【作者】 蔡凤环；

【导师】 赵惠燕；

【作者基本信息】 西北农林科技大学 ， 农业昆虫与害虫防治， 2003， 硕士

【摘要】 麦长管蚜（Macrosiphum avenae）属同翅目（Homoptera）蚜科（Aphididae），世界各地均有分布。在我国，麦长管蚜是禾谷类作物上的重要经济害虫，并能传播大麦黄矮病毒病（BYDV）。特别是干旱年份小麦穗期的主要害虫，产量损失一般达15-30％，严重年份甚至达60％以上。 在环境条件和化学农药、小麦品种等人为条件的强大选择压力下，麦长管蚜种群发生了较大的遗传变异。本研究采用两种多位点遗传标记（随机扩增RAPD-PCR和微卫星引物PCR）方法和两种遗传多样性指标（基因多样度和多态位点率），还采用遗传距离、相似性指数和聚类分析等统计分析方法作为数据分析处理方法。同时，对应用多位点标记以及统计分析中的问题进行了讨论。 结果表明： 1、根据分子量Mrker（EcoR₁-HindⅢ digest Lambda DNA），麦长管蚜基因组DNA的大小在21kb左右。 2、通过对影响RAPD扩增的各因素（如：模板浓度）和影响微卫星引物扩增的各因素（如：微卫星引物扩增的引物退火温度）筛选与分析，建立了稳定性和重复性都很好的最适反应体系。 3、应用多态位点率和基因多样度两种遗传多样性指标对不同麦长管蚜地理种群的随机引物扩增结果进行分析，表明群体内的遗传变异小于群体间的遗传变异，除了新疆这个春麦区麦长管蚜种群外，其他7个种群表现出南方种群DNA变异普遍比北方种群变异小，进而推测可能与各地域的气候条件有关，并且主要是由于温度的选择压力造成的。 4、8个种群间的遗传距离值（0.034-0.136）在Ayala（1979）所规定的地理种群遗传距离（0.031±0.007）和亚种遗传距离（0.23±0.016）之间，由此可见在不同地理区域生活的麦长管蚜种群的分化仅在种群水平上，未达到亚种水平的分化。 5、微卫星扩增结果的聚类分析说明：麦长管蚜种群的遗传变异差异明显，不同种群间呈现出丰富的DNA多态性，新疆这个唯一的春麦区麦长管蚜种群与其他7个冬麦区麦长管蚜种群DNA变异显著，正向亚种变异进化。8个种群的基因遗传变异呈现出以我国从东南到西北三阶梯地形梯度分布的格局，说明海洋气流和我国的地形造成了我国气候的多样性，从而影响到麦长管蚜地理种群的遗传变异。山东种群、安徽种群、河北种群、北京种群为第一阶梯，山西种群、四川种群、陕西种群为第二阶梯，新疆种群为第三阶梯。其中第一和第二阶梯麦长管蚜的遗传交流较大，从而显示出两阶梯种群DNA变异小于与新疆种群DNA变异;而新疆由于地理、温度等环境条件和种植制度等人为条件隔离，造成了与前两阶梯种群DNA遗传变异显著。同一阶梯的麦长管蚜种群由于气候条件和我国地形的相似性，再加_<sub>仁种群间的基因遗传漂流，从而造成了种群间的遗传变异的相似性较大。更多还原

【Abstract】 Macrosiphum avenae (Homoptera: Aphididae), is one of the most important pests to cereal crop, distributing world-wide. And also it is an efficient vector of several plants virus, what is more important, can spread barley yellow dwarf virus (BYDV). It is the main pest of wheat, especially in dry period, which result in decreasing of yield and quality of wheat.The powerful heterogenic for population differentiation and genetic variation strength its adaptability to variable environment, M.avenae adapted to the nature condition and it also resulted in the heredity variation of M.avenae populations. This study combined the population ecology with molecular biology.Two multilocus genetic markers (RAPD-PCR and SPRS-PCR) as well as two genetic diversity index (gene diversity index and polymorphic rate of loci) and various statistical analysis were used to detect and analysis the geographic population differention of M.avenae, such as heredity instance, likeness index and clustering analyzing. At the same time, the study discussed the problem of using multi-sites markers and statistics analyzing. The main result as follows:1. The size of the gene DNA was calculated to be 21 kbs or so according to themolecular weight Mrker(EcoR1-HindIII digest Lambda DNA).2. Various factor’s influence to RAPD-PCR results (different concentration oftemplate genetic DNA) and to SPRS-PCR (annealing temperature of the microsatellite primers) had been explored with experiment, finally the most suitable reaction systems with good stability and repetition had been established .3. Two genetic diversity index (gene diversity index and polymorphic rate ofloci) were using to analysis the RAPD-PCR results, the result showed thatthe DNA diversity among the same geographic population was lower than that of the different populations. The M.avenae population of Xinjiang spring wheat district was an exception, other seven regions showed that southern populations had smaller heredity variation than northern populations. Then the possibility could be drawn that it was concerned with the weather condition of the every locality area and primarily because of results of temperature pressure.4. Based on the analysis of Nei’s genetic distance (D), these genetic distanceof eight populations (0.23 ±0.016) were between that of geographic population (0.031± 0.007) and that of subspecies (0.23 ±0.016). The genetic differentiation of M.avenae among in different geographic district was only at the level of population level but had not achieved the subspecies level.5. The analysis of SPRS-PCR with clustering analyzing showed that the genetic difference of the M.avenae populations was obvious. And there were abundant DNA polymorphism among different populations. Xinjiang population, the unique spring wheat district population, was distinct from other 7 winter wheat districts populations, which was evolving to subspecies. There was a structure presented with our country third stairs geography steps degrees distribute. It could explain that climatic variety with the geography of our country and ocean current of air. The genetic variation of inter population in M.avenae populations of same stairs was greatly similar. The reason was M.avenae populations of same stairs grown in similar weather term and our country geography, plus the gene heredity drifting among populations.更多还原