植物介导下伊氏叶螨的竞争取代机制及两种害虫寄主适应性研究

发布时间：2017-12-28 09:22

本文关键词：植物介导下伊氏叶螨的竞争取代机制及两种害虫寄主适应性研究　出处：《西北农林科技大学》2015年博士论文　论文类型：学位论文

【摘要】：植物为植食性动物提供食物资源和空间资源,并在植食者之间的相互作用中发挥着不可替代的作用。当寄主植物被植食者取食时,植物对资源重新配置用于生长和防御,从而改变植物营养和防御物质的构成。这种由植食者诱导的改变不仅影响着植食者自身,还会对其他的植食者和天敌产生影响,从而影响植食者之间和植食者与天敌之间的相互作用关系,甚至还会改变群落的构成。伊氏叶螨是茄科植物的重要害虫。自从上个世纪后半叶入侵欧洲后逐渐取代了当地的二斑叶螨成为主要害虫。根据其生物学特性,我国东南部将是其可能的入侵之地。有关伊氏叶螨如何通过竞争取代二斑叶螨的内在机制尚不清楚。有研究表明伊氏叶螨能够抑制番茄的植物防御,从而促进其种群的增长并在局部范围内使其他害虫受益,而二斑叶螨能诱导番茄的植物防御并对其他害虫产生负面影响。但伊氏叶螨如何通过抑制植物防御与其他害虫相互作用、人为机械损伤(如打顶)对其影响如何、对寄主植物不同部位的取食喜好及其原因等问题还不清楚,而这些问题是揭示伊氏叶螨竞争取代土著叶螨的关键。基于此,本研究选用能够诱导植物防御的绿色型二斑叶螨和抑制植物防御的伊氏叶螨,首先以打顶为例研究了入侵害虫与土著害虫对机械损伤诱导的植物变化的敏感性;其次研究了空间隔离的两种叶螨之间的相互作用关系,分析了两种叶螨取食后植物抗逆物质多酚氧化酶(PPO)的变化;之后研究了不同情形下两种叶螨共同取食同一叶时的竞争关系并对两种叶螨的定殖行为进行了分析;最后以叶螨和蚜虫为例讨论了植食者对寄主植物的适应性以及温度的影响。综合各研究结果得到如下结论:一、二斑叶螨受到了番茄打顶的负面影响,繁殖率、存活率以及种群增长速率都显著降低。伊氏叶螨个体的适应性(存活率和繁殖率)不仅未受到番茄打顶的影响,而且打顶引起的番茄叶片的加速生长促进了伊氏叶螨的种群增长,即农事操作打顶对伊氏叶螨有利。二、伊氏叶螨诱导的植物防御物质多酚氧化酶PPO活性比二斑叶螨诱导的活性低、缓慢,且不受二斑叶螨取食的影响;而二斑叶螨对PPO活性的诱导受到伊氏叶螨的影响,伊氏叶螨的取食显著降低了二斑叶螨取食诱导的PPO活性。三、伊氏叶螨种群的环境最大容纳量是二斑叶螨的近三倍,种群增长速率显著高于二斑叶螨,其对寄主的选择偏好受初始种群数量的显著影响。四、两种叶螨之间的相互作用具有不对称性:因为伊氏叶螨取食抑制了植物防御所以对二斑叶螨有益,而二斑叶螨取食对伊氏叶螨没有影响;如有竞争者存在时,伊氏叶螨偏好利于其种群增长的叶片,而二斑叶螨则受到了伊氏叶螨的干扰,倾向于选择种群增长缓慢的叶片。五、两种叶螨的竞争关系取决于其所取食的叶片。当两种叶螨共同取食老叶或伊氏叶螨取食老叶而二斑叶螨取食嫩叶时,伊氏叶螨种群增长速率远远高于二斑叶螨并将最终取代二斑叶螨。六、建立了变幅变周期自由振动模型刻画叶螨和蚜虫种群时空动态,且许多昆虫都具有这种规律,表明该模型具有普遍意义。七、经长期驯化,二斑叶螨和桃蚜的寄主适应性显著提高,同时桃蚜的寄主适应性受到了温度的显著影响。总之,二斑叶螨对植物诱导抗性敏感,而伊氏叶螨对植物诱导抗性不敏感、种群增长快、环境容纳量更大、能够干扰二斑叶螨的定殖选择,并且在成熟叶片上具有明显的竞争优势,从而在一定程度上揭示了入侵害虫伊氏叶螨竞争取代欧洲土著二斑叶螨的内在机制,为植物诱导的植食者之间相互作用的理论提供了支持。同时温度对桃蚜寄主适应性的调节为蚜虫的季节性迁移提供了依据,验证了环境变化对植物-取食者之间选择压力的影响。
[Abstract]:Plants provide food and space resources for phytophagous animals, and play an irreplaceable role in the interaction of herbivers. When the host plant is fed by the herbivore, the plant reconfiguring the resources for growth and defense, thereby changing the composition of plant nutrition and defense substances. This change induced by herbivore not only affects the herbivore itself, but also affects other herbivores and natural enemies, thereby affecting the interaction between herbivore and herbivores and natural enemies, and even changing the composition of the community. Meroes mites are important pests of Solanaceae plant. Since the second half of the last century, the invasion of Europe has gradually replaced the local two leaf mite as the main pest. According to its biological characteristics, the southeastern part of our country will be a possible place of invasion. How about an internal mechanism of mite through competition instead of the two spotted spider mite is unclear. Studies have shown that they can inhibit mite of tomato plant defense, so as to promote its population growth and in the local scope to benefit other pests, and two spotted spider mite induced tomato plant defense and have a negative impact on other pests. But how's Mite by inhibiting plant defense and other insect interactions, artificial mechanical damage (such as topping) the influence of feeding preferences, how different parts of the host plant and the cause of the problem is not clear, and these problems is the key to reveal an mite mite competition instead of indigenous. Based on this, this study used green type can induce plant defense of the two spotted spider mite and suppression of plant defense's mite, first of all to mature as an example to study the sensitivity of invasive insects and pests of native vegetation changes induced by mechanical damage; followed by the study of the interaction between the two species of mites isolated space. Analysis of two species of mites after feeding plant polyphenol oxidase (PPO) material changes; after the study of two different cases of mite feeding competition between the common and the same leaf of two species of mites colonization was analyzed; finally the mites and aphids were discussed and adaptability predators on host plants and the influence of temperature. The results of the study were as follows: one or two. Spider mites were negatively affected by tomato topping, and their reproductive rate, survival rate and population growth rate were significantly reduced. An individual adaptability of mites (survival rate and reproductive rate) not only did not affect tomato topping and topping, tomato leaves caused by the acceleration of growth promoting the growth of Yi mite populations, namely farming operation topping on an advantageous leaf mites. Two, Yi mite induced plant defense substances polyphenol oxidase PPO activity than the two spotted spider mite induced low activity, slow, and is not affected by the two spotted spider mite feeding; and two spotted spider mite induced the activity of PPO is affected by meroes mites, mites feeding them significantly reduced the two spot mite feeding induced PPO activity. Three, Yi mite population environmental capacity is nearly three times the two spotted spider mite, the population growth rate was significantly higher than that of the two spotted spider mite, the preference of the host is affected by the initial population. Four, two species of mites interaction is asymmetric: because they inhibit mite feeding plant defense so beneficial to the two spotted spider mite, and two spotted spider mite Tetranychus evansi feeding had no effect on; if competitors exist, they mite preference conducive to leaf population growth, and the two spot it is an interference of mite mites, leaves tend to slow population growth. The competitive relationship between the five and two species of mites depends on the leaves they eat. When the two kinds of common feeding mites mites feeding an old leaves or old leaves and two spotted spider mite feeding leaves, an increase of mite population rate is far higher than the two spotted spider mite and will eventually replace the two spotted spider mite. Six, a variable amplitude and periodic free vibration model is established to characterize the temporal and spatial dynamics of spider mites and aphids. Many insects have this rule, indicating that this model has universal significance. Seven, after a long time of domestication, host adaptation of two spotted spider mite and aphid was significantly increased, while the host adaptability of Myzus persicae were affected by temperature. In short, the two spotted spider mite resistant plant and sensitive to induction, Trypanosoma mites on plant induced resistance is not sensitive, fast population growth, environmental capacity is bigger, can interfere with the two spotted spider mite colonization, and has obvious competitive advantage in mature leaves, thus to a certain extent reveal the mechanism of an invasive pest mite competition to replace the native two spotted spider mite, provides support for the induction of plant plant interactions between predators theory. At the same time, temperature regulation of Myzus persicae host adaptability for the seasonal migration of aphids to provide the basis, verify the influence between environment change on plant - feeding selection pressure.
【学位授予单位】：西北农林科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：S433

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