Mapping quantitative trait loci associated with root penetration ability in rice (Oryza sativa L)
Mapping quantitative trait loci associated with root penetration ability in rice (Oryza sativa L)
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DOI：
10.1007/bf00226082
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发表时间：
1996-05-01
影响因子：
5.4
通讯作者：
Nguyen, HT
中科院分区：
文献类型：
--
作者：
Ray, JD;Yu, L;Nguyen, HT
根系渗透能力是影响水稻抗旱性的重要因素。然而，根穿透能力的育种受到与测量根性状相关的困难的抑制。我们的目的是确定限制性片段长度多态性（RFLPs）与根穿透能力。以石蜡-矿脂层作为压实土壤的预处理，对202个重组自交系在3个重复上的穿透层的垂直根轴数、垂直根轴总数和单株分蘖数进行了统计。作为根穿透能力的量度，我们使用根穿透指数，其定义为穿透蜡矿脂层的垂直根轴总数的百分比。RI群体的根轴数（10-115根）、根轴总数（74-226根）、单株分蘖数（6-18个）和根深指数（0.11-0.71）变化范围较大。采用单标记和区间数量性状分析方法，对与根深数、总根数、根深指数和分蘖数相关的RFLP位点进行了分析。其中4个QTL与根数相关，19个QTL与总根数相关，6个QTL与根深指数相关，10个QTL与分蘖数相关。通过回归分析，这些QTL分别解释了根数变异的8%、总根数变异的19%、根深指数变异的13%和分蘖数变异的14%。多标记回归模型占根系渗透指数变异的最大比例是一个三标记模型，占变异的34%。双标记模型解释了穿透根数变异的13%，总根数变异的25%，分蘖数变异的21%。这是第一篇应用RFLP数量性状分析技术剖析与总根数、根穿透力和分蘖数相关的遗传位点的研究论文。
Root penetration ability is an important factor for rice drought resistance in areas with soils subject to both compaction and periodic water deficits. However, breeding for root penetration ability is inhibited by the difficulties associated with measuring root traits. Our objective was to identify restriction fragment length polymorphisms (RFLPs) associated with root penetration ability. Using wax-petrolatum layers as a pr-oxy for compacted soil, we counted the number of vertical root axes penetrating through the layer, the total number of vertical root axes and the number of tillers per plant of 202 recombinant inbred (RI) lines over three replications. As a measure of root penetration ability, we used a root penetration index defined as the percent of the total number of vertical root axes that penetrated through a wax-petrolatum layer. The RI population exhibited a wide range in the number of penetrating roots axes (10-115 roots), the total number of roots axes (74-226 roots), tillers per plant (6-18), and in the root penetration index (0.11-0.71). Single-marker and interval quantitative trait analyses were conducted to identify RFLP loci associated with the number of penetrating roots, total root number, root penetration index, and tiller number. Four quantitative trait loci (QTLs) were associated with the number of penetrated roots, 19 with the total root number, six QTLs with the root penetration index and ten with tiller number. Individually, these QTLs accounted for a maximum of 8% of the variation in the number of penetrating roots, 19% of the variation in total root number, 13% of the variation in root penetration index and 14% of the variation in tiller number as estimated from regressions. The multi-marker regression model accounting for the greatest proportion of the variation in the root penetration index was a three-marker model that accounted for 34% of the variation. Two-marker models accounted for 13% of the variation in the number of penetrated roots, 25% of the variation in total root number, and 21% of the variation in tiller number. This is the first research paper to apply RFLP quantitative trait analysis to dissect genetic loci associated with the total number of roots, root penetration ability and tiller number.