Quantitative trait loci analysis of endosperm color and carotenoid content in sorghum grain
Quantitative trait loci analysis of endosperm color and carotenoid content in sorghum grain
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DOI：
10.2135/cropsci2007.12.0684
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发表时间：
2008-09-01
期刊：
影响因子：
2.3
通讯作者：
Kresovich, Stephen
中科院分区：
文献类型：
--
作者：
Fernandez, Maria G. Salas;Hamblin, Martha T.;Kresovich, Stephen
在非洲和亚洲的半干旱地区，维生素A缺乏症影响着大约2.5亿人，而高粱（Sorghum bicolor Moench）是主要的主食作物。黄色胚乳高粱含有类胡萝卜素，其中一些可被人类转化为维生素A。我们的目的是研究高粱胚乳中类胡萝卜素水平变异的遗传基础，通过定位与类胡萝卜素含量和胚乳颜色相关的数量性状位点（QTL），作为类胡萝卜素浓度的推定预测因子。2005年，在两个地点评估了由黄色胚乳（“KS 115”）与白色胚乳（“Macia”）亲本杂交开发的重组近交系群体。利用包括9个类胡萝卜素候选基因在内的112个分子标记构建了遗传图谱。叶黄素、玉米黄质和β-胡萝卜素是鉴定的主要类胡萝卜素。几个QTL检测到每个化合物以及颜色和总类胡萝卜素。颜色与所有化合物的水平显著相关，颜色QTL与类胡萝卜素QTL共定位。对于β-胡萝卜素（维生素原A），5个QTL定位于染色体1，2和10。其中之一，在2号染色体上，在两种环境下都是稳定的，有积极的加性效应（1.179和1.379），解释了大比例的表型方差（11.6%和15.15%），并与一个新的八氢番茄红素合酶基因（Psy 3）。本研究首次报道了高粱籽粒类胡萝卜素含量的QTL，为选育高维生素A原高粱提供了基础。
Vitamin A deficiency affects approximately 250 million people in semiarid regions of Africa and Asia, where sorghum (Sorghum bicolor Moench) is a major staple crop. Yellow endosperm sorghums contain carotenoids, some of which can be transformed by humans into vitamin A. Our objective was to study the genetic basis of variation in carotenoid levels in sorghum endosperm by mapping quantitative trait loci (QTL) associated with carotenoid content and endosperm color, as a putative predictor of carotenoid concentration. A recombinant inbred line population developed from a yellow ('KS115') by a white endosperm ('Macia') parental cross was evaluated in two locations in 2005. A genetic map was generated using 112 molecular markers including nine carotenoid candidate genes. Lutein, zeaxanthin, and beta-carotene were the major carotenoids identified. Several QTL were detected for each compound as well as for color and total carotenoids. Color was significantly correlated with the levels of all compounds, and color QTL co-localized with carotenoid QTL. For beta-carotene (provitamin A), five QTL were localized on chromosomes 1, 2, and 10. One of them, on chromosome 2, was stable across both environments, had positive additive effects (1.179 and 1.379), explained large proportions of the phenotypic variance (11.6% and 15.15%), and was associated with a new phytoene synthase gene (Psy3). This first report of QTL for carotenoid content in sorghum grain provides a starting point for breeding high-provitamin A sorghums.