彩色马铃薯块茎色素基因QTL定位及肉色表达机理解析

Colored potatoes are rich in anthocyanin. The anthocyanin, natural plant pigment, has function of high antioxidant activity. It makes colored potato becomes the hot point of plant pigment research. The anthocyanin of colored potato mainly comes from the tuber flesh. Research coloring mechanism of potato tuber is the key point to breeding high pigment content potato varieties. .Through making cross by different colored diploid potatoes, the project prepares several tuber color separation populations. Construct high density genetic map of colored potato through SSR analyzing and high flux SNP scanning. QTL mapping of tuber pigment genes, and developing molecular markers which linked the tuber flesh color by evaluating the pigment separation of colored potato populations..Analyze gene expression of enzyme genes and regulate genes of anthocyanin synthesis pathway in different colored potato tuber by RT-PCR technique. Combine with QTL mapping, analyzing the position in the chromosome and function of anthocyanin synthesis genes. Screening key genes expressed in tuber flesh of colored potato, and researching the coloring expression mechanism of the potato tuber flesh.

彩色马铃薯富含花青素，不仅使马铃薯块茎颜色丰富，更因其具高抗氧化活性功能及天然植物源色素的特点成为当前植物色素研究热点。而彩色马铃薯的花青素主要来自于块茎薯肉，了解块茎色素遗传分离规律是高色素含量彩色马铃薯新品种选育的关键。.项目拟用不同类型的二倍体彩色马铃薯配制杂交组合，构建块茎颜色分离群体；应用SSR和SNP等分子标记构建彩色马铃薯高密度遗传图谱，对块茎色素基因进行定位及QTL分析；结合块茎颜色分离分析，开发与块茎肉色性状连锁的分子标记。应用RT-PCR技术分析花青素合成途径各关键酶基因及其调节基因在马铃薯不同颜色块茎中的表达情况，结合色素基因QTL分析花青素合成相关基因在染色体上的位置和功能，筛选马铃薯块茎肉色表达关键基因，解析彩色马铃薯块茎肉色表达机理。

彩色马铃薯富含的花青素主要来自于薯肉，了解马铃薯块茎肉色遗传规律是高色素含量彩色马铃薯新品种选育的关键。本项目用白皮紫心和白皮红心等不同颜色类型的彩色马铃薯二倍体材料作为亲本配制杂交组合134个，根据亲本的颜色性状筛选18个组合进行田间评价，通过后代块茎色素分布筛选出3个候选群体G17-23，G17-25和G17-29；用高效液相法测定群体G17-23的花青素种类和含量；用简化基因组测序（RAD）技术开发SNP分子标记并构建彩色马铃薯遗传图谱；通过QTL分析定位的23个与花青素和类葫芦卜素合成途径相关的QTL位点主要分布在5号和7号染色体上；根据QTL定位位点设计19对引物用以筛选开发SCAR分子标记；应用RT-PCR技术在彩色马铃薯二倍体群体中对花青素合成途径相关基因进行分析，发现薯肉颜色的差异主要是结构基因表达量的差异或者没有表达所导致；研究发现已报道的几个色素表达关键基因与本研究的QTL定位位点不在同一条染色体上，说明存在其他基因影响花青素在块茎肉色中的表达。项目实施期间发表研究论文5篇；育成彩色马铃薯新品种2个；获云南省技术发明二等奖1项。