论文部分内容阅读
稻瘟病是目前最具毁灭性的作物病害之一.本研究通过由田间菌株CHL346和CHL42杂交得到的189个子囊孢子菌株构建的分离群体,在亲本菌株CHL346中鉴定到了与水稻稻瘟病抗性基因Pi7对应的无毒基因AvrPi7.为了确定AvrPi7位点的染色体位置,本研究开发了一套基于稻瘟病菌测序菌株70-15全基因组序列的121个微卫星(simple sequence repeat,SSR)标记.利用这些SSR标记对AvrPi7位点进行了连锁分析.结果表明,位于第1染色体的8个SSR标记与该无毒基因连锁,其中2个最近的侧翼标记MS1-9和MS1-15分别距离AvrPi7位点3.2和16.4cM.为了进一步完成该位点的精细作图,在MS1-9和MS1-15的侧翼区域进一步开发了8个SSR标记和3个候选无毒基因(candidate avirulence gene,CAG)标记.通过对这些标记的连锁分析,AvrPi7位点被界定于标记MS1-21和MS1-22之间1.6cM的区域内,并与标记CAG2共分离.为了构建该无毒位点的物理图谱,通过生物信息学分析(bioinformation analysis,BIA),将与该基因连锁的分子标记分别着陆于参考菌株70-15的超重叠群(supcontig)上.AvrPi7位点最终被界定在标记MS1-21和MS1-22之间的75kb区段内.本研究的结果对于进一步了解真菌中普遍存在的重组不平衡和部分二倍体等现象,以及对该基因进行克隆及其功能研究具有重要意义.
Rice blast is one of the most devastating crop diseases at present.In this study, a population of 189 ascosporogenous strains isolated from the field strains CHL346 and CHL42 was used to isolate the rice blast resistance genes In order to determine the chromosomal location of the AvrPi7 site, we developed a set of 121 simple sequence repeat (SSR) markers based on the complete genome sequence of strain 70-15 of Magnaporthe grisea, These SSR markers were linked to the AvrPi7 locus and the results showed that 8 SSR markers located on chromosome 1 were linked to this avirulent gene and two of the most recent flanking markers, MS1-9 and MS1-15, were distant from the AvrPi7 site 3.2 and 16.4 cM. To further refine the mapping of this locus, 8 SSR markers and 3 candidate avirulence gene (CAG) markers were further developed on the flanking regions of MS1-9 and MS1-15. By linkage analysis of these markers, the AvrPi7 site was defined within the 1.6 cM region between the marker MS1-21 and MS1-22 and co-segregated with the marker CAG 2. To construct the physical map of this non-toxic site, Bioinformation analysis (BIA), molecular markers linked to this gene were respectively landed on the supcontig of the reference strain 70- 15. The AvrPi7 site was finally defined on the MS1-21 and MS1-22 In the 75kb region between the results of this study to further understand the fungal common imbalance and part of the diploid and so on, as well as the cloning and function of the gene is of great significance.