马铃薯自交不亲和抑制基因Sli的精细遗传定位

China has become the largest potato producing country not only for potato cultivation area but also in Megaton potato production. The development of potato agribusiness plays a key role for securing the food safty in China. The traditional potato breeding is based on the tetraploidhybridization, but the breeding process was quite slow. In recent years diploid F1 breeding is becoming the front edge of international potato research, which would be an alternative approach of potato breeding. The definition of diploid F1 true seed breeding is to culture favor inbreding lines by eliminating harmful genes and to compound a vigour combination. Depression of inbreding incompatibility is the priority condition for exploring diploid F1 breeding.Previous study reportedabout the Sli gene originating from Solanum chacoense that renders diploid potatoself-compatible, which was located in the twelfth chromosome of potato. Taking adavantage of international exchange, we got the diploid homozygote of Sli gene and segregated population for primary mapping in the previous study. With the full genome of potato available, this project will re-sequence the diploid homozygote containing the Sli gene and fine-map this gene by compatible genomic analysis and genetic mapping. This research will establish the cornerstone for cloning the Sli gene and achiving diploid F1 breeding.

我国是世界马铃薯生产第一大国，发展马铃薯产业对保证我国粮食安全有着十分重要的意义。传统马铃薯育种基于四倍体杂交选育，育种进程非常缓慢。近些年二倍体F1实生种育种成为国际马铃薯研究的前沿，有可能替代传统的四倍体育种方式。二倍体F1实生种育种通过不断自交剔除掉有害基因培育优良自交系，进而配制优良组合。抑制自交不亲和是开展二倍体F1育种的优先条件。前人在野生二倍体材料中发现了可以抑制二倍马铃薯自交不亲和的Sli基因，并初步定位在第12号染色体。通过国际交流，我们已经得到了Sli基因的纯合材料和初步定位的分离群体。在马铃薯基因组测序完成的基础上，本项目拟对含Sli基因二倍纯合材料进行重测序，通过基因组比较分析和遗传作图，对Sli基因进行精细遗传定位。本研究为该基因的最终克隆和二倍体F1分子育种奠定基础。

马铃薯是世界上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，遗传改良困难。而且，传统的薯块繁殖存在易带毒、用种量大、运输成本高等问题。利用二倍体实生种子生产可以解决上述问题。但是，二倍体马铃薯具有自交不亲和的特点，要实现二倍体实生种子生产首先需要解决自交不亲和的问题。野生马铃薯Solanum chacoense chc525-3中含有抑制自交不亲和的Sli基因，该基因在二倍体育种中具有重要的作用。我们通过对含有Sli基因的材料chc525-3和8H1-3进行基因组分析，推断Sli基因位于2号染色体38Mb到42Mb的区域。然后通过转录组测序，分析候选区域基因的表达情况，鉴定了9个在花药中特异表达的基因，定为Sli的候选基因。