This study aimed to screen drought stress indicators and analyze the drought resistance in 105 cultivated rice germplasm resources in Guangxi Zhuang Autonomous Region under drought stress in the whole growth period based on D value of seven morphological traits including panicle neck thickness,effective panicle number per plant,1 000-grain weight,filled grain number per panicle,total grain number,seed setting rate and yield per plant.According to the results,under drought stress,yield per plant exhibited significant positive correlation with panicle neck thickness and exhibited extremely significant positive correlation with other five morphological traits.Based on the identification and evaluation of comprehensive drought-resistance index D value,seven highly drought-resistant cultivated rice varieties were screened,accounting for 6.67％.Upland rice germplasm resources in Guangxi Zhuang Autonomous Region possess strong drought-resistance capacity,which could be used to screen highly drought-resistant rice germplasm materials.This study provided material basis and theoretical reference for breeding drought resistant rice cultivars in Guangxi Zhuang Autonomous Region.
水稻属盐敏感的作物,盐胁迫会导致产量显著减少。我国盐渍地总面积大,并且呈迅速增长趋势,因此,筛选水稻耐盐种质,培育耐盐水稻品种十分必要。本研究在1.5%NaCl盐胁迫条件下评价419份广西水稻地方品种核心种质种子芽期的相对盐害率,并利用全基因组关联分析鉴定耐盐位点。研究结果表明:盐胁迫下,种子芽期平均发芽率为57.67%,显著低于对照92.55%,且夏皮罗-威尔克检验(0.9301)不符合正态分布。基于208,993个SNP标记,将419份核心种质资源分为6个亚群,利用一般线性模型(general linear model,GLM)和混合线性模型(mixed linear model,MLM)分析分别获得129个和1个显著关联SNP,分布在1号、2号、3号、4号、5号、6号、8号、9号和12号染色体上。在14个与水稻耐盐性显著关联区域,有13个区域与前人定位或克隆的耐盐基因重叠。显著关联区域Chr.8:10,564,948~10,733,175为首次报道,命名为qGR8。qGR8区域内含有53个基因,其中34个经转录组数据比对获得表达谱,比对结果推测LOC_Os08g17370为候选基因,该基因为跨膜9超家族成员,在耐盐亲本的根部和叶部上调表达,可能为qGR8区域内水稻芽期耐盐的新基因。这些研究结果为耐盐新基因的克隆奠定基础,为培育耐盐水稻品种提供新的基因资源。
