【作者】 滕希；

【导师】 万方浩；

【作者基本信息】 中国农业科学院 ， 生物安全， 2009， 硕士

【摘要】 烟粉虱Bemisia tabaci(Gennadius)是由在形态学上难以区分的多种生物型所组成的复合种,在多个国家和地区均造成了巨大的经济损失。在烟粉虱众多生物型中,Q型烟粉虱依靠其对极限温度和多种农药的强耐受性等优势,近年来开始在世界范围内扩散,并显示出比B型烟粉虱更强的入侵性和危害性。本论文采用mtCOI分子标记和SCAR分子标记的方法对在全国范围内系统采集的24个烟粉虱样本进行了生物型鉴定,确定了Q型烟粉虱在我国的分布现状,并利用基于mtCOI序列的系统发育分析推测我国Q型烟粉虱的入侵来源。主要结果和结论如下:1.从2003年首次发现至2007年的四年期间,Q型烟粉虱在我国发生了快速扩张,其入侵范围已经从最初的云南昆明扩大至全国14个省、市、自治区范围内的共20个地区,这些地区包括:荆州、襄樊、武汉(湖北省),莱阳、泰安(山东省),三亚(海南省),桂林、南宁(广西自治区),贵阳(贵州省),杭州、宁波(浙江省),湘潭、岳阳(湖南省),扬州(江苏省),新乡(河南省),宝鸡(陕西省),酒泉(甘肃省),运城(山西省),福州(福建省),天津;2. Q型烟粉虱在中国的地理分布具有不平衡性并且在不同地区的入侵程度有所不同:在经济较发达、交通相对频繁的东南部省区,Q型烟粉虱分布较普遍,并且在其中的大部分地区,Q型烟粉虱所占供试样本的比例大于50%,如岳阳、湘潭(湖南省),杭州(浙江省),荆州、襄樊、武汉(湖北省),扬州(江苏省),三亚(海南省),福州(福建省);而在相对经济落后的西部地区(如甘肃、陕西、贵州、广西)也发现了Q型烟粉虱,但是其比例均低于50%; Q型烟粉虱在中国的这种分布情况和入侵程度可能与人类活动有着密切的关系;3. Q型烟粉虱具有取代B型烟粉虱从而进一步扩张的趋势:在Q型烟粉虱的分布地区存在明显的B/Q烟粉虱共存的现象(除了福州之外,在其他19个检测到Q型烟粉虱的地理区域中同时也检测到B型烟粉虱的存在),不同地区的B/Q构成比例不同,这在一定程度上体现了Q型烟粉虱和原有B型烟粉虱的竞争及Q型烟粉虱对B型烟粉虱的替代过程正在发生;4.基于mtCOI序列的系统发育分析:共43个具有典型代表意义的mtCOI序列提交GenBank,登录号为FJ375346-FJ375358,FJ594428-FJ594434 and FJ647195-FJ647217。基于mtCOI序列进行聚类的系统发育分析表明:来自中国的Q型烟粉虱同来自西班牙、危地马拉、韩国、葡萄牙、希腊、日本和摩洛哥的Q型烟粉虱聚为一个分支,即中国的Q型烟粉虱同来自Q1分支的Q型烟粉虱亲缘关系更近,形成了一个分支,并且与Q2分支的Q型烟粉虱明显的分为了两个分支,由此可以推测中国Q型烟粉虱的起源地为地中海西部国家或地区。更多还原

【Abstract】 The sweet potato whitefly, Bemisia tabaci (Gennadius), is a serious pest of different agricultural crops all over the world. B. tabaci was considered a species complex containing many genetically differentiated populations, which can not be distinguished by morphological characteristics, among which B and Q biotype were widely distributed and well-studied. Many researches proved that B. tabaci biotype Q has better survival than biotype B due to higher tolerance to extreme temperature and greater resistance to insecticides, and biotype Q has spread worldwidely. Using two methods of mtCOI and SCAR molecular markers, the present study was, therefore, initiated to extensively and systematically survey the newly introduced biotype Q, which will unveil its significance and current distribution in the main agricultural ecosystems across the country. Furthermore, valid percentage of biotype Q in different B. tabaci populations will be determined and the phylogenetic analysis based on mtCOI sequences was given to infer the original lacation of B. tabaci.biotype Q in China. The main results and conclusion were as follows,1. In the four years from 2003 to 2007, B. tabaci biotype Q had become widely dispersed, it was only in kunming (Yunnan Province) that biotype Q was firstly discovered in 2003, however, B. tabaci biotype Q was found in 20 populations by the two molecular markers from Jingzhou, Xiangfan and Wuhan (Hubei Province), Laiyang and Taian (Shandong Province), Sanya (Hainan Province), Guilin and Nanning (Guangxi Autonomous Region), Guiyang (Guizhou Province), Hangzhou and Ningbo (Zhejiang Province), Xiangtan and Yueyang (Hunan Province), Yangzhou (Jiangsu Province), Xinxiang (Henan Province), Baoji (Shaanxi Province), Jiuquan (Gansu Province), Yuncheng (Shanxi Province), Fuzhou (Fujian Province) and Tianjin. The biotype Q was not found in the four populations from Tulufan (Xinjiang Uigur Autonomous Region), Chengde and Langfang (Hebei province) and Hefei (Anhui Province).2. The invasive status of B. tabaci biotype Q in different regions was various: The biotype Q has successfully invaded majority of southeastern provinces, where traffic and transportation are comparatively frequent than other provinces in the country. Moreover, the proportion of biotype Q is higher than 50% in most of these provinces. In addition, the biotype Q is also distributed in several under-developed western provinces (e.g., Gansu, Shaanxi, Guizhou, Guangxi), but with lesser than 50% proportion. The distribution of B. tabaci biotype Q in China was related with human activities.3. There is high probability that biotype Q will further spread to other regions by displacing biotype B. Using mtCOI sequencing, the biotype Q was detected in 20 populations in which biotype B was also found except in the population from Fuzhou (Fujian Province). There is high probability that biotype Q will further spread to other regions by displacing the biotype B, due to its greater tolerance to extreme temperature and resistance to insecticides than the biotype B. 4. Phylogenetic analysis based on mtCOI sequences:The GenBank accession numbers of the sequences representing the different geographic populations of the country were FJ375346-FJ375358, FJ594428-FJ594434 and FJ647195-FJ647217. The phylogenetic tree also showed that: twenty sequences of mt CO1 gene (FJ375346-FJ375358, FJ594428-FJ59 4434) of B. tabaci in China were grouped with individuals of biotype Q from Spain and other 6 countries, forming a sub-clade, with more . The other sub-clade contained biotype Q from Israel (DQ365878), Cyprus (DQ365877) and Turkey (AF342776) with the support value of 95%. It was inferred that B. tabaci biotype Q in China was introduced from western Mediterranean countries.更多还原