生菜和莴苣是世界上最重要的蔬菜之一。由于有色生菜/莴苣中的花青素具有抗氧化、抗癌和抗衰老作用，紫色和红色生菜/莴苣越来越受到消费者的青睐。叶色是生菜重要农艺性状之一，但生菜叶色相关研究仍较少。本项目前期工作利用紫色生菜和绿色油麦菜（叶用莴苣）进行杂交，构建F2叶色分离群体,通过传统遗传学和第二代测序技术相结合的方法已快速定位了3个控制紫色生菜的位点（PLL1-3），发现该分离群体中还有至少1个（PLL4）未定位的紫色调控基因。本研究拟精细定位这4个基因，克隆至少其中2个并分析其作用的分子机理。根据这些基因扫描本实验室收集的950份生菜材料，找到含有其它紫色调控基因的生菜/莴苣品种，建立新的分离群体，利用上述方法快速定位叶色调控基因。本研究将系统分析生菜中紫色调控基因以及作用机理，为一步了解花青素的合成与调控以及培育高含量花青素的生菜品种奠定基础。

Lettuce is one of the most important vegetables worldwide. Purple/red lettuce is welcome by consumers due to its color appearance and health benefits. Purple/red color of lettuce leaf is attributed to anthocyanin, accumulated in the epidermal cells of leaf. Anthocyanin is shown to be a strong antioxidant, and high concentration of anthocyanin in food has efficient anticancer effects.The research on leaf colour is still rare, though leaf, the harvest organ, is one of important horticultural traits. Green and purple are the two main colors of lettuce leaf, though different cultivars may vary slightly. In this proposed study, we will map and clone genes controlling purple leaf of lettuce. Primary study, which combined traditions genetics approach and the second generation sequencing technology, successfully mapped three loci (PLL1-3) controlling leaf color. At least one additional locus (PLL4) controlling purple leaf exists in this segregating population. We are going to fine map and clone at least two of them, and then analyze their molecular mechanisms. These four genes (or loci) controlling purple leaf will be used to screen a collection of 950 lettuce cultivars. If a purple cultivar does not have these four genes, it will be considered to harbor new sources of genes controlling purple lettuce leaf. Highly linked markers will be developed for these new genes. The cloned genes and markers highly linked with new source of genes controlling purple leaf will be helpful for the development of cultivars with high concentration of anthocyanin in lettuce.