Multiple introgression events surrounding the Hd1 flowering-time gene in cultivated rice, Oryza sativa L.
Multiple introgression events surrounding the Hd1 flowering-time gene in cultivated rice, Oryza sativa L.
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DOI：
10.1007/s00438-010-0555-2
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发表时间：
2010-08-01
影响因子：
3.1
通讯作者：
Matsumoto, Takashi
中科院分区：
文献类型：
--
作者：
Fujino, Kenji;Wu, Jianzhong;Matsumoto, Takashi
开花时间是作物在当地适应的一个主要决定因素。Hd1是水稻开花时间的关键基因，与拟南芥CONSTANS基因同源。为了阐明Hd1在选择中的作用，我们检测了来自亚洲所有地区的60个亚洲栽培水稻（Oryza sativa L.）的Hd1等位基因，这些水稻包括籼稻、粳稻和黑稻三个栽培类群。所鉴定的等位基因可分为4个等位基因群。等位基因I和II组的Hd1功能等位基因分别对应于籼稻和粳稻。这些群体的非功能性等位基因与品种群体或地理位置的关联不明显。等位基因组III和IV对应于aus品种组。利用Hd1周围1.1 Mb的14个区域的单倍型模式和Hd1周围1.4和4.4 Mb的两个位点的psnine模式，采用聚结法对Hd1分子进化进行了鉴定。单倍型分析清楚地表明，Hd1等位基因迁移是由栽培群体间多重、复杂的遗传渗入事件引起的。野生稻稻Hd1单倍型在几十份材料中存在着强烈的分化，只有两个单倍型簇与栽培稻的Hd1单倍型簇有密切的亲缘关系。这有力地表明，除了驯化开始时的主要选择步骤外，多重渗入事件在适应的形成和多样化中发挥了重要作用。
Flowering time is a major determinant for the local adaptation of crops. Hd1 is a key flowering-time gene in rice and is orthologous to the Arabidopsis CONSTANS gene. To elucidate the role of Hd1 in selection, we examined the Hd1 alleles of 60 landraces of Asian cultivated rice (Oryza sativa L.) originating from all regions of Asia, which comprised three cultivar groups, indica, japonica, and aus. The identified alleles were classified into four allele groups. The functional Hd1 alleles in allele groups I and II corresponded to indica and japonica, respectively. Non-functional alleles in these groups were not clearly associated with cultivar groups or locations. Allele groups III and IV corresponded to the aus cultivar group. The ancestry of each cultivar group was identified by the coalescent approach for Hd1 molecular evolution using the haplotype patterns of 14 regions over the 1.1 Mb chromosomal region surrounding Hd1 and the pSINE patterns of two loci, 1.4 and 4.4 Mb apart from Hd1. The haplotype patterns clearly revealed that Hd1 allele migration was caused by multiple and complex introgression events between cultivar groups. The Hd1 haplotypes among dozens of accessions of the wild species O. rufipogon were strongly divergent and only two of the haplotype clusters in O. rufipogon were closely related to those in cultivated rice. This strongly suggested that multiple introgression events have played an important role in the shaping and diversification of adaptation in addition to primary selection steps at the beginning of domestication.