磷素缺乏限制作物产量的提高,水稻低磷胁迫下根系伸长性状的遗传研究,对选育耐低磷品种具有指导意义。利用一套以9311为遗传背景携带日本晴置换片段的染色体片段置换系为材料,对低磷胁迫下水稻苗期主根伸长性状及相对性状进行了QTL定位。结果表明,两亲本及置换系群体对低磷反应存在明显差异。共定位到9个QTLs,其中正常水平下2个,低磷胁迫水平下4个以及3个相对性状QTLs。9个QTLs中有5个QTLs的加性效应值为负,效应来源于低磷敏感亲本日本晴,其余4个QTLs的加性效应值为正,效应来源于耐低磷亲本9311。在低磷根长和相对性状中共同检测到一个QTL,位于水稻第5染色体上,该位点没有磷相关QTL的报道。以上结果将为准确鉴定水稻耐低磷胁迫的遗传位点及分子标记辅助选育耐性品种提供依据。 Phosphorus deficiency can limit the yield of crops and the inheritance of root elongation traits in rice under low-P stress can guide the selection of low-phosphorus-tolerant cultivars. In this study, QTL mapping of elongation traits and relative traits of main roots of rice seedlings under low-phosphorus stress was carried out using a chromosomal segment substitution line carrying the Nipponbare fragment with 9311 as the genetic background. The results showed that there was a significant difference in the response of low-phosphorus between the parents and the substitution lines. A total of nine QTLs were mapped, including two at normal level, four at QTL level and three QTLs with relative traits. Five of the 9 QTLs had negative additive effects, which were derived from Nipponbare, a low-phosphorus sensitive parent. The additive effects of the remaining 4 QTLs were positive and their effects were derived from 9311 low-phosphorus tolerant parents. A common QTL detected in the low-phosphorus root length and relative traits was located on rice chromosome 5, and no phosphorus-related QTL was reported at this locus. The above results will provide the basis for the accurate identification of the genetic loci and marker-assisted selection of tolerance to rice stress.