Molecular diversity and association mapping of fiber quality traits in exotic G. hirsutum L. germplasm
Molecular diversity and association mapping of fiber quality traits in exotic G. hirsutum L. germplasm
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DOI：
10.1016/j.ygeno.2008.07.013
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发表时间：
2008-12-01
期刊：
影响因子：
4.4
通讯作者：
Abdukarimov, A.
中科院分区：
文献类型：
--
作者：
Abdurakhmonov, I. Y.;Kohel, R. J.;Abdukarimov, A.
栽培棉种质资源遗传基础狭窄，阻碍了世界范围内棉花生产力的提高。虽然潜在的遗传多样性存在于棉属，它在很大程度上是“利用不足”，由于光周期和缺乏创新的工具来克服这些挑战。应用连锁不平衡（LD）为基础的关联作图是一个替代的强大的分子工具，剖析和利用棉花种质资源中保存的自然遗传多样性，大大加快仍然“滞后”的棉花标记辅助选择（MAS）计划。然而，棉花全基因组连锁不平衡（LD）的程度尚未确定。我们报告的程度全基因组LID和纤维品质性状的关联映射，使用95个核心微卫星标记在285个外来陆地棉加入，包括208个地方品种股票和77个光周期品种加入。我们证明了在外来棉花种质内存在有用的遗传多样性。在该种质集中，11-12%的SSR位点对显示出显著的LD。在显著性阈值处，LD的全基因组平均值在品种种质的遗传距离30 cM内下降。在r（2）>= 0.2时，全基因组LD在地方品种种质中平均降低到1-2 cM，在品种种质中降低到6-8 cM，这为棉花重要农艺性状的关联作图提供了证据。我们观察到显着的群体结构和相关性分析种质。因此，混合线性模型（MLM）的应用，同时考虑亲缘关系（K）和群体结构（Q）检测到6%和13%的SSR标记与棉花的主要纤维品质性状。研究结果首次揭示了关联作图的可行性和潜力，并考虑了棉花种质资源中存在的群体结构和分层现象。棉花种质资源中与纤维品质性状相关的SSR标记数量广泛涵盖了许多历史减数分裂事件，应有助于利用MAS程序有效地开发潜在的新的遗传变异。(C)2008年爱思唯尔公司All rights reserved.
The narrow genetic base of cultivated cotton germplasm is hindering the cotton productivity worldwide. Although potential genetic diversity exists in Gossypium genus, it is largely 'underutilized' due to photoperiodism and the lack of innovative tools to overcome such challenges. The application of linkage disequilibrium (LD)-based association mapping is an alternative powerful molecular tool to dissect and exploit the natural genetic diversity conserved within cotton germplasm collections, greatly accelerating still 'lagging' cotton marker-assisted selection (MAS) programs. However, the extent of genome-wide linkage disequilibrium (LD) has not been determined in cotton. We report the extent of genome-wide LID and association mapping of fiber quality traits by using a 95 core set of microsatellite markers in a total of 285 exotic Gossypium hirsutum accessions, comprising of 208 landrace stocks and 77 photoperiodic variety accessions. We demonstrated the existence of useful genetic diversity within exotic cotton germplasm. In this germplasm set, 11-12% of SSR loci pairs revealed a significant LD. At the significance threshold a genome-wide average of LD declines within the genetic distance at 30 cM in variety germplasm. Genome wide LD at r(2) >= 0.2 was reduced on average to similar to 1-2 cM in the landrace stock germplasm and 6-8 cM in variety germplasm, providing evidence of the potential for association mapping of agronomically important traits in cotton. We observed significant population structure and relatedness in assayed germplasm. Consequently, the application of the mixed liner model (MLM), considering both kinship (K) and population structure (Q) detected between 6% and 13% of SSR markers associated with the main fiber quality traits in cotton. Our results highlight for the first time the feasibility and potential of association mapping, with consideration of the population structure and stratification existing in cotton germplasm resources. The number of SSR markers associated with fiber quality traits in diverse cotton germplasm, which broadly covered many historical meiotic events, should be useful to effectively exploit potentially new genetic variation by using MAS programs. (C) 2008 Elsevier Inc. All rights reserved.