许多重要农作物及经济动物都是多倍体，最具代表性的是同源四倍体的栽培马铃薯。随着世界人口快速增加、气候和环境不断恶化，可种植水稻、小麦等作物的耕地面积急剧下降，人类面临着前所未有的粮食安全危机。相对于水稻等常规作物而言，营养均衡的马铃薯对栽培的水、肥和土壤条件要求更低而产量更高，成为全球粮食安全战略中最重要的粮食作物之一。作为世界上马铃薯最大生产国，我国马铃薯单产和品质远落后于世界平均水平。由于同源四倍体物种基因分离、重组遗传规律的特殊性与复杂性，使得作为农艺性状遗传育种最重要的科学基础，多基因QTL定位分离这一重要的研究工作在四倍体中几乎处于空白。本项目拟发展适合于同源四倍体物种QTL定位分析的科学理论与实验分析方法，结合四倍体马铃薯农艺性状QTL定位的实验研究，为同源四倍体物种数量性状分子遗传解析提供严格的科学依据与方法，为栽培马铃薯块茎产量、薯块等重要农艺性状的遗传育种提供科学依据。

Many agronomically important crops and economically valued animals are autotetraploids, with cultivated potato being a typical example. As fast increase in the world population and accelerative change in climate and environment, the field suitable for growing traditional food crops like rice and wheat is shrinking rapidly. Humanity is facing an unprecedented severe challenge to food security. Potato needs much less stringent soil fertility and irrigation water to grow, but confers much higher yield of balanced nutritious tubers, making it the 3rd largest food crop and the future food of the world. Despite the largest potato producer, China has a much lower yield/hectare and tuber starch content than the world average. Understanding genetic control of the quantitative traits is the scientific basis to develop efficient breeding programs for genetically improved cultivars. However, the methods for mapping quantitative trait loci (QTL), which are built upon rigorous theoretical bases and have been routinely practiced in almost all important diploids, but are far less advanced in auotetraploid species primarily due to significant complexities of tetrasomic inheritance. In virtue of our 17 years of unbroken striving in both theoretical and experimental genetics of autotetraploid species, we proposed here to fill the gap by developing the theory and novel statistical methods for marker assisted genome-scanning for QTL in Autotetraploids with a full account for essential features of gene segregation and recombination in outbred populations of autotetraploid species. In parallel, we will test the utility and reliability of the methods through their implementation to model and analyze RAD-seq data and phenotypic data scored on a large segregating population from crossing two tetraploid potato cultivars which are phenotypically divergent in a series of important agronomic traits including flowering time, tuber yield, starch content etc. Success of the proposed project will solve a fundamental question in genetics, enable the quantitative genetic analyses in autotetraploid species to be conducted on a rigorous scientific basis and provides potato geneticists and breeders with useful analytical tools and valuable data.