利用二倍体马铃薯F2群体对结薯数目进行遗传分析

Potato is the most important tuber crop in the world. Cultivated potato is autotetraploid and has highly heterozygous genome, thus diploid potato is usually used in genetics analysis. However, most diploid potatoes are self-incompatible, which cannot be used to construct the traditional mapping populations, such F2, RIL, and etc. The self-incompatibility of diploid potato is controlled by a polymorphic allele S-RNase. The most efficient method to break self-incompatibility in diploid potato is utilization of the S-locus inhibitor gene (Sli) derived from wild potato Solanum chacoense. Tuber number is the most important factor determining the yield. In the previous study, an F2 population segregating for tuber number was produced by introgression of the Sli gene. An ultra-density genetic map will be constructed using the re-sequencing data of this F2 population, and the phenotype data of tuber number will be collected in three different growing seasons to reducing environmental noises. Based on the genetic map and phenotype data, quantitative trait loci controlling tuber number will be analyzed. The aim of this project is to explore the value of F2 population in the study of complex traits in potato.

马铃薯是最重要的块茎类粮食作物。栽培马铃薯为同源四倍体，基因组高度杂合，遗传分析困难，所以马铃薯的遗传研究主要在二倍体水平进行。但是，二倍体马铃薯多为自交不亲和，无法构建F2、RIL等常用作图群体，增加了遗传分析的难度。马铃薯的自交不亲和由高多态性的S位点控制。克服二倍体马铃薯自交不亲和最有效的方法是利用野生马铃薯Solanum chacoense中发现的S位点抑制基因（S-locus inhibitor，Sli）。结薯数目是马铃薯产量的主要构成因素。本项目组在前期研究中已经利用Sli基因构建了对结薯数目进行遗传分析的F2群体。我们将对F2群体进行低覆盖度重测序，构建高密度遗传图谱，同时对结薯数目进行三个生长季的表型鉴定，以降低环境条件的干扰。结合遗传图谱和表型鉴定结果，对控制结薯数目的QTL进行分析，探索二倍体F2群体在马铃薯复杂性状研究中的应用价值。

马铃薯是最重要的块茎类粮食作物。栽培马铃薯为同源四倍体，基因组高度杂合，遗传分析困难，所以马铃薯的遗传研究主要在二倍体水平进行。但是，二倍体马铃薯多为自交不亲和，无法构建F2、RIL等常用作图群体，增加了遗传分析的难度。马铃薯的自交不亲和由高多态性的S位点控制。克服二倍体马铃薯自交不亲和最有效的方法是利用野生马铃薯Solanum chacoense中发现的S位点抑制基因（S-locus inhibitor，Sli）。结薯数目是构成马铃薯产量的主要构成因素。本研究利用Sli基因构建了对结薯数目进行遗传分析的F2群体，并开发了一套不依赖于亲本的F1单倍型区分的方法。通过对F2群体进行遗传分析，定位到了两个控制结薯数目的QTL位点。本项目为高产马铃薯的分子设计育种提供了理论参考。