水稻光合功能相关性状QTL分析

QTL Analysis for Traits Associated with Photosynthetic Functions in Rice (Oryza sativa L.)

利用粳稻Kinmaze/籼稻DV85杂交后代单粒传衍生的81个F11家系所组成的重组自交系(RecombinantInbredLines,RILs)群体,研究水稻光合功能相关性状的数量性状基因座(QTL)。在水稻抽穗后7d测定叶片全氮含量(TLN)、叶绿素a/b比值(Chl.a∶b)和叶绿素含量(Chl)。共检测到6个QTL,各QTL的LOD值为2.66～4.81,贡献率为11.2%～29.6%,其中,在第1、2和11染色体上检测到3个与全氮含量相关的QTL,相应贡献率为17.3%、15.3%、13.7%;在第3和4染色体检测到2个与叶绿素a/b比值相关的QTL,贡献率为13.8%和29.6%;在第1染色体检测到1个与叶绿素含量相关的QTL,贡献率为11.2%。4个QTL为本研究新检测的基因座。有趣的是,控制叶绿素含量的qCC1位于第1染色体上RFLP标记C122附近,与已报道的NADH谷氨酸合成酶基因位置一致,而叶绿素合成始于谷氨酸,暗示该基因座与水稻光合功能关系极为密切。然而,对抽穗后30d叶绿素含量进行QTL分析,结果未检测到与其相关的QTL,表明控制叶绿素含量qCC1效应随水稻叶片的衰老而降低。

A mapping population of 81 F11 lines （Recombinant Inbred Lines,RILs）,derived from a cross between a japonica variety Kinmaze and an indica variety DV85 by single-seed descent method,was used to detect quantitative trait loci （QTL） for traits associated with photosynthetic functions. Total leaf nitrogen content （TLN） ,chlorophyll a/b ratio （Chl. a： b） and chlorophyll content（ Chl）were measured in leaves of rice （Oryza sativa L. ） at the 7th day after heading. A total of six putative QTLs were detected with percentage of variance explained （PVE） ranging between 11.2% -29.6% ,and LODof QTLs 2. 66 - 4. 81. Of those putative QTLs,three for TLN were detected on chromosomes 1 ,2 and 11 ,with PVE of 17.3% ,15.3% and 13.7% ,respectively;Two controlling Chl. a：b on chromosomes 3 and 4 ,PVE of 13. 8% and 29.6% ,one for Chl on chromosome 1, PVE of 11.2%. Four of those detected QTLs were newly reported in this study. Interestingly,the QTL controlling chlorophyll content,namely qCC-1 reported here,was detected in the region of the RFLP marker C122 on chromosome 1 ,where harbored NADH-glutamate synthase structure gene according to a previous study. Because the biosynthesis of chlorophyll begins with glutamate, qCC-1 would play a vital role in photosynthetic functions. Whereas,no QTL controlling chlorophyll content were detected at the 30th day after heading, suggesting that the effect of the QTL controlling chlorophyll content decreased during leaf senescence.