马铃薯高密度遗传图谱构建及重要农艺性状QTL遗传分析

In the project density of the genetic map containing traditional markers will be further increased by developing abundant EST-SSR and InDel markers on the base of the established genetic map of autotetraploid potato and the located QTLs of the starch content and maturity traits. At the same time, the high-density molecular genetic map of atuotetraploid potato will be constructed by using TetraploidSNPMap software, which will be consist with the high throughput SNP markers. Nextly, the QTLs related potato starch and maturity traits will be accurately located in high-density genetic map by comparing consistency between the genetic map containing traditional marker and SNP markers. The authenticity and accuracy of located QTLs will to be tested and verified by analyzing of 80 high-starch cultivars with different maturity, and genes related with stable genetic major QTLs loci will be excavated and predicted by information of potato genome sequence and results of gene annotation. After this project will have accomplished, the molecular genetic mechanism of starch content and maturity traits in autotetraploid potato will be explored, molecular markers closely linked with the target traits will be developed, foundation of related genes cloning and molecular marker assisted selection breeding will be established.

本项目在已构建的同源四倍体遗传图谱和定位的淀粉含量、熟性性状QTLs基础上，通过开发丰富的EST-SSR、InDel标记对该传统标记遗传图谱进一步加密，同时对“陇薯8号×早大白”分离群体高通量SNP标记分析，利用TetraploidSNPMap软件构建四倍体马铃薯的高密度分子遗传图谱，比对传统标记和高通量SNP标记高密度遗传图谱的一致性，利用现有的表型鉴定数据精确定位马铃薯淀粉含量、熟性性状QTLs并开发与其紧密连锁的分子标记，并对不同熟性的80份高淀粉栽培种进行遗传分析，验证该QTLs的真实、准确性，根据马铃薯基因组序列信息及基因注释结果，对稳定遗传的主效QTLs进行基因挖掘及预测。本项目的完成将探明同源四倍体栽培种马铃薯淀粉含量、熟性等重要性状的分子遗传机理，开发出与目标性状紧密连锁的分子标记，为相关基因的克隆及分子标记辅助选择育种奠定基础。

项目在已构建的同源四倍体分离群体的基础上，利用Illumina GGP Potato-24 v1.0 Kit 芯片试剂盒（含12808个SNP标记）对分离群体LZ亲本及其231个子代进行了基因分型。入选5041个符合分离规律的标记，采用同源四倍体作图专用软件TetraploidSNPMap构建了含3130个（其中母本1021个，父本581个，双亲共有标记1528个）的高密度遗传连锁图谱。构建的高密度马铃薯连锁图谱全长915.28 cM，含3130个SNP标记，标记间平均距离0.3802cM，所有12条连锁群均含有完整的8条同源染色单体。采用3个生态点的10组数据，每组数据包括出苗期、熟性等28个农艺性状表型鉴定数据，利用TetraploidSNPMap区间作图法，28个性状共检测到797个相关位点，分布在所有的12个连锁群上，不同性状的位点检测数量差异较大，其中分枝数有15个位点，商品薯单薯重有37个位点；连锁群上检测到的位点差异较大，其中连锁群G8上有38个位点，连锁群G7上有170个位点。后续计划在多次重复检测到QTL的区间，利用10组表型数据计算最佳线性无偏估计量(best linear unbiased estimator, BLUE)，定位精确的各性状相关QTL位点，并进一步探索并挖掘关键位点。