利用重组自交系群体检测水稻耐铝毒数量性状基因座

Mapping of Quantitative Trait Loci Associated with Aluminum Tolerance in Rice (Oryza sativa L.) Using Recombinant Inbred Line s

利用Kinmaze DV85 81个重组自交家系(RIL)作图群体,采用苗期单营养液水培鉴定方法,以相对根伸长量(RRE)作为耐铝毒性状的表型值,分析亲本和重组自交系群体对铝毒的耐性表现。利用WindowsQTLCartographer1 13a软件共检测到5个耐铝毒QTLs ,分别位于第1、5、8、9和11染色体上,各个QTL的贡献率在8 6 4 %～18 6 0 %之间,其中,位于第5、8和11染色体上的QTLs对铝毒的抗性基因来自亲本DV85 ,位于第1和9染色体上的QTLs对铝毒的抗性基因来自亲本Kinmaze。结合前人研究结果,讨论了稳定表达的耐铝毒基因座,为进一步开展水稻耐铝毒分子标记辅助选择育种和耐铝毒基因的图位克隆奠定了基础。

Aluminum toxicity is one of the m ain factors limiting the productivity of crop plants in acid soils, particularly in the tropics and subtropics. In this study, a mapping population of 81 F 11 lines (recombinant inbred lines, RILs), derived from a cross between a ja ponica cultivar Kinmaze and an indica cultivar DV85 by the single-seed de scen t methods, was used to detect quantitative trait loci (QTLs) for Aluminum tolera nce. Aluminum tolerance was detected with relative root length (RRL) and relati ve root elongation (RRE) in two cultivars (Asominori and IR24) of rice. Results indicated that RRE is a parameter more directly related to Al tolerance and con venient in use than RRL. Furthermore, RRE of seedlings which grew on nets float ing on 0.5 mmol/L CaCl 2 (pH 4.5) solution with or without Al stress, was us ed to evaluated for the Al toxicity tolerance of RILs and the parents at seedlin g stage. QTL analysis was performed with Windows QTL Cartographer 1.13a progra m by composite interval mapping, as the result, five QTLs controlling aluminum t oxicity tolerance were detected on chromosomes 1, 5, 8, 9 and 11, respectively. Individual QTL accounted for 8.64%-18.60% of the phenotypic variation in the RIL population. In the five QTLs, Kinmaze contributed favorable alleles (les s impaired by stress) for qRRE1 and qRRE9, while DV85 contributed favorable alleles for qRRE5, qRRE8 and qRRE 11. Comparing with the other mapping results, QTLs, which mapped o n chromosomes 1, 8, 9 and 11, appeared to be consistent among different rice pop ulations. These QTLs would be highly useful for enhancing tolerance to Al toxic ity in marker-assisted selection (MAS) and breeding program and map-based clon ing of Al-tolerance genes.