Résumé
The contribution of farmers to maintaining genetic diversity in cultivated species is well-recognized in developing countries, but is also important to recognize farmers who participate in selection and conservation activities in developed countries. Organic and low-input farmers are increasingly concerned about the lack of adapted varieties for their environmental conditions and the loss of crop diversity which may restrict the adaptive potential of agricultural species. Participatory plant breeding and on-farm selection of heterogeneous varieties is one strategy to address this issue by bringing together the skills and knowledge of organic farmers and scientists. Two research projects on farmer selection are discussed in this paper, one in the context of a European project on the adaptation and evolution of farmer varieties, and one in the context of a farmer seed exchange network in France in which participants have been developing new populations of bread wheat from crosses between landraces and historic varieties. Preliminary results show that farmers bring a holistic approach to plant selection and that the plants they select also differ in terms of quantitative traits measured by researchers. This type of selection produced quantitative changes in the early generations of plant populations derived from crosses. The project results are also more qualitative in nature, with researchers and farmers coming to a greater understanding and appreciation of the approaches each bring to selection and conservation in the context of organic and low-input agriculture.