Centro de Biotecnología y Genómica de Plantas, E. T. S. I. Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón (Madrid), Spain.
PLoS One. 2011;6(12):e28715. doi: 10.1371/journal.pone.0028715. Epub 2011 Dec 6.
Management of wild peppers in Mexico has occurred for a long time without clear phenotypic signs of domestication. However, pre-domestication management could have implications for the population's genetic richness. To test this hypothesis we analysed 27 wild (W), let standing (LS) and cultivated (C) populations, plus 7 samples from local markets (LM), with nine polymorphic microsatellite markers. Two hundred and fifty two alleles were identified, averaging 28 per locus. Allele number was higher in W, and 15 and 40% less in LS and C populations, respectively. Genetic variation had a significant population structure. In W populations, structure was associated with ecological and geographic areas according to isolation by distance. When LM and C populations where included in the analysis, differentiation was no longer apparent. Most LM were related to distant populations from Sierra Madre Oriental, which represents their probable origin. Historical demography shows a recent decline in all W populations. Thus, pre-domestication human management is associated with a significant reduction of genetic diversity and with a loss of differentiation suggesting movement among regions by man. Measures to conserve wild and managed populations should be implemented to maintain the source and the architecture of genetic variation in this important crop relative.
墨西哥对野生辣椒的管理由来已久，但没有明显的驯化表型特征。然而，驯化前的管理可能对种群的遗传丰富度产生影响。为了验证这一假设，我们分析了 27 个野生（W）、自然生长（LS）和栽培（C）种群，以及 7 个来自当地市场（LM）的样本，使用了 9 个多态性微卫星标记。共鉴定出 252 个等位基因，平均每个位点 28 个。W 种群的等位基因数量更高，LS 和 C 种群的等位基因数量分别减少了 15%和 40%。遗传变异存在显著的种群结构。在 W 种群中，结构与生态和地理区域有关，符合距离隔离。当将 LM 和 C 种群纳入分析时，分化不再明显。大多数 LM 与来自东马德雷山脉的遥远种群有关，这表明它们可能是这些辣椒的起源地。历史人口动态显示，所有 W 种群的数量都在最近减少。因此，驯化前的人类管理与遗传多样性的显著减少有关，并导致分化丧失，这表明人类在不同地区之间的迁徙。应该采取措施保护野生和管理种群，以维持这一重要作物相关的遗传变异的来源和结构。
