Evidence from Genome-wide Simple Sequence Repeat Markers for a Polyphyletic Origin and Secondary Centers of Genetic Diversity of Brassica juncea in China and India
Evidence from Genome-wide Simple Sequence Repeat Markers for a Polyphyletic Origin and Secondary Centers of Genetic Diversity of Brassica juncea in China and India
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DOI：
10.1093/jhered/est015
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发表时间：
2013-05-01
影响因子：
3.1
通讯作者：
Cowling, Wallace A.
中科院分区：
文献类型：
--
作者：
Chen, Sheng;Wan, Zhenjie;Cowling, Wallace A.
芥蓝是印度和中国栽培历史悠久的重要粮食作物。以前的研究表明芥菜的多系起源，以及从初级多样性中心到次级多样性中心的不止一次迁徙。利用99个简单序列重复标记对来自中国、印度、欧洲和澳大利亚的119个油菜品种的分子遗传多样性进行了研究，以检验分子分化是否遵循瓦维洛夫提出的印度和中国次级多样性中心的观点。A基因组中的标记识别出两个不同的组，而B基因组中的标记证实了相同的两组。第1组包括来自印度中部和西部的材料，以及来自东部中国的材料。第2组包括来自中西部的中国以及来自印度北部和东部的材料。欧洲和澳大利亚种质仅存在于第2组，中国种质的等位基因多样性(第1组)高于印度种质(第1组)，每个加入组(第1组和第2组)的私有等位基因也多于印度种质。组1和组2的标记数据和地理分布与芥菜的两次独立迁徙是一致的，即从其起源中心中东和邻近地区沿贸易路线迁徙到中国西部和印度北部，然后进行区域适应。与组2相比，组1在印度向南和向西迁移，在中国向东迁移。组2表现出不同的农业生态适应，在中国中西部有黄种春播类型，在印度有棕种秋播类型。
The oilseed Brassica juncea is an important crop with a long history of cultivation in India and China. Previous studies have suggested a polyphyletic origin of B. juncea and more than one migration from the primary to secondary centers of diversity. We investigated molecular genetic diversity based on 99 simple sequence repeat markers in 119 oilseed B. juncea varieties from China, India, Europe, and Australia to test whether molecular differentiation follows Vavilov's proposal of secondary centers of diversity in India and China. Two distinct groups were identified by markers in the A genome, and the same two groups were confirmed by markers in the B genome. Group 1 included accessions from central and western India, in addition to those from eastern China. Group 2 included accessions from central and western China, as well as those from northern and eastern India. European and Australian accessions were found only in Group 2. Chinese accessions had higher allelic diversity per accession (Group 1) and more private alleles per accession (Groups 1 and 2) than those from India. The marker data and geographic distribution of Groups 1 and 2 were consistent with two independent migrations of B. juncea from its center of origin in the Middle East and neighboring regions along trade routes to western China and northern India, followed by regional adaptation. Group 1 migrated further south and west in India, and further east in China, than Group 2. Group 2 showed diverse agroecological adaptation, with yellow-seeded spring-sown types in central and western China and brown-seeded autumn-sown types in India.