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BNS小麦雄性不育性恢复基因遗传特性和QTL初步定位
Genetic Analysis and Priliminary QTL Mapping for Fertility of BNS
【作者】 王茂婷;
【导师】 高庆荣;
【作者基本信息】 山东农业大学 , 作物遗传育种, 2011, 硕士
【摘要】 为研究BNS小麦雄性不育性恢复的遗传特性和挖掘BNS雄性不育性恢复基因,本试验以光温敏雄性不育小麦BNS和恢复系SN055525为材料,构建(BNS×SN055525)F2群体和BC1回交群体,连续两年调查(BNS×SN055525)F2群体和BC1回交群体的自交结实率,确定BNS雄性不育性恢复基因的遗传特点;利用SSR分子标记在父母本间进行多态性引物的筛选,以2009年(BNS×SN055525)F2的300单株为作图群体,进行SSR标记分析,利用Mapmaker3.0b软件进行连锁分析,构建了SSR分子标记遗传图谱。采用基于混合线性模型的QTLNetwork 2.0软件对BNS小麦雄性不育性恢复相关性状进行初步的QTL定位研究。主要试验结果如下:(1)BNS的雄性不育性恢复由2~3对显性主效基因控制,同时受微效基因的影响,表现为典型的主效+微效修饰基因控制的特点;BNS的雄性不育性恢复受温度影响显著,是典型的温光敏雄性不育小麦。(2)选用2180对不同来源的SSR引物对父母本进行多态性筛选,从中筛选出具有多态性的引物组合258对,经进一步筛选,利用120对扩增清晰、稳定的多态性引物检测F2群体中的分离情况,大多数位点在群体中的分布符合3:1的分离比例。(3)采用Mapmaker3.0b软件进行连锁分析,构建了(BNS×SN055525)F2的遗传连锁图谱,含90个标记定位,覆盖了小麦17条染色体上,总长度为1276cM,标记之间平均遗传距离为14.4cM。单个染色体的标记数在2~10个范围内变化。根据已公布的分子标记间的距离和顺序,用Mapchart 2.1软件绘制遗传连锁图谱。(4)采用QTLnetwork2.0进行QTL分析结果表明,LOD>3.0时,共检测到14个与光温敏雄性不育性恢复相关的QTL位点,分布于染色体1A、1B、4A、4B和7B,LOD值为3.0~6.4,贡献率为4.0%~11.6%,将贡献率大于10%的2个主效QTL初步定位于1B和4A。
【Abstract】 BNS is a thermo-photo-sensitive male sterility line with stable genetic and sterility characteristics, which has broad use in research and production. To reveal the inheritance of male fertility of thermo-sensitive male sterile wheat lines and molecular characters of sterile gene for the breeding, the thermo-photo-sensitive male sterility line BNS and the restorer line SN055525 was used to construct the BC1 and F2 population in this study. The seed setting rate was investigated in two consecutive years to determine BNS fertility restoration gene genetic characteristics. SSR primers was screened the polymorphic between BNS and SN055525. The F2 population derived from BNS/SN055525 was constructed for mapping. molecular genetic linkage map was construct with Mapmaker3.0. QTL analyses were performed using the software of QTLNetwork 2.0 based on the mixed linear model approach according to the field experiment. The results are as follows:(1) Two years genetic study showed that BNS male sterility was controlled by 2~ 3 dominant genes and BNS had typical features of quantitative traits. Genetic analysis results indicated that the fertility distribution of F2 population was continuous, the difference of fertility distribution and segregation ration of (BNS×SN055525) F2 groups was significant. The reason was that the average temperature of 2010 in the thermo-sensitive stage of BNS from pistil and stamen differentiation stage to anther differentiation stage was 1~2℃lower than that in 2009 and improved the sterility of the population, which indicated ( BNS/SN055525 ) F2 fertility was affected by temperature and BNS was thermo-photo-sensitive male sterility line.(2) 300 plants of F2 population in 2009 for the construction of the genetic map. SSR primers was screened the polymorphic between BNS and SN055525. 2180 SSR primers had been screened the polymorphic between BNS and SN055525, among which 258 SSR primers had polymorphism, and detected the 300 plants of F2 segregation using polymorphic SSR markers. The result showed that the mapping population was suitable for map construction. (3) Genetic linkage map had been constructed by Mapmaker3.0 software and drew by Mapchart 2.1 based on the distance between two markers and marker order.18 of the 20 linkage groups could be assigned to 17 chromosomes based on the information from previous mapping studies. The genetic map contains 90 loci and 1267 cM with a mean marker interval of 14.4cM, with each chromosome comprising 2 to 10 locis.(4) Based on the genetic map established from the F2 population, the QTLwere detected using the software QTLNetwork version 2.0 with the composite interval mapping of the mixture linear model. 14 QTL for fertility restoration were located on chromosome 1A、1B、4A、4B and 7B, accounting for 4.0-11.6% of the phenotypic variance with a LOD from 3.0 to 6.4. The major QTL with a phenotypic variance higher than 10% were located on chromosome 1B and 4A.
【Key words】 BNS; thermo-photo-sensitive male sterility; SSR; genetic analysis; Genetic map; QTL;