应用东乡野生稻回交重组自交系分析水稻耐低氮产量相关性状QTL

QTL Analysis for Yield Traits Related to Low Nitrogen Tolerance Using Backcrossing Recombinant Inbred Lines Derived from Dongxiang Wild Rice(Oryza rufipogon Griff.)

【目的】东乡野生稻低氮耐性强,是水稻耐低氮育种的重要资源。鉴定东乡野生稻耐低氮基因对研究耐低氮遗传机制、培育耐低氮水稻品种具有重要意义。【方法】利用协青早B//东乡野生稻/协B BC1F12回交重组自交系及其遗传图谱,应用Windows QTL Cartographer 2.5分析施氮肥和不施氮肥下的株高和产量相关性状QTL。【结果】共检测到57个控制株高和产量性状的QTL,分布于10条染色体上的33个区域,单个QTL表型贡献率为3.17%~63.40%,其中32个QTL的增效等位基因来自东乡野生稻。19个QTL在施氮和未施氮条件下均检测到,38个QTL仅在单一环境下检测到显著效应,表明不同施氮水平下水稻性状的遗传机制不同。【结论】43个QTL分别聚集于7条染色体上的14个QTL簇,表明不同性状涉及到共同遗传机制,并可通过分子标记辅助选择方法进行耐低氮有利等位基因的聚合育种。

【Objective】Dongxiang wild rice(Oryza rufipogon Griff.)has strong low nitrogen tolerance and is an important germplasm for low nitrogen tolerance improvement.Identification of genes responsible for low nitrogen tolerance in Dongxiang wild rice is of great importance to understand molecular mechanisms of low nitrogen tolerance and develop rice varieties with low nitrogen tolerance.【Method】Quantitative trait loci(QTLs)for plant height and yield traits under low and normal nitrogen conditions was identified using backcrossing recombinant inbred lines(BC1F12)derived from an interspecific cross Xieqingzao B//Dongxiang wild rice/Xieqingzao B and its genetic linkage.【Result】A total of 57 QTLs were detected in 33 regions on all chromosome,except chromosome 4 and 8.They explained individually 3.17%~63.40%phenotypic variation,and 32 QTLs of them had favorable alleles derived from Dongxiang wild rice.Nineteen QTLs were simultaneously detected under both nitrogen treatments,and 38 QTLs were only identified under single nitrogen treatment,suggesting various genetic mechanisms in rice growth and yield formation under low and normal nitrogen conditions.【Conclusion】Fourteen QTL clusters,43 QTLs included,scattered on seven chromosomes,indicating the common genetic-physiological mechanisms behind different traits,and the QTL pyramiding for low nitrogen tolerance can be achieved by molecular marker-assisted selection.