低磷胁迫下水稻苗期根长性状的QTL定位

QTL Mapping for Root Elongation Traits Related to Phosphorus-deficiency Tolerance at Seedling Stage in Rice

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 is a major yield-limiting factor in crop production;studies about low phosphor-us tolerance will provide important theoretical guiding for rice resistant breeding .In this study ,a set of chromosome segment substitution lines carrying Nipponbare segments in 9311 background was used to identify QTLs for root e-longation traits related to phosphorus deficiency at rice seedling stage under solution conditions .A total of nine QTLs for three root elongation traits were mapped ,including two QTLs under normal phosphorus level ,four QTLs under low phosphorus stress level ,and three relative trait QTLs .Of them,additive effect values of five QTLs were negative , and derived from the low-phosphorus-sensitive parent Nipponbare .Additional four QTLs were of positive additive effect values and their effects were derived from the low-phosphorus-tolerance parent 9311 .One common QTL loca-ted on rice chromosome 5 was detected between the root elongation trait under low phosphorus level and relative trait,which was not reported previously .The results will provide information for identification of genetic loci associ-ated with low phosphorus tolerance and for rice marker-assisted breeding .