Analysis of the genetic basis of heterosis in oilseed rape (Brassica napus) via comparative QTL mapping and expression QTL analysis

本课题的总体目标是比较分析油菜杂种优势的遗传控制。通过对不同B中杂种优势相关位点的QTL定位。油菜作图群体。在Gießen项目中，在初步工作中由分别具有高和低一般配合力的两个品系之间的杂交产生的双单倍体（DH）作图群体将用于构建基因组图谱，所述基因组图谱包含一组共有SSR标记，所述共有SSR标记也减缓了另一群体中的多态性以分离杂种优势效应，将由哥廷根大学在一个紧密结合的平行项目中建造。来自各自群体的个体DH系与普通雄性不育测试系之间的杂交的测试杂种的田间试验将使得能够鉴定和解剖对应于杂种优势表达的QTL。通过使用共同的标记，将有可能比对来自两个群体的遗传图谱，这意味着可以比对和比较在两个群体中鉴定的各自杂种优势相关QTL的位置、效应和相互作用。根据各自定位试验的结果，对两个群体杂种优势的遗传控制进行了研究和比较。这将带来关于以下迄今未回答的问题的重要信息：a）在不同的油菜群体中，是否相同的基因座参与杂种优势的表达，如果是这样，哪些基因座参与，以及参与的程度如何？B）不同的遗传机制（显性、超显性或上位性）对油菜杂种优势的贡献分别是什么，不同群体的遗传基础是否相同？

The overall aim of this project is a comparative analysis of the genetic control of heterosis in oilseed rape (Brassica napus L.) by QTL mapping of heterosis-relevant loci in different B. napus mapping populations. In the Gießen project a doubled haploid (DH) mapping population that has been generated in preliminary work from a cross between two lines with high and low general combining ability, respectively, will be used for construction of a genome map containing a set of consensus SSR markers that also slow polymorphisms in another population segregating for heterotic effects, to be constructed by the University of Göttingen in a closely-integrated parallel project. Field trials of test hybrids from crosses between the individual DH lines of the respective populations with common male-sterile tester lines will enable the identification and dissection of QTL that correspond to the expression of heterosis. By using common markers it will be possible to align the genetic maps from the two populations, meaning that the positions, effects and interactions of the respective heterosisrelevant QTL identified in the two populations can be aligned and compared. Based on the results of the respective mapping experiments, the genetic control of heterosis in the two populations will be studied and compared. This will bring important information regarding the following to date unanswered questions: a) Are the same loci involved in the expression of heterosis in different oilseed rape populations, and if so which loci are involved and to what extend? b) What is the respective contribution of different genetic mechanism (dominance, overdominance or epistasis) to heterosis in oilseed rape, and is the genetic basis the same in different populations?