【作者】 左慧；

【导师】 梁国华；

【作者基本信息】 扬州大学 ， 作物遗传育种， 2008， 硕士

【摘要】 水稻条纹叶枯病(Rice Stripe Disease)是由灰飞虱(Laodelphax striatellus Fallen)传播水稻条纹叶枯病毒(Rice Stripe Virus, RSV)引起的病毒病,主要发生在东亚的温带、亚热带地区。我国自1963年在苏南地区始发后,已逐渐扩散到大江南北的广大稻区。上世纪八、九十年代该病在我国总体发生较轻,近年来该病在我国的发生呈上升趋势,是当前我国水稻生产上的一种分布广,发生重,为害大的重要病毒病。由于近几年病害持续严重发生,生产上的许多抗病品种中也开始出现了一定的病株率。而目前使用的抗病品种抗源基础比较狭窄,主要是利用来自巴基斯坦籼稻Modan中的抗病基因Stv-bi,所以改变长期依靠单个基因抗性的现状,寻找新的抗病基因、培育优良抗病新品种成为当前防治水稻条纹叶枯病的首要任务。吴书俊博士利用抗病亲本籼稻Dular和感病亲本粳稻Balilla杂交构建的F2无性系群体,连续两年均检测到位于第11染色体上2个QTLs:qSTV-11b和qSTV-11c,并利用F3群体和BC1F1群体继续定位,最终将qSTV-11b定位在标记RM1355～STS11-31之间的269.6Kb的区域,将qSTV-11c定位在标记STS11-19～RM5349之间的440.1的区域。本研究是在吴书俊博士定位结果的基础上进行的,首先构建了包含qSTV-11b的一系列染色体片段渐渗系,通过分析这些渐渗系田间抗病性情况和分子标记的检测结果,将qSTV-11b精细定位,并初步确定了qSTV-11b的候选基因。目前取得的研究结果主要有:1构建了24个qSTV-11b附近染色体片段渐渗系。这些染色体片段渐渗系分别来源于不同BC3F2单株,利用12个STS标记覆盖了qSTV-11b附近的333.50Kb的染色体区间。2对这些染色体片段渐渗系进行田间抗病性调查。表明:以感病亲本Balilla为对照,有8个渐渗系的发病率与对照相比达到极显著水平,表现抗病;有15个渐渗系的发病率与对照相比不显著,表现感病;1个渐渗系的发病率达显著水平。以抗病亲本Dular为对照时,株系抗感病性状与以感病亲本Balilla为对照时所得结论一致。3通过这些染色体片段渐渗系的抗病表现以及分子标记的检测结果,将qSTV-11b定位在标记在A38～A36之间25.39Kb的区域内。该区域有5个基因,通过测序比对分析,其中有1个基因在抗感病品种间有差异。因此认定该基因可能为qSTV-11b的候选基因。更多还原

【Abstract】 Rice stripe disease, a kind of viral diseases of rice, is transmitted by the small brown planthopper, Laodelphax striatellus Fallen and mainly occurs in temperate and subtropics zones of East Asia.Rice stripe disease first occurred in Southern Jiangsu in 1963 and it spread all the rice region in China.In 1980s and 1990s, rice stripe disease is not so serious, but the disease is rising in recent years in China, and it had caused a great loss of rice production. With the severe occuurence of the disease, some susceptible plants could also be found in resistant varieties.At present, the most of resistant rice varieties mainly carry the resistant gene Stv-bi which comes from indica rice variety Modan.However, varieties with a single resistance gene may lose their resistance if a new virus strain can overcome the resistance of Stv-bi, it is necessary to find new genes which are resistant to RSV.Wu,et al used F2 lines derived from a cross between the susceptible japonica variety Balilla and the resistant indica variety Dular to assay the resistant loci, and two loci were detected which were both on chromosome 11 with the name of qSTV-11b and qSTV-11c respectively. And then Wu continued to use F3 and BC1F1 population to locate the two loci precisely.At last, qSTV-11b was located in the interval of RM1355～STS11-31 and STS11-19～RM5349 respectively,and the physical distance is 269.6Kb and 440.1Kb.The fine mapping of qSTV-11b was carried out in this study, and the results were as follows:1 Twenty-four introgression lines were constructed, which overlapped the interval of qSTV-11b.These twenty-four introgression lines originated from different plants of BC2F2 population.There were twelve STS markers in the interval of qSTV-11b, and these markers overlapped the physical distance of 330.50Kb.2 The resistance to RSV of twenty-four introgression lines was investigated. Compared to the infection rate of susceptible control Balilla, that of eight introgression lines was very significant, and that of fifteen introgression lines’was not significant, and that of one introgression line’s was significant. Compared to the resistant control Dular, the result of these introgression lines was the same.3 The qSTV-11b was located between A38 and A36,and the physical distance of the two markers is 25.39Kb.There are five genes in the interval of the two markers,and difference is found in one of the five genes in the resistant and susceptible varieties by sequencing and blasting.So the gene was preliminarily considered as the candidate gene of qSTV-11b.更多还原