Genetics of Adaptation in Wild Rice (Oryza)

自然选择的适应推动了新形式和新物种的进化。利用水稻的野生近缘作为研究系统，这项研究的长期目标是从遗传上识别并从生态上评估适应性突变。这项研究将为严格检验适应性进化的群体遗传学理论提供必要的实验数据，并为自然选择的基本机制提供直接证据。研究人员将利用F2群体进行遗传分析，以确定导致栽培水稻野生祖先Oryza nivara与其祖先多年生物种Oryza rufipogon适应性起源的主要突变的染色体位置和表型影响。同时，他们将培育出具有普通野生稻基因组背景和亚洲野生稻等位基因的近等基因系(NIL)。这些近等基因系可用于适应性进化基因的分子克隆和基因水平上的自然选择的实验测试。最近获得的水稻基因组序列极大地扩展了自然和农业种群的遗传研究范围。对栽培稻野生近缘自然变异的遗传解剖将为利用天然基因资源进行水稻和其他谷物品种的遗传改良提供机会。该项目将培养拥有从基因组学到生态学的垂直整合知识和研究经验的本科生、研究生和博士后研究人员。

Adaptation by natural selection drives the evolution of new forms and species. Using wild relatives of rice as a study system, the long-term goal of the research is to genetically identify and ecologically evaluate adaptive mutations. The study will yield experimental data necessary for the rigorous test of population genetic theories of adaptive evolution, and provide direct evidence for the basic mechanisms of natural selection. Using an F2 population, the investigators will conduct a genetic analysis to identify chromosomal locations and phenotypic impact of major mutations responsible for the adaptive origin of Oryza nivara, the wild progenitor of cultivated rice, from its ancestral perennial species Oryza rufipogon. Meanwhile, they will develop near-isogenic lines (NILs) that have the genomic background of O. rufipogon and alleles of O. nivara. The NILs can then be used for molecular cloning of genes underlying adaptive evolution and for experimental test of natural selection at the gene level. The recent availability of rice genome sequences greatly expands the scope of genetic studies in both natural and agricultural populations. The genetic dissection of natural variation in the wild relatives of cultivated rice will open opportunities for the genetic improvement of rice and other cereal cultivars utilizing natural gene resources. The project will train undergraduate and graduate students and postdoctoral researchers with vertically integrated knowledge and research experience from genomics to ecology.