35℃for the fourth and fifth generation than those at 27℃. Bacteriome-absent offspring were observed in the fourth and fifth generations at 31℃, and from the first generation and on at 35℃with a rate increasing from 0.3% to 6.8%. The survival rates of the bacteriome-absent offspring at different treatments did not differ significantly. For the female adult, its pre-oviposition period and longeivity were shortened, and the fecundity was lower with the increasing temperatures.2. Courtship and copulate behavior of B. tabaci B-biotype under different temperaturesUsing the video camera recording method, the courtship and copulate behavior of B. tabaci B-biotype under 27 and 31℃were recorded for 48h.. Searching period, courtship duration, copulation duration, copulation interval, and copulation frequency were calculated after playing back the records. The results indicated that the average copulation frequency of B. tabaci mate was 2.6 times at 31℃, which was significantly less than that at 27℃(3.4 times). The searching period and copulation duration during the first copulation process were shortened by 48% and 56% at 31℃than at 27℃. The courtship duration at 31℃was also shortened at an insignificant level than at 27℃. For the second copulation process, the copulation duration was shortened by 74% at 31℃than at 27℃. But the searching period, courtship duration and courtship interval did not differ significantly between 27℃and 31℃.3. Effects of different exposure time and high temperature on the survival and fecundityTo reveal the reactions of B. tabaci B-biotype to heat stress, effects of short-term (1 h, 2 h and 4 h) exposure of B. tabaci eggs to high temperature (39℃and 41℃) on the survival and fecundity were studied. Survival rates after exposure to 41℃for 1 h and 4 h were significantly lower. Female ratio of B. tabaci after exposure to 41℃for 1 hour was 61.3%.The longevity prolonged and the pre-oviposition period shortened. The oviposition rhythms and age-specific adult survival rates change. These results showed that short-term exposure of B. tabaci to high temperature at egg stage decreased its survival rate, whereas increased its fecundity.4. ConclusionComparing with the control at 27℃, the fitness of B. tabaci B-biotype decreased to some extents after successive rearing atr 31℃and 35℃for 1 to 5 generations, regarding the indices of egg hatching rate, survival, development and bacteriome-absent rate. The copulation frequency and copulation duration shortened at 31℃. The pre-oviposition periods of B. tabaci decreased under successive rearing under continous high temperatures or under short-term high temperature exposure weres shorten, and the longevity and fecundity of female adults were decreased uner successive rearing under continous high temperatures, but risen under short-term high temperature exposure更多还原