水稻萌发耐淹性种质资源筛选及QTL定位

萌发耐淹性种质资源的筛选、耐低氧萌发基因的挖掘和利用是选育适宜直播水稻新品种的基础。为简便、高效的评价种质资源的萌发耐淹性,本研究对来自不同年代和地区的191份粳稻种质资源进行了萌发耐淹性鉴定,共获得12份萌发耐淹性强的种质资源,其中连粳15号表现出较强的低氧萌发能力。利用其与籼稻品种黄莉占构建的F2:3分离群体,采用模拟大田的鉴定方法,在水稻1号、3号、9号、10号染色体上共检测到4个QTL,即qGS1、qGS3、qGS9和qGS10。共解释表型变异的70.9%,其中qGS1、qGS3和qGS10,能够被重复检测到,贡献率分别为19.2%~24.0%、12.6%~14.7%、19.1%~20.5%,是稳定表达的QTL位点。这些种质资源和QTL的发现为耐低氧发芽水稻新品种的培育提供了重要的亲本资源、基因资源和标记资源,同时也为选育优良直播稻品种提供了理论依据。

Screening of germplasm resources and QTL mapping for germinability under submerged condition in rice(Oryza sativa L.)

Screening of germplasm resources,exploiting and utilization of genes conferring tolerance to hypoxia are the key to breeding new cultivars adapted to direct seeding.In order to evaluate the germinability of germplasm resources under submerged condition in a simple and efficient way,191 japonica germplasm resources released from different years and regions were screened,12 japonica varieties with high germinability under submerged condition were found.Among them,Lianjing 15,a japonica variety,showed stable and high tolerance to hypoxia.Using a F2:3 population derived from Lianjing 15 and Huanglizhan(HLZ,a highly susceptible indica rice variety),four quantitative trait loci(QTL)conferring tolerance to hypoxia,namely qGS1,qGS3,qGS9,and qGS10 were identified under simulated field environment,and they explained 70.9%of the total phenotypic variation.Among them,qGS1,qGS3,and qGS10,were repeatedly detected in different years,accounting for 19.2%–24.0%,12.6%–14.7%,and 19.1%–20.5%of the total phenotypic variation,respectively.The germplasm resources and QTL found in our study would provide innovative resources for breeding rice cultivars with high germinability under submerged condition,and would also provide a theoretical basis for breeding varieties adapted to direct seeding.