Molecular and quantitative genetic analysis of seed size in Faba Bean (Vicia faba L.)

蚕豆 (Vicia faba L.) 种子大小的分子和定量遗传分析

• 批准号: 436288468
• 负责人: Professor Dr. Wolfgang Link
• 金额: --
• 依托单位: Abteilung Zuchtmethodik der Pflanze
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/436288468?language=en
• 关键词: Molecular; quantitative; genetic; analysis; seed

In grain legumes seed size, a major yield related trait, varies considerably between species but also within species, with an extreme case found in Vicia faba, where seed size between the minor and major groups can vary by a factor of about 15. In faba bean, seed size is controlled by the size of the seed coat, a maternal organ. To elucidate the genetic control of seed size, transcriptome profiles will be determined at different stages during the growth of the seed coat in two near isogenic lines of faba bean distinguished by a large difference in seed size. This will be complemented by a QTL mapping for seed size in a RIL population derived from a cross of the two lines. By analysing the transcriptome profiles, the differentially expressed gene networks, underlying the difference in seed size between the two isogenic lines, will be identified. To identify the causal factors responsible for the seed size difference, the results from the transcriptome profiling will be combined with the QTL mapping results. For this, the transcripts will first be mapped on the genome sequence of Medicago truncatula and the known synteny between M. truncatula and V. faba will be used to identify differentially expressed genes which fall within the confidence intervals of mapped QTL. Based on gene ontology analyses and information available from the literature, a set of candidate genes for the mapped QTL will be selected and their expression profiles will be verified by qPCR. Finally, the phenotypic effects of the selected candidate genes with respect to seed size will be verified in at least two of three F2 populations segregating for this trait, which will be developed from crosses between minor and major genotypes unrelated to the isogenic lines.

在豆科植物中，种子大小是与产量相关的一个主要性状，在物种之间和物种内部都有很大差异，在蚕豆中发现了一个极端的例子，小群体和大群体之间的种子大小可以相差约15倍。在蚕豆中，种子的大小由种皮的大小控制，种皮是母体的一个器官。为了阐明种子大小的遗传控制，我们将测定两个种子大小差异较大的近等基因蚕豆系种皮生长不同阶段的转录组谱。这将通过两个系杂交得到的RIL群体的种子大小QTL定位加以补充。通过分析转录组谱，将确定导致两种等基因系种子大小差异的差异表达基因网络。为了确定造成种子大小差异的原因，转录组分析结果将与QTL定位结果相结合。为此，转录本将首先被定位到短形紫花苜蓿的基因组序列上，并利用已知的短形紫花苜蓿和蚕豆紫花苜蓿之间的同源性来鉴定在定位的QTL置信区间内的差异表达基因。基于基因本体分析和文献信息，选择一组候选基因用于定位QTL，并通过qPCR验证其表达谱。最后，选择的候选基因在种子大小方面的表型效应将在与等基因系无关的次要基因型和主要基因型之间的杂交中分离的3个F2群体中的至少2个群体中得到验证。