INRA, UMR 1098, Développement et Amélioration des Plantes (DAP), Bat, 3, Campus CIRAD TA A 96/03, Av, Agropolis, 34398 Montpellier Cedex 5, France.
BMC Plant Biol. 2010 Feb 18;10:28. doi: 10.1186/1471-2229-10-28.
Traditional agroecosystems are known to host both large crop species diversity and high within crop genetic diversity. In a context of global change, this diversity may be needed to feed the world. Are these agroecosystems museums (i.e. large core collections) or cradles of diversity? We investigated this question for a clonally propagated plant, fig (Ficus carica), within its native range, in Morocco, but as far away as possible from supposed centers of domestication.
Fig varieties were locally numerous. They were found to be mainly highly local and corresponded to clones propagated vegetatively. Nevertheless these clones were often sufficiently old to have accumulated somatic mutations for selected traits (fig skin color) and at neutral loci (microsatellite markers). Further the pattern of spatial genetic structure was similar to the pattern expected in natural population for a mutation/drift/migration model at equilibrium, with homogeneous levels of local genetic diversity throughout Moroccan traditional agroecosystems.
We conclude that traditional agroecosystems constitue active incubators of varietal diversity even for clonally propagated crop species, and even when varieties correspond to clones that are often old. As only female fig is cultivated, wild fig and cultivated fig probably constitute a single evolutionary unit within these traditional agroecosystems. Core collections, however useful, are museums and hence cannot serve the same functions as traditional agroecosystems.
传统的农业生态系统以拥有大量作物物种多样性和高作物内部遗传多样性而闻名。在全球变化的背景下，这种多样性可能是养活世界的需要。这些农业生态系统是多样性的“博物馆”（即大型核心收藏）还是多样性的“摇篮”？我们在摩洛哥的原生范围内，针对一种无性繁殖的植物——无花果（Ficus carica），在尽可能远离所谓的驯化中心的地方，调查了这个问题。
无花果品种在当地数量众多。它们主要是高度本地化的，对应于无性繁殖的克隆体。然而，这些克隆体通常足够古老，可以积累选择性状（无花果果皮颜色）和中性基因座（微卫星标记）的体细胞突变。此外，空间遗传结构模式与自然种群中平衡状态下的突变/漂移/迁移模型所预期的模式相似，摩洛哥传统农业生态系统中存在着均匀的本地遗传多样性水平。
我们得出结论，传统的农业生态系统即使对于无性繁殖的作物物种，也是品种多样性的活跃孵化器，即使这些品种对应于通常较老的克隆体。由于只有雌性无花果被栽培，野生无花果和栽培无花果可能在这些传统农业生态系统中构成一个单一的进化单位。核心收藏，尽管有用，但它们是博物馆，因此不能发挥与传统农业生态系统相同的作用。
