Mapping quantitative trait loci (QTLs) for seedling-vigor using recombinant inbred lines of rice (Oryza sativa L.)
Mapping quantitative trait loci (QTLs) for seedling-vigor using recombinant inbred lines of rice (Oryza sativa L.)
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DOI：
10.1016/j.fcr.2004.06.004
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发表时间：
2005-02
影响因子：
5.8
通讯作者：
Zhihong Zhang;Si-Bin Yu;Ting Yu;Zheng Huang;Ying-guo Zhu
中科院分区：
文献类型：
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作者：
Zhihong Zhang;Si-Bin Yu;Ting Yu;Zheng Huang;Ying-guo Zhu
秧苗活力对水稻种植制度中的最佳林分建立和提高杂草竞争能力具有重要意义。以Lemont（粳稻）与特青（籼稻）杂交获得的重组自交系为材料，采用纸卷法研究了3个与秧苗活力相关的性状：发芽率、苗长和干物质重。利用表型数据和由198个标记位点组成的连锁图，利用QTLMapper 1.0进行复合区间定位，同时定位水稻秧苗活力的主效和上位性QTL。共检测到13个主效QTL和19对R2≥ 5%的上位性位点。几乎所有这些QTL或互作仅能解释约5-10%的表型变异。这些主效应和上位性位点中的大多数（68%）聚集在7个染色体区域，每个区域跨越12- 28 cM（centi-Morgan），包含3个或更多的可检测位点。当可检测到多个苗势相关性状时，位于同一图位的主效QTL或上位性互作的加性效应或上位性效应方向相同，这与性状间的正相关性一致。结果表明，水稻幼苗活力受多个位点控制，多数位点的效应较小，但上位性效应作为一个遗传因素比QTL的主效应更为重要。沿着前人的研究结果，揭示了水稻幼苗活力的广泛遗传多样性。此外，位于第7染色体上的qSV-7对多个秧苗活力相关性状的主效应最大，可作为水稻秧苗活力育种的分子标记辅助选择的潜在目标。
Seedling-vigor is important for optimum stand establishment and increasing weed competitive ability in rice cropping systems. In the current study, three seedling-vigor-related traits, seed germination rate, seedling shoot length and dry matter weight, were investigated by the paper-roll tests with rice recombinant inbred lines derived from a cross between Lemont (japonica) and Teqing (indica). The phenotype data, together with a linkage map consisting of 198 marker loci, was used to conduct composite interval mapping by QTLMapper 1.0 to simultaneously map both main-effect and epistatic QTLs for seedling-vigor in rice. Totally, 13 putative main-effect QTLs and 19 pairs of epistatic loci with R2≥ 5% were identified. Almost all of these QTLs or interactions individually explained only around 5–10% of the phenotypic variation. The majority (68%) of these main-effect and epistatic loci were clustered in seven chromosome regions, each spanning 12–28cM (centi-Morgan) and containing three or more detectable loci. When detectable for the multiple seedling-vigor-related traits, either the main-effect QTLs or the epistatic interactions sharing the same map location had their additive or epistatic effects in the same direction, which agreed well with the positive correlations among the traits. The results demonstrated that seedling-vigor in rice could be controlled by many loci, most of which had small effects, but, relatively, epistasis as a genetic factor was much more important than main-effects of QTLs. Along with the results reported previously, this study revealed the extensive genetic diversity for seedling-vigor in rice. In addition, the QTL qSV-7on chromosome 7 was found to have the largest main-effects on multiple seedling-vigor-related traits and therefore could be used as a potential target to be genetically manipulated by marker-assisted selection in rice seedling-vigor breeding programs.