A large-scale screen for artificial selection in maize identifies candidate agronomic loci for domestication and crop improvement
A large-scale screen for artificial selection in maize identifies candidate agronomic loci for domestication and crop improvement
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DOI：
10.1105/tpc.105.037242
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发表时间：
2005-11-01
期刊：
影响因子：
11.6
通讯作者：
McMullen, MD
中科院分区：
文献类型：
--
作者：
Yamasaki, M;Tenaillon, MI;McMullen, MD
玉米（Zea mays subsp mays）是从大刍草（Z. mays subsp parviglumis）在6000年到9000年前在墨西哥南部通过单一驯化事件。这一驯化事件产生了原始的玉米地方品种，这些品种被美洲原住民传播到整个美洲，并适应了广泛的环境条件。从地方品种开始，世纪植物育种家选择玉米自交系用于杂交玉米生产。驯化和作物改良都涉及在控制关键形态和农艺性状的基因上选择特定的等位基因，导致相对于转基因的遗传多样性减少。在这里，我们从14个自交系的样本中测序了1095个玉米基因，并选择了35个序列多样性为零的基因作为潜在的选择目标。这35个基因，然后在不同的玉米地方品种和大刍草样本测序和测试选择。使用两个统计测试，我们确定了八个候选基因。这八个候选基因座的扩展基因测序证实，在整个基因中有六个被选择，其余两个在每个基因的39个部分中表现出选择的证据。所选择的基因具有与营养品质、成熟度和生产力的农艺选择一致的功能。我们的大规模筛选人工选择允许识别潜在的农学重要性的基因，即使基因功能和感兴趣的表型是未知的。
Maize (Zea mays subsp mays) was domesticated from teosinte (Z. mays subsp parviglumis) through a single domestication event in southern Mexico between 6000 and 9000 years ago. This domestication event resulted in the original maize landrace varieties, which were spread throughout the Americas by Native Americans and adapted to a wide range of environmental conditions. Starting with landraces, 20th century plant breeders selected inbred lines of maize for use in hybrid maize production. Both domestication and crop improvement involved selection of specific alleles at genes controlling key morphological and agronomic traits, resulting in reduced genetic diversity relative to unselected genes. Here, we sequenced 1095 maize genes from a sample of 14 inbred lines and chose 35 genes with zero sequence diversity as potential targets of selection. These 35 genes were then sequenced in a sample of diverse maize landraces and teosintes and tested for selection. Using two statistical tests, we identified eight candidate genes. Extended gene sequencing of these eight candidate loci confirmed that six were selected throughout the gene, and the remaining two exhibited evidence of selection in the 39 portion of each gene. The selected genes have functions consistent with agronomic selection for nutritional quality, maturity, and productivity. Our large-scale screen for artificial selection allows identification of genes of potential agronomic importance even when gene function and the phenotype of interest are unknown.