Mapping quantitative trait loci for seedling vigor in rice using RFLPs
Mapping quantitative trait loci for seedling vigor in rice using RFLPs
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DOI：
10.1007/bf00223685
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发表时间：
1996-03-01
影响因子：
5.4
通讯作者：
Mackill, DJ
中科院分区：
文献类型：
--
作者：
Redona, ED;Mackill, DJ
提高幼苗活力是现代水稻 (Oryza sativa L.) 育种计划的一个重要目标。本研究的目的是利用限制性片段长度多态性（RFLP）来识别和绘制与幼苗活力相关性状相关的数量性状位点（QTL）。由 204 株植物组成的 F-2 群体是由低活力粳稻品种“Labelle”(LBL) 和高活力籼稻品种“Black Gora”(BG) 杂交培育而成。连锁图谱由 117 个标记构建，跨越 1496 Haldane cM，涵盖 12 条水稻染色体，平均标记间距为 14 cM。在两种温度（18 摄氏度和 25 摄氏度）下进行的斜板测试中，测量了 F-3 家族的芽、根、胚芽鞘和中胚轴的长度。通过区间分析，在对数似然 (LOD) 阈值为 2.5 的两个温度范围内鉴定并绘制了 13 个 QTL（每个 QTL 占表型方差的 7% 至 38%）。 4 个 QTL 控制芽长度，2 个 QTL 各控制根和胚芽鞘长度，5 个 QTL 影响中胚轴长度。单点分析证实了这些 QTL 的存在，并检测了芽、根和胚芽鞘长度的其他基因座，后者通常占表型变异的不到 5%。通过区间分析和单点分析仅检测到 3 个 QTL 在两种温度条件下均得到表达。观察到基因作用的加性、显性和超显性模式。与亲本表型的预测相反，低活力 LBL 贡献了阳性等位基因 fdr 芽、根和胚芽鞘长度的 46%。来自高活力亲本 BG 的阳性等位基因被鉴定为增加根、胚芽鞘和中胚轴长度。然而，BG 贡献的等位基因对芽长只有很小的影响，而芽长是水播种水稻幼苗活力最重要的决定因素，这表明 BG 不是将更快的芽生长等位基因引入温带粳稻品种的理想供体亲本。
Improving seedling vigor is an important objective of modern rice (Oryza sativa L.) breeding programs. The purpose of this study was to identify and map quantitative trait loci (QTL) underlying seedling vigor-related traits using restriction fragment length polymorphisms (RFLPs). An F-2 population of 204 plants was developed from a cross between a low-vigor japonica cultivar 'Labelle' (LBL) and a high-vigor indica cultivar 'Black Gora' (BG). A linkage map was constructed of 117 markers spanning 1496 Haldane cM and encompassing the 12 rice chromosomes with an average marker spacing of 14 cM. The length of the shoots, roots, coleoptile and mesocotyl were measured on F-3 families in slantboard tests conducted at two temperatures (18 degrees and 25 degrees C). By means of interval analysis, 13 QTLs, each accounting for 7% to 38% of the phenotypic variance, were identified and mapped in the two temperature regimes at a log-likelihood (LOD) threshold of 2.5. Four QTLs controlled shoot length, 2 each controlled root and coleoptile lengths and 5 influenced mesocotyl length. Single-point analysis confirmed the presence of these QTLs and detected additional loci for shoot, root and coleoptile lengths, these latter usually accounting for less than 5% of the phenotypic variation. Only 3 QTLs detected both by interval and single-point analyses were expressed under both temperature regimes. Additive, dominant and overdominant modes of gene action were observed. Contrary to what was predicted from parental phenotype, the low-vigor LBL contributed 46% of the positive alleles fdr shoot, root and coleoptile lengths. Positive alleles from the high-vigor parent BG were identified for increased root, coleoptile and mesocotyl lengths. However, BG contributed alleles with only minor effects for shoot length, the most important determinant of seedling vigor in water-seeded rice, suggesting that it would not be an ideal donor parent for introducing faster shoot growth alleles into temperate japonica cultivars.