Plant breeding for organic and sustainable, low-input agriculture

Participatory varietal selection: a strategy to better manage GxE interactions?
D. Desclaux, J.M. Nolot, Y. Chiffoleau, Bui Van Minh
INRA - UMR Diversité et Adaptation des Plantes Cultivées
Domaine de Melgueil, Mauguio, France
Participatory varietal selection (PVS) projects have appeared relatively recently in Northern
countries especially in organic contexts. The hypothesis underlying PVS projects can be resumed
in (i) varietal specifications vary according to the considered area (ii) the interaction (G x E) is
higher than the main effects (G or E) and therefore justify a direct evaluation i.e on target
environment, (iii) this interaction is mainly caused by local conditions (soil, practices) that can
not or costly be simulate in research stations, (iv) the term E must include not only agroecological
but also socio-economic conditions.
Based on an experimental decentralized PVS program aiming to create durum wheat varieties
adapted to organic conditions in the south of France, these hypotheses are discussed. All of them
are not confirmed by the results of the program but structuring environments according to
agronomical, sociological and economical diagnosis helps to improve the choice of the right
genotypes and lead to a better mastering of breeding targets. This project also emphasizes the
benefits to be obtained from open interactions between different professional partners and
researchers from relevant disciplines. Multi-level interactions and cross-linked learning
processes about breeding methods are needed for effective communication between different
stakeholders and scientific disciplines. Varietal selection or co-evaluating is no longer only an
end in itself but also a means of facilitating the production of knowledge and rules relevant for
the development of sustainable development of specific agro-food system.
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