Mapping of a Novel Semisterile Pollen QTL in Rice

The objective of this study was to understand the genetic basis of pollen sterility of indica–japonica hybrid rice (Oryza sativa L.). From a set of chromosomal segment substitution lines that each contains a single or few of segments from the japonica variety Nipponbare in the genetic background of the indica variety Zhenshan 97B, IL37 was identified as a semisterility line. This substitution line contained only 3 chromosomal segments from Nipponbare. The quantitative trait loci (QTLs) conferring pollen fertility and spikelet fertility were evaluated in Wuhan, Hubei and Lingshui, Hainan environments using the F2 and F3 segregation populations. A novel QTL responsible for pollen sterility was detected between microsatellite markers RM262 and RM475 on chromosome 2, which explained 13.9% of the phenotypic variation. This QTL originated from the japonica parent and was considered as a major factor for the semisterility of IL37.

摘 要利用一套以籼稻珍汕97B为背景的粳稻日本晴染色体片段代换系, 鉴定发现1个半不育的代换系。全基因组基因型分析表明, 该代换系仅含3个粳稻导入片段, 而其他遗传背景与珍汕97B相同。在湖北武汉和海南分别种植其衍生的F2和F3分离群体, 采用单标记分析和区间作图法分析花粉育性和小穗育性的数量性状位点(QTL), 结果表明, 该代换系的半不育性是第2染色体上的粳稻导入片段引起的, 该片段RM262∼RM475区间存在1个新的影响花粉育性的QTL, 其贡献率为13.9%。研究结果将为进一步精细定位水稻育性QTL以及鉴定相关功能基因提供重要的试验基础。