Lianyungang Academy of Agricultural Sciences/Jiangsu Collaborative Innovation Center for Modern Corp Production
National Project for Modern Agricultural Technology System (CARS-01-61); Project for Agricultural Significant New Varieties Breeding of Jiangsu Province (PZCZ201704); Natural Science Foundation of Jiangsu Province of China (BK20201214); Revitalization of the Seed Industry Project of Jiangsu Province (JBGS039); Financial Grant Support Program of Lianyungang City (QNJJ2203, QNJJ2306); Sixth ‘521 Project’ Research Program of Lianyungang (LYG06521202205)
通过对水稻萌发耐淹性进行QTL定位和稳定位点的聚合效应分析,可以为萌发耐淹性基因的精细定位及后续分子辅助育种奠定基础。本研究利用一个包含144份家系的强萌发耐淹性粳型杂草稻WR-4与籼稻品种广百香占的F2:3定位群体,基于1K mGPS SNP芯片构建了一个包含825个Bin标记的高密度遗传图谱,利用完备区间作图法共检测到10个萌发耐淹性QTL,分布于水稻第3、4、7、8、9和10染色体上,LOD值介于3.6~21.3之间,可解释3.0%~21.1%的表型变异。其中,具有较高LOD值和贡献率的2个主效QTL(qGS4-1和qGS7-1)能够被重复检测到,是后续基因功能研究的候选位点。根据Bin标记分型结果将不同子代在两个稳定QTL区间内分为WR型和广百香占型,在F2:3群体中进行聚合效应分析,发现聚合增效等位基因数量越多的家系,其淹水条件下的胚芽鞘越长,这些携带多个耐性QTL的株系可为分子育种培育耐低氧萌发水稻新品种提供亲本资源。
QTL mapping of germinability under submergence condition and pyramided effect analysis of stable sites were carried out to lay a foundation for fine mapping of QTL for germinability under submergence condition and marker-assisted breeding. Using an F2:3 population with 144 individuals derived from a cross between WR-4 (a weedy rice with strong germinability under submergence condition) and Guangbaixiangzhan (a susceptible indica variety, GBXZ), a high density genetic map with 825 bin markers was constructed based on 1K mGPS SNP chip. As a result, ten QTL conferring tolerance to hypoxia were identified by complete interval mapping (ICIM), which were located on chromosomes 3, 4, 7, 8, 9, and 10, with LOD values ranging from 3.6 to 21.3, explaining phenotypic variation of 3.0%-21.1%. Among them, two major QTL (qGS4-1 and qGS7-1) with high LOD value and high phenotypic variance, were repeatedly detected, and these two loci could be the candidate loci for subsequent gene function studies. According to the genotyping of bin markers, different progenies were divided into WR type and GBXZ type in each QTL interval. Further data processing and analysis were performed to analyze the pyramided effect of QTL. It was found that individuals with more pyramided synergistic alleles showed longer coleoptile under submergence condition. The identified lines with multiple synergistic alleles provide innovative resources for breeding rice cultivars with high germinability under submergence condition.