Perales Hugo, Golicher Duncan
El Colegio de la Frontera Sur, Grupo de Agroecología, Carretera Panamericana y Periférico Sur s/n, San Cristóbal, Chiapas, Mexico.
El Colegio de la Frontera Sur, Grupo Conservación y Restauración de Bosques, Carretera Panamericana y Periférico Sur s/n, San Cristóbal, Chiapas, Mexico; Center for Conservation Ecology & Environmental Change, School of Applied Sciences, Bournemouth University, Dorset, United Kingdom.
PLoS One. 2014 Dec 8;9(12):e114657. doi: 10.1371/journal.pone.0114657. eCollection 2014.
Traditional landraces of maize are cultivated throughout more than one-half of Mexico's cropland. Efforts to organize in situ conservation of this important genetic resource have been limited by the lack of knowledge of regional diversity patterns. We used recent and historic collections of maize classified for race type to determine biogeographic regions and centers of landrace diversity. We also analyzed how diversity has changed over the last sixty years. Based on racial composition of maize we found that Mexico can be divided into 11 biogeographic regions. Six of these biogeographic regions are in the center and west of the country and contain more than 90% of the reported samples for 38 of the 47 races studied; these six regions are also the most diverse. We found no evidence of rapid overall decline in landrace diversity for this period. However, several races are now less frequently reported and two regions seem to support lower diversity than in previous collection periods. Our results are consistent with a previous hypothesis for diversification centers and for migration routes of original maize populations merging in western central Mexico. We provide maps of regional diversity patterns and landrace based biogeographic regions that may guide efforts to conserve maize genetic resources.
传统的玉米地方品种种植面积占墨西哥农田总面积的一半以上。由于缺乏对区域多样性模式的了解，对这一重要遗传资源进行原地保护的努力受到了限制。我们利用近期和历史上按种族类型分类的玉米样本，来确定生物地理区域和地方品种多样性中心。我们还分析了过去六十年来多样性是如何变化的。基于玉米的种族构成，我们发现墨西哥可分为11个生物地理区域。其中6个生物地理区域位于该国中部和西部，包含了所研究的47个种族中38个种族报告样本的90%以上；这6个区域也是多样性最高的地区。我们没有发现这一时期地方品种多样性总体快速下降的证据。然而，现在有几个种族的报告频率较低，而且有两个区域的多样性似乎比之前的采集时期有所降低。我们的结果与之前关于墨西哥中西部原始玉米种群多样化中心和迁移路线的假设一致。我们提供了区域多样性模式图以及基于地方品种的生物地理区域图，这些图可能会为玉米遗传资源的保护工作提供指导。
