Traditional agroecosystems as conservatories and incubators of cultivated plant varietal diversity: the case of fig (Ficus carica L.) in Morocco
1 INRA, UMR 1098, Développement et Amélioration des Plantes (DAP), Bat. 3, Campus CIRAD TA A 96/03, Av. Agropolis, 34398 Montpellier Cedex 5, France
2 Montpellier SupAgro, UMR 1098 DAP, Bat. 3, Campus CIRAD TA A 96/03, Av. Agropolis, 34398 Montpellier Cedex 5, France
3 Faculté des Sciences de Tétouan, Diversité et Conservation des Systèmes Biologiques, BP 2062, M'hannech II Tétouan, Maroc
4 INRA, UR Amélioration des Plantes et Conservation des Ressources Phytogénétiques, BP 578 Meknès, Maroc
5 INRA, UMR 1097, Diversité et Adaptation des Plantes Cultivées (DiA-PC), Bat. 33, 2 place Viala, 34060 Montpellier Cedex 2, France
6 CNRS, UMR 5175, Centre d'Ecologie Evolutive et Fonctionnelle (CEFE), 1919 route de Mende, 34293 Montpellier Cedex 5, France
7 Conservatoire Botanique National Méditerranéen de Porquerolles, UMR 1098 DAP, 76 A, Av. Gambetta, 83400 Hyères, France
BMC Plant Biology 2010, 10:28 doi:10.1186/1471-2229-10-28Published: 18 February 2010
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.