【作者】 韩英鹏；

【导师】 高继国； 李文滨；

【作者基本信息】 东北农业大学 ， 植物学， 2005， 硕士

【摘要】 分子辅助育种是越来越实用的一种育种技术,在育种实践过程中利用分子标记对重要农艺性状进行辅助选择,能够有效提高育种效率。关于大豆疫霉根腐病质量抗病基因的遗传定位研究已有大量的报导,但定位耐大豆疫霉根腐病数量性状遗传位点（QTLs）的研究却鲜见报导。鉴于近年来大豆疫霉根腐病数量性状抗性育种在世界各国得到高度重视,本研究的目的是定位与耐大豆疫霉根腐病相关的QTLs,用来指导大豆疫霉根腐病抗病育种工作。该研究以感病品系OX760和耐病品种Conrad及二者杂交所衍生的62个F_2:6重组自交系为材料,调查两个地点和两个年份的疫霉根腐病病害损失率;利用1200条RAPD引物和341对SSR引物对耐大豆疫霉根腐病进行基因定位。在1200条RAPD引物中,清晰可重复的多态性标记为39个,占3.25%;在341对SSR引物中,清晰可重复的多态性标记为45个,占13.2%。 本研究利用Mapmaker/EXP3.0b构建了大豆分子遗传连锁图谱,SSR和RAPD分子标记覆盖基因组的总长约3000cM。分子标记间的平均距离为29.7cM。分子标记主要集中在MLGF、MLGN、MLGD1b+w、MLGM四条染色体组上,这四条染色体上共有36个分子标记,占总标记数35.6%。其中标记最密集的两条染色体是MLGF和MLGM,各有10个标记。 本研究采用WinQTLCart（V2.0）软件进行QTL分析,LOD值大于2.0作为QTL存在的阈值,共发现分属于MLGD1b+W和MLGM连锁群的4个与耐大豆疫霉根腐病显著相关的分子标记,即:OPL18-800bp、OPN03-600bp,Satt536和Satt463。其对病害损失率的贡献率为13.34%到22.31%。与4个分子标记相对应的共有3个QTL位点,即:QPRR-1（QOPL18-800bp）,QPRR-2（QOPN03-600bp）和QPRR-3（QSatt536-Satt463）。其中QPRR-1和QPRR-2经多重QTL计算,对两年（2000年和2001年）和两点（Woodslee和Weaver）平均总病害损失率的贡献率为44.5%,而QPRR-3对2001年Woodslee试验点病害损失率的贡献率为15.2%。QPRR-1对2000年Woodslee试验点的病害损失率贡献率为21.55%,对2000年Wever试验点的病害损失率贡献率为16.71%,对两年（2000年和2001年）及两点（Woodslee和Weaver）平均总病害损失率的贡献率为22.31%。本试验发现数个在大多数生态环境条件下能重复出现的QTLs,可以作为育种工作中的重点选择指标,用以指导耐大豆疫霉根腐病的分子辅助育种。 该研究同时还表明,NTSYS（V2.11a）和GGEBIPLOT（V3.4）软件分析方法可以有效地应用于大豆抗病性分子研究中,其中NTSYS（V2.11a）可以将发现的与耐大豆疫霉根腐病相关的分子标记应用于62个F_2:6重组自交系的分组,正确率达到了95.16%。而GGEBIPLOT（V3.4）可以直观地表示QTL、株系与地点、年份之间的关系。更多还原

【Abstract】 Molelcular breeding is becoming more and more practical technology for plant breeding. The use of markers in plant breeding for indirect selection of important traits can favorably impact breeding efficiency. The present objective is to identify quantitative trait loci （QTLs） on the linkage groups, which are associated with the tolerance to soybean phytophthora root rot （PRR）, A RIL population from a cross between Conrad, a soybean cultivar tolerance to PRR disease, and OX760, a breedling lines susceptible to phythora root rot was used in this experiment DNA was extracted from F₆ RIL lines and amplified via polymerase chain reaction using simple sequence repeat （SSR） markers and Random Amplified Polymorphic DNA （RAPD） markers. A total of 39 RAPD markers and 45 SSR markers, which were polymorphic and clear segregated were used for subsequent QTLs analysis.Combining the resistance data resistance from two locations （Woodslee and Weaver） and two years （2000 and 2001）.All markers were used to construct a genetic linkage map using Mapmaker/EXP3.0b; putative QTLs were detected using WinQTLCart （V2.0）, if log-likelihood （LOD） was set as 2.0, Four markers OPL18-800bp, OPN03-600bp, Satt536 and Satt463, associated wih PRR Tolerance were detected on linkage group MLGD1b+w and linkage group MLGM, were significantly associated with PRR tolerance. They explained 13.34% to 22.31% of the phenotypic variance for the yield loss of caused by PRR disease. Three putative QTLs, namely QPRR-1 （QOPL18-800bp）, QPRR-2 （QOPN03-600bp） and QPRR-3 （QSatt536-Satt463） corresponding to these four markers, were identified. Multiple QTL analysis showed that QPRR-1 and QPRR-2 together explained 44.5% of the phenotypic variation for the yield loss based on the two locations （Woodslee and Weaver） and two years （2000 and 2001） data. QPRR-3 explained 15.2% of the phenotypic variation of the yield loss in Woodslee locations for year 2001. QPRR-1 explained 21.55% of the variation in Woodslee location for year 2000, 16.71% of the variation in Wever location for year 2000, and 22.31% of the variation in two locations （Woodslee and Weaver） for two years （2000 and 2001）. A few QTLs associated with the tolerance to PRR were detected to exist stably across mutiple environments in this study, which will benefit for the effetive selection of PRR tolerance soybean in breeding program。更多还原