【作者】 赵飞；

【导师】 马春森；

【作者基本信息】 中国农业科学院 ， 作物生态学， 2014， 博士

【摘要】 本研究通过模拟麦长管蚜世代内经历气候变暖三大特征：短时高温、持续热天、持续热天夜间温度升高，以及世代间经历高温天频率变化，研究了高温历史经历对昆虫耐热性、生活史性状的即时和迟滞效应，以及最终的种群动态后果。所得主要结论如下：1.证实阶段基底耐热性最高并不意味着短时高温后的迟滞响应表现最好。前期热锻炼不能进一步提高基底耐热性最高的3-4龄若蚜高温存活，较长时间的热锻炼对其耐热性还产生了负面影响；而前期热锻炼对于基底耐热性较低的低龄若蚜和成蚜高温存活存在正向效应，但热锻炼持续时间延长效果下降；短时高温后的生活史迟滞效应因考察性状不同而存在差异。1龄和4龄若蚜短时高温对若蚜发育速率的影响较大，热激2-3龄若蚜对发育速率的抑制较小；成蚜寿命和繁殖则主要受前期热经历的剂量影响，而与热激阶段无关。总体上看，热激剂量和热激作用阶段对麦长管蚜种群参数都有显著影响。2.与若蚜晚期高温相比，若蚜早期或成虫期经历持续高温产生了更为显著的种群后果。出人意料地，高温对若蚜发育历期主要由1龄若蚜是否经历高温所决定，与高温持续天数无关。若蚜的存活由早期1龄若蚜受热和高温持续时间共同决定。成虫性状表现则主要受高温持续时间影响。但从1龄若蚜开始的早期高温对麦长管蚜种群产生了显著地筛选作用，4-6天的高温淘汰掉大量不耐热个体，存活下来的成蚜表现与未受热个体相当。总体上看，若蚜早期和成蚜期的持续高温对种群参数的影响相当。而若蚜后期持续高温经历的种群响应显著好于若蚜早期和成蚜期。3.证实与高温天组合的夜间变暖能够产生更显著的生物效应。除若蚜后期没有显著响应外，若蚜早期、全若期和全世代热天夜间温度升高均显著加速了若蚜发育。与恒温条件相比，高温天夜间温度升高将发育最适温度提高3度。而整个若蚜生长期经历高温天夜间变暖可导致若蚜存活的线性降低，虽然这时的夜间温度变化尚处于麦长管蚜的适宜存活范围。总体上看，除若蚜前期夜间变暖的种群效应完全被白天高温所致的负面影响掩盖外，麦长管蚜若蚜后期、全若期以及全世代夜间温度升高均能显著恶化高温天导致的种群下降。4.证实母代高温经历会产生显著的跨代后续效应。母代高温通过抑制子代发育，降低子代存活，减少了种群的内禀增长率。母代高频高温的经历也可显著增加子代性状的变异度。总体上看，子代正常温度恢复甚至补偿了母代高温对子代生活史性状的负面影响；子代高温加剧了母代高温对种群的负面效应。更多还原

【Abstract】 By simulating temperature experiences of climate warming: short-time heat exposure, persistenthot days or night warming on hot days within generation, and the altered frequency of hot days inmaternal generation of Sitobion avenae, we investigated the immediate and time-lagged effects of heatstress experiences on the thermal tolerance and life history traits, as well as the consequence ofpopulation dynamics in S. avenae. The main conclusions are as follows:(1) Heat shock at the age with the greatest heat resistance does not mean that there are lessthermal time-lagged effects on other life history traits and population dynamics. The3rd-and4th-instars of S. avenae have the highest upper thermal tolerance. However, they were least able toacclimate (CTmax) in response to high temperatures, suggesting a potential trade-off between basaltolerance and the hardening ability to thermal tolerance. In addition, the time-lagged effects of heatshock at different ages may be trait-dependent. There were significant differences of nymphaldevelopmental times between heat exposure treatments at different age. The most inhibiting effects ondevelopmental time were observed at the first and fourth instars nymphs. But adult traits were affectedmainly by the duration of brief heat exposure. Further, the extent of population parameters reduceddepended on not only the duration of heat exposure but also the age exposed to heat.(2) Continuous hot days occurred at the early stage of nymphs or adult stage play moreimportant roles in population consequences than those occurred at the later stage of nymphs.Effect of high temperatures on nymph duration depended crucially on whether1st-instar stageexperienced hot days. And adult traits were determined largely by duration of hot days. However,nymphal survival depended on both1st-instar stage experienced hot days and duration of hot days.Overall, Continuous hot days occurred at the early stage of nymphs or adult stage play more importantroles in population consequences than those occurred at the later stage of nymphs.(3) Changes of these moderate nighttime temperatures have much biological impact whencombined with hot days. The development rates of nymphs increased with night warming on hot daysduring early or whole stage of nymph and a generation, although the increase of nighttime temperatureduring later stage of nymph did not significantly affect developmental rate. When compared toexpectations based on constant temperatures, night warming raised the optimum temperature fordevelopment by3°C, in contrast to results from experiments where temperature variability was alteredsymmetrically or in a parallel manner. Night warming experiences in whole stage of nymph alsoreduced linearly aphid survival under heat despite of temperatures shifting within a moderate range.Overall, night warming exacerbated the detrimental effects of hot days on the intrinsic rate ofpopulation increase except for any effects of night warming during early stage of nymph beingoverwhelmed by negative impacts of daytime high temperatures.(4) Maternal temperature has significant effects on population performance of offspringreared under high developmental temperature. Maternal temperature experience under continuous hot days affected negatively not only the development and survival of nymph exposed to highfluctuating temperature, but also the prereproductive time and the adult proportion of immediatelybreeding of offspring reared under22℃constant temperature. In addition, maternal high temperatureexperience (continuous hot days or frequent hot days) also affected profoundly fecundity of offspringunder normal fluctuating temperature. Further, both of two maternal patterns of hot days increased thedevelopmental variation of offspring. Although maternal experience of frequent hot days also increasedthe variation of adult traits, the least variation of offspring was observed when mothers were rearedunder continuous hot days. Overall, mediate temperatures of offspring might offset the negative effectsof maternal high temperature experience on population performance. However, maternal hightemperature condition can deteriorated further population consequence of offspring by50%if progenywas continued to be reared under high temperature condition.更多还原