烟草重组自交系氮素利用效率的遗传分析及QTL定位

Nitrogen is an essential element for crop growth. In China, the application of huge amount of nitrogen fertilizer for crop production with low nitrogen use efficiency results in increased planting cost, and is harmful to the environment as well. Therefore, it is urgent to elucidate the genetic and molecular mechanism of nitrogen use in crops to breed new varieties with improved nitrogen use efficiency(NUE). At present, the study on plant NUE has mainly focused on the model plant and the cereal crops, which latter take seeds as the evaluation standard. However, the study on NUE of economic crops for leaf production, such as tobacco, has been limited. The research team have developed recombinant inbred lines (RILs) derived from a cross of two tobacco varieties, Yunyan 87 and Yanyan97, which have significant differences in NUE. In the proposed study, the RILs will be grown under the conditions of hydroponic cultivation, pot cultivation and field test, meanwhile be treated with different nitrogen levels. In those tests, phenotype such as leaf biomass, chlorophyll content and nitrogen content will be collected from the RILs. Combined phenotype data and genotype data, statistic genetic analysis and QTL analysis will be carried out to unveil the genetic basis, calculate QTLs and develop tightly linked molecular markers of high nitrogen use efficiency traits. Our study will contribute to elucidate the molecular mechanism of nitrogen utilization in tobacco and other plant for leaf production, and lay a theoretical foundation for the NUE improvement of tobacco variety.

氮元素是作物生长的必要元素。我国氮肥施用量巨大，且利用效率低，造成生产成本增加及农业生态环境不断恶化。因此，亟需阐明作物氮高效利用的遗传与分子机理，并培育氮高效利用型新品种。目前，植物的氮利用效率机理研究多集中在模式植物与以种子为评价目标的谷类作物中，而叶用经济作物烟草的氮利用效率的分子机制尚不清楚。项目组以两个氮利用效率存在显著差异的品种云烟87和岩烟97为亲本，培育了重组自交系群体。在此基础上，本项目拟在不同施氮量处理条件下开展水培、盆栽及大田试验，进行叶片生物量、叶绿素、含氮量等氮利用效率表型测定，结合群体的SNP基因型和表型数据，研究烟草氮高效利用性状的遗传模式，并定位控制该性状的QTL，同时开发与烟草氮高效利用性状紧密连锁的分子标记。本研究将有助于阐明烟草等叶用作物氮利用的分子机制，并为培育氮高效利用型的烟草品种奠定理论基础。

氮元素是作物生长的必要元素。我国氮肥施用量巨大，且利用效率低，造成生产成本增加及农业生态环境不断恶化。因此，亟需阐明作物氮高效利用的遗传与分子机理，并培育氮高效利用型新品种。目前，植物的氮利用效率机理研究多集中在模式植物与以种子为评价目标的谷类作物中，而叶用经济作物烟草的氮利用效率的分子机制尚不清楚。项目组以两个氮利用效率存在显著差异的品种云烟87和岩烟97为亲本，培育了重组自交系群体。在此基础上，本项目拟在不同施氮量处理条件下开展水培、盆栽及大田试验，进行叶片生物量、叶绿素、含氮量等氮利用效率表型测定，结合群体的SNP基因型和表型数据，研究烟草氮高效利用性状的遗传模式，并定位控制该性状的QTL，同时开发与烟草氮高效利用性状紧密连锁的分子标记。本研究将有助于阐明烟草等叶用作物氮利用的分子机制，并为培育氮高效利用型的烟草品种奠定理论基础。.项目获得了不同发育时期、不同氮素水平下大田、盆栽等生长条件下的多年多点QTL分析结果，获得了多个氮高效紧密连锁的分子标记，其中贡献度较高（大于6%）的标记4个。通过多年选育获得了4个品系，在2个地点小区试验中产量与产值均好于对照品种，后续将在此基础上开展品种选育试验，为品种的稳产增产作出贡献。