Linkage analysis of molecular markers and quantitative trait loci in populations of inbred backcross lines of Brassica napus L.
Linkage analysis of molecular markers and quantitative trait loci in populations of inbred backcross lines of Brassica napus L.
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DOI：
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发表时间：
1999-10
期刊：
影响因子：
3.3
通讯作者：
D. Butruille;R. Guries;Thomas C. Osborn
中科院分区：
文献类型：
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作者：
D. Butruille;R. Guries;Thomas C. Osborn
回交群体在F(2)、BC(1)或重组自交系等平衡群体中首次被发现后，常被用来研究数量性状基因座(QTL)。虽然后者在定位标记基因座方面更强大，但前者具有更精确地估计QTL效应所需的减少的背景遗传变异。许多近交回交系(IBL)群体已经在植物和动物系统中被开发出来，以允许同时研究和剖析从一个来源导入另一个来源的数量遗传变异。这些群体具有可用于QTL连锁估计和发现的遗传结构。本研究以甘蓝型油菜4个IBL群体为研究对象，对供体亲本(冬季型油菜品种)影响春型自交系和杂交种农艺性状的基因组区域进行了定位。在IBL中鉴定的限制性片段长度多态(RFLP)用于通过网格搜索计算两点重组分数和LOD分数。利用这些信息，用72个新的RFLP基因座丰富了甘蓝型油菜的复合遗传图谱。在两个生长季节对IBLS的自交和杂交后代的几个农艺性状进行了评估。利用回归分析方法，将系谱结构和图谱信息纳入QTL分析。检测到的每个性状的QTL数和用生物计量学方法计算的有效因子数具有相似的大小。IBL群体在分子标记定位和QTL分析中具有重要的应用价值。
Backcross populations are often used to study quantitative trait loci (QTL) after they are initially discovered in balanced populations, such as F(2), BC(1), or recombinant inbreds. While the latter are more powerful for mapping marker loci, the former have the reduced background genetic variation necessary for more precise estimation of QTL effects. Many populations of inbred backcross lines (IBLs) have been developed in plant and animal systems to permit simultaneous study and dissection of quantitative genetic variation introgressed from one source to another. Such populations have a genetic structure that can be used for linkage estimation and discovery of QTL. In this study, four populations of IBLs of oilseed Brassica napus were developed and analyzed to map genomic regions from the donor parent (a winter-type cultivar) that affect agronomic traits in spring-type inbreds and hybrids. Restriction fragment length polymorphisms (RFLPs) identified among the IBLs were used to calculate two-point recombination fractions and LOD scores through grid searches. This information allowed the enrichment of a composite genetic map of B. napus with 72 new RFLP loci. The selfed and hybrid progenies of the IBLs were evaluated during two growing seasons for several agronomic traits. Both pedigree structure and map information were incorporated into the QTL analysis by using a regression approach. The number of QTL detected for each trait and the number of effective factors calculated by using biometrical methods were of similar magnitude. Populations of IBLs were shown to be valuable for both marker mapping and QTL analysis.