Linkage mapping of root shape traits in two carrot populations
Linkage mapping of root shape traits in two carrot populations
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DOI：
10.1093/g3journal/jkae041
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发表时间：
2024-02
期刊：
影响因子：
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通讯作者：
Andrey Vega;S. Brainard;Irwin L Goldman
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文献类型：
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作者：
Andrey Vega;S. Brainard;Irwin L Goldman
摘要利用复合区间作图法对胡萝卜两个双亲群体（n = 119和n = 128）根形性状的遗传基础进行了研究。胡萝卜F2：3后代的根生长超过2年，并使用数字成像管道进行分析以提取组成市场类别的根表型。根性状的广义遗传力在0.46 ~ 0.80之间。在两个群体的第2和第6染色体上鉴定了可重复的数量性状位点（QTL）。还观察到与表型相关的根性状的QTL的共定位，并与先前在已发表的关联和连锁作图研究中确定的QTL相吻合。单个QTL解释了性状间总表型变异的14%至27%，而4个长宽比QTL共同解释了高达73%的变异。在QTL支持区间内鉴定了与OFP-TRM（OVATE家族蛋白-TONNEAU 1募集基序）和IQD（IQ 67结构域）途径相关的预测基因。这一观察结果提出了扩展目前的水果形状的调节子模型，包括胡萝卜贮藏根的可能性。然而，这一途径在根中以起源于形成层的次生生长为特征的精确分子机制仍然未知。
Abstract This study investigated the genetic basis of carrot root shape traits using composite interval mapping in two biparental populations (n = 119 and n = 128). The roots of carrot F2:3 progenies were grown over 2 years and analyzed using a digital imaging pipeline to extract root phenotypes that compose market class. Broad-sense heritability on an entry-mean basis ranged from 0.46 to 0.80 for root traits. Reproducible quantitative trait loci (QTL) were identified on chromosomes 2 and 6 on both populations. Colocalization of QTLs for phenotypically correlated root traits was also observed and coincided with previously identified QTLs in published association and linkage mapping studies. Individual QTLs explained between 14 and 27% of total phenotypic variance across traits, while four QTLs for length-to-width ratio collectively accounted for up to 73% of variation. Predicted genes associated with the OFP-TRM (OVATE Family Proteins—TONNEAU1 Recruiting Motif) and IQD (IQ67 domain) pathway were identified within QTL support intervals. This observation raises the possibility of extending the current regulon model of fruit shape to include carrot storage roots. Nevertheless, the precise molecular mechanisms through which this pathway operates in roots characterized by secondary growth originating from cambium layers remain unknown.