Molecular mapping of QTLs conferring stay-green in grain sorghum (Sorghum bicolor L. Moench).
Molecular mapping of QTLs conferring stay-green in grain sorghum (Sorghum bicolor L. Moench).
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DOI：
10.1139/gen-43-3-461
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发表时间：
2000-06
期刊：
影响因子：
3.1
通讯作者：
Wenwei Xu;P. Subudhi;Oswald R. Crasta;D. Rosenow;John E. Mullet;Henry T. Nguyen
中科院分区：
文献类型：
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作者：
Wenwei Xu;P. Subudhi;Oswald R. Crasta;D. Rosenow;John E. Mullet;Henry T. Nguyen
抗旱性在作物生产中具有极其重要的意义。植物对干旱胁迫响应的遗传因子的确定为提高植物的耐旱性提供了坚实的基础。持绿性是高粱的一种抗旱性状。Moench），使植物在开花后阶段的严重土壤水分胁迫下抵抗早衰。本研究的目的是定位控制高粱持绿性和叶绿素含量的数量性状位点。利用限制性片段长度多态性（RFLP）图谱，从重组自交系（RIL）群体，我们确定了四个保绿QTL，位于三个连锁群。其中，Stg 1和Stg 2位于连锁群A上，Stg 3和Stg 4分别位于连锁群D和J上。两个保绿QTL Stg 1和Stg 2分别解释了13-20%和20-30%的表型变异，在两年的所有试验中一致地确定在不同地点。在花后干旱胁迫条件下，还发现了3个影响叶绿素含量的QTL（Chl 1、Chl 2和Chl 3），解释了25-30%的表型变异。这3个保绿QTL区域（Stg 1、Stg 2和Stg 3）占表型变异的46%。Stg 1和Stg 2区域还包含关键光合酶、热激蛋白和脱落酸（阿坝）响应基因的基因。这样的空间排列表明连锁群A对高粱的耐旱性和耐热性以及产量生产是重要的。高分辨率定位和克隆保绿性QTL有助于培育抗旱性强的杂交种，并有助于了解干旱诱导植物衰老的机理。
Drought resistance is of enormous importance in crop production. The identification of genetic factors involved in plant response to drought stress provides a strong foundation for improving drought tolerance. Stay-green is a drought resistance trait in sorghum (Sorghum bicolor L. Moench) that gives plants resistance to premature senescence under severe soil moisture stress during the post-flowering stage. The objective of this study was to map quantitative trait loci (QTLs) that control the stay-green and chlorophyll content in sorghum. By using a restriction fragment length polymorphism (RFLP) map, developed from a recombinant inbred line (RIL) population, we identified four stay-green QTLs, located on three linkage groups. The QTLs (Stg1 and Stg2) are on linkage group A, with the other two, Stg3 and Stg4, on linkage groups D and J, respectively. Two stay-green QTLs, Stg1 and Stg2, explaining 13-20% and 20-30% of the phenotypic variability, respectively, were consistently identified in all trials at different locations in two years. Three QTLs for chlorophyll content (Chl1, Chl2, and Chl3), explaining 25-30% of the phenotypic variability were also identified under post-flowering drought stress. All coincided with the three stay-green QTL regions (Stg1, Stg2, and Stg3) accounting for 46% of the phenotypic variation. The Stg1 and Stg2 regions also contain the genes for key photosynthetic enzymes, heat shock proteins, and an abscisic acid (ABA) responsive gene. Such spatial arrangement shows that linkage group A is important for drought- and heat-stress tolerance and yield production in sorghum. High-resolution mapping and cloning of the consistent stay-green QTLs may help to develop drought-resistant hybrids and to understand the mechanism of drought-induced senescence in plants.