This article, using an institutional and political ecological perspective, analyses the role of knowledge networks supporting peasant seed groups in France. These groups promote a dynamic approach to agrobiodiversity restoration , developing new models of collaborative "peer-to-peer genetics" and distributed participatory breeding. Our analysis focuses here on the small grain cereal participatory breeding group. Based on detailed qualitative surveys and a network formalization, our study provides a better understanding of how these peasant seed groups self-organized and of how their horizontal and distributed network structure favors the dynamics of collective learning and knowledge spillovers. Further directions for policy making are discussed in support of more resilient plant breeding and agrobiodiversity restoration in European agricultural landscapes.