【作者】 邵淑霞；

【导师】 陈晓鸣；

【作者基本信息】 中国林业科学研究院 ， 生态学， 2013， 博士

【摘要】 角倍是角倍蚜Schlechtendalia chinensi（sBell）寄生在漆树科盐肤木Rhus chinensis Mill复叶叶翅上而形成的一种虫瘿，是角倍蚜与盐肤木之间相互作用、相互适应而达到的一种平衡，然而目前，有关两者之间协同进化的研究比较少。本文主要以角倍蚜、盐肤木以及角倍为研究对象，通过对角倍生长发育动态、寄主植物生理代谢变化动态、瘿内蚜虫种群动态的研究，初步弄清了角倍生长发育与蚜虫数量之间的关系、蚜虫种群密度与其翅型分化之间的关系、瘿内世代各蚜型在触角感器方面的差异、以及盐肤木对角倍蚜刺激的生理响应，为虫瘿生长发育影响因素及有翅蚜产生机制的研究奠定了一定的基础，同时，也为角倍蚜与其寄主植物盐肤木之间协同进化的研究提供了有力的证据。主要结论如下：（1）角倍生长发育及角倍蚜瘿内世代种群动态的研究研究发现，角倍的生长发育存在4个阶段：第一次缓慢生长期、快速生长期、第二次缓慢生长期和缩减期。角倍的体积和表面积于7月底才开始快速增长，10月期间达到最高值，其变化趋势与瘿内蚜虫种群数量的变化趋势比较一致。10月角倍成熟爆裂时，倍内蚜虫数量可由1头增至成千上万头。角倍蚜的种群动态变化较明显，干母虫型于5月下旬至6月上旬开始产第一代无翅干雌，7月初即出现第二代无翅干雌，8月底时，倍内即可见翅芽明显的第三代有翅干雌若蚜，但数量较少，不及蚜虫总数的1%。10月初，倍内开始出现有翅干雌的成蚜。角倍内蚜虫种群密度及拥挤度的变化可能引发了有翅蚜的产生。在所测的8个虫瘿形态指标中，虫瘿的体积最能反映干母的适应度。（2）角倍蚜瘿内世代各蚜型触角感器的超微结构研究本研究利用扫描电镜对角倍蚜各蚜型触角感器的超微结构、类型、分布及数量进行了比较分析。结果表明，角倍蚜的触角上具有毛形感器、原生感觉圈、感觉突及次生感觉圈4种类型的感器，但各蚜型触角感器的种类和数量均不同。各蚜型触角感器的差异可能与蚜虫的生境、取食、迁移及寄主选择等行为有关。（3）角倍形成过程中，寄主植物对蚜虫刺激的光合、营养和脱落酸的响应比较分析了角倍、有倍叶和无倍叶三组织中叶绿素、脱落酸和氨基酸3个生理指标的变化。研究表明，角倍含有叶绿素a，叶绿素b，虽然角倍的叶绿素含量明显低于叶片的叶绿素含量，叶绿素变化规律与寄主植物的叶片基本一致，说明角倍具有一定的光合作用能力，是一种变态叶。角倍中脱落酸含量显著低于寄主植物的叶片，在角倍形成过程中，角倍的脱落酸变化与寄主植物脱落酸变化基本一致，呈单峰曲线，脱落酸有阻遏赤霉酸及细胞分裂素促进生长的作用；与叶子的衰老、果实的脱落等有关。角倍中脱落酸含量低，可能是由于角倍蚜释放的某种物质抑制了角倍内脱落酸的合成，角倍中脱落酸含量低于叶片中脱落酸的含量，干扰了叶翅的正常生长，形成了变态叶，没有脱落酸的抑制，叶翅无节制的生长，所以形成了虫瘿的奇特形状。角倍中脱落酸含量上升是抑制虫瘿生长的信号，是角倍成熟先兆，这种信号传递给角倍蚜虫，使蚜虫产生有翅蚜，为虫瘿破裂而作迁飞准备。角倍，生长角倍的寄主植物叶片和没有生长角倍的寄主植物叶片的氨基酸组成相同，均含有17种相同的氨基酸，但各自所含氨基酸的数量不同，生长角倍的寄主植物叶片氨基酸含量高于没有生长角倍的寄主植物叶片的氨基酸含量，而角倍中氨基酸的含量明显低于叶片，这说明寄主植物受蚜虫刺激后，叶片的氨基酸含量增加，形成“营养源库”，再将营养分配给生长需求的角倍。这一结果支持“源库假说”。（4）角倍中一种炭疽菌病害初报在对角倍生长发育及倍内蚜虫种群动态的研究过程中，笔者从角倍中分离得到一种病原菌，描述了该病原菌对角倍的危害状况，并对该病原菌进行了形态学和分子生物学鉴定，确认该菌为胶孢炭疽菌Colletorichum gloeosporioides（Penz.）Sacc，分类上隶属于半知菌门Deuteromycotina、腔孢纲Coelomycetes、黑盘孢目Melanconiales、炭疽菌属Colletotrichum。更多还原

【Abstract】 Horned gallnut is induced by Schlechtendalia chinensis (Bell) on the leaflets of itsprimary host Rhus chinensis Mill, and is also the result of a close relationship between S.chinensis and its host plant R. Chinensis, and reflects their long-term coevolution. But thereis a few of researches about their coevolution relationship. This paper mainly regards S.Chinensis, R. Chinensis, and horned gallnut as the research object. By the studies about thedynamic growth of horned gallnut, physiological changes of R. Chinensis, clone dynamics ofS. Chinensis and their honeydew excretion, we have preliminarily understood the relationshipbetween gall development and aphids clone size, the relationship between aphid density andwing dimorphism, the differences of galling aphid in antennal sensilla and honeydew excretion,and R. Chinensis’ response to S. Chinensis’stimulation. This research have laid thegroundwork for future research on the mechanisms of gall formation and wing dimorphism,and also provided powerful evidence for coevolution researches between S. chinensis and R.Chinensis. The main conclusions are as follows:(1) The study on gall development and clone dynamics of the galling aphid S. chinensisWe found that: Gall-size changes occurred in four stages: a first slow growth period, a fastgrowth period, a second slow growth period and a growth reduction period. Gall volume andsurface area increased abruptly towards the end of July, peaking during October, in parallelwith an increase in aphid clone size, from one individual to more than10000aphids per gall.Clear changes were seen in the clone dynamics of S. chinensis. Fundatrix began to producefirst-generation apterous fundatrigenia during late May to early June. Second-generationapterous fundatrigenia appeared at the start of July. Alate fundatrigeniae with wing pads firstappeared at the end of August, but accounted for <1%of the individuals in the galls. Adultalate fundatrigeniae first appeared at the start of October. Abrupt changes in aphid density and crowding might trigger the induction of alate morphs in the galls. Of the eight gall propertiesthat we recorded, gall volume was the most accurate measure of gall fitness.(2) Comparison and analysis of the antennal sensilla of morphs of the galling aphidUsing scanning electron microscopy, we compared and analyzed the ultrastructure, type,distribution and number of antennal sensilla of morphs of the aphid S. chinensis. The resultsshowed that S. chinensis has four types of antennal sensillum: trichoid sensilla, primaryrhinaria, sensory projections and secondary rhinaria, which varied in their distribution andappearance on the antenna of the different morphs. We suggest that these differences detectedare related to the habitat of the particular morph, its main form of behavior (e.g. Feeding,migration, and host selection).(3) Host Plant photosynthetic, nutrition and ABA response to aphid stimulation duringhorned gallnut developmentWe studied the changes of amino acid, chlorophyll and abscisic acid in horned gallnuts(HG), leaves with galls (LWG) and leaves without galls (LNG) throughout the period of galldevelopment. The result showed that there were chlorophyll a and b in HG. Although thechlorophyll content in HG was obviously lower than that in leaves, both chlorophyll changregularities were basically the same. That showed HG had a certain capacity of photosynthesis,and was a kind of metamorphosed leaf.The chang of abscisic acid content in HG was a single-peak curve which was graduallyincreased and declined at the late stage of gall development. The abscisic acid content in HGwas obviously lower than that in leaves of R. Chinensis during the process of gall development.Abscisic acid have effects of inhibiting growth promotion induced by gibberellic acid andcytokinin, and is related to leaf senescence, fruit abscission etc. The low content of abscisicacid in HG was probably due to a substance which was released by S. Chinensis and thissubstance inhibited the abscisic acid synthesis in HG. The normal growth of leaf wing may beinterfered by the low content of abscisic acid in HG and form a metamorphosed leaf. Withoutthe inhibition of abscisic acid, leaf wing grew excessively, and finally formed the peculiar shape of gall. The increase of abscisic acid content in HG was a signal to suppress gall growth,and was also a portent of gall maturity. The signal may be transmitted to S. Chinensis, andhave an impact on the wing dimorphism which made preparation for their migration.The composition of amino acid in HG, LWG and LNG was the same, all containing17kinds of the same amino acid, but the content of them is significantly different. The amino acidcontent in galled leaves (LWG) was higher than that in ungalled leaves (LNG), and that inhorned gallnut (HG) was obviously the lowest. That showed that the amino acid content inleaves was increase after the host plant stimulated by aphids, and formed the nutrition sink forthe galls. This result support the " source-sink hypothesis".(4) A preliminary study on Colletorichum from horned gallnutWhen studied gall development and clone dynamics of the galling aphid, we isolated apathogenic fungus from horned gallnut. Its damage status and mycelium characters on gall andmydium are described, and its morphological and molecular biological characteristics wereidentified. The pathogenic fungi is Colletorichum gloeosporioides (Penz.) Sacc belongs toMelanconiales (Deuteromycotina: Coelomycetes).更多还原