红色型和绿色型豌豆蚜种群演替的生态机制研究

The pea aphid is one of important pests on legume crops and forages, which include red and green color morphs. In recent years, the population of red pea aphid rises year by year. Because there is significant difference in the response to environmental conditions and virulence between the red and green pea aphid, the pea aphid population will break out and cause heavy losses once the changes in environmental conditions and crop varieties resistance loss. Biological resource competition and apparent competition are the hot focus in Ecology, and the competition mechanism is the core contents of biological succession as well. And now, it is not clear both in resource competition countermeasure and the influence regularity of temperature changes on resource competition in the two color morphs. Meanwhile, an opposite conclusion is existed about the apparent competition strategy in the two color morphs under the action of natural enemies. So the project is aim at the adaptive strategy in ambient temperature changes, the competition mechanism on food resources as well as the apparent competition strategy in natural enemies. In order to clear the ecological strategy and its change rules in two biotypes under the same food resources and common enemies, and to reveal the population dynamics and succession mechanism of two color morphs.

豌豆蚜是重要的豆科作物及牧草害虫。近年来，红色型豌豆蚜的种群数量所占比例在逐年上升。由于红色型和绿色型豌豆蚜对环境条件的反应及致害性存在显著差异，一旦环境条件变化及作物品种抗性丧失，会造成种群数量爆发成灾。生物间的资源竞争和似然竞争是生态学研究的热点问题，其竞争机制也是生物间演替的核心内容之一。但目前尚不清楚两种色型豌豆蚜的资源竞争对策以及温度变化对资源竞争的影响规律，对天敌作用下两种色型豌豆蚜的似然竞争策略也存在相反的结论。本课题将研究红色型和绿色型豌豆蚜对环境温度变化的适应对策，对食物资源的竞争机制以及在天敌作用下的似然竞争策略，明确两种色型豌豆蚜在相同食物资源及共同天敌作用下的生态对策及其变化规律，揭示两种色型豌豆蚜的种群动态及演替机制。

本项目研究了红色型和绿色型豌豆蚜在不同温度、光照、紫外线辐射等条件下的种群数量变化机制，探讨了两种色型豌豆蚜的种群间及种群内的竞争机制，研究了捕食性天敌瓢虫和寄生性天敌阿尔蚜茧蜂对两种色型豌豆蚜种群数量变化的影响规律，取得以下主要结论：（1）明确了2种色型豌豆蚜对温度、光照和紫外辐射等环境因素变化的适应对策。高温使2种色型豌豆蚜的死亡率上升，当温度升至32 ℃时，2种色型豌豆蚜均不能发育至成虫。红色型豌豆蚜在较低温度条件下适应性较强，而绿色型豌豆蚜更适合较高温度。短光照条件（4L:20D）能延长两种色型豌豆蚜的若蚜发育历期及成蚜寿命，降低若蚜存活率、繁殖力及生命表各项参数；长光照条件（22L:2D）能缩短两种色型豌豆蚜的若蚜发育历期及成蚜寿命，若蚜存活率高、繁殖力强；红色型豌豆蚜更适宜光周期10L:14D，而绿色型豌豆蚜更适宜光周期16L:8D。（2）掌握了紫外胁迫对2种色型豌豆蚜种群数量动态的影响规律。连续UV-B胁迫对两种色型处理时间越长，随着世代数增多，UV-B对豌豆蚜生长发育和繁殖抑制作用越强，种群数量增长越慢。在长期UV-B胁迫下，豌豆蚜主要依靠SOD清除体内有害自由基，两种色型之间红色型豌豆蚜对UV-B胁迫的抗性更强。（3）阐明了两种色型豌豆蚜对食物资源的竞争机制。两种色型豌豆蚜的种群间竞争不强，但存在较强的种群内竞争，随着种群密度的升高，两种色型豌豆蚜的存活率显著降低，寿命缩短，繁殖力下降。(4）探明了两种色型豌豆蚜在阿尔蚜茧蜂和瓢虫作用下的竞争对策。阿尔蚜茧蜂对绿色型豌豆蚜寄生率显著高于红色型豌豆蚜，对2龄若蚜的寄生率最高。多异瓢虫对两种色型豌豆蚜无明显的选择偏好, 异色瓢虫对红色型豌豆蚜具有一定的偏好性。研究成果对于豌豆蚜田间种群动态的监测预警、制定防治策略、培育抗蚜品种均具有重要的理论价值和应用前景。