On‐farm dynamic management of genetic diversity: the impact of seed diffusions and seed saving practices on a population‐variety of bread wheat

• Published in: Evolutionary applications 2012-12, Vol.5 (8), p.779-795
• Main Authors: Thomas, Mathieu, Demeulenaere, Elise, Dawson, Julie C., Khan, Abdul Rehman, Galic, Nathalie, Jouanne‐Pin, Sophie, Remoue, Carine, Bonneuil, Christophe, Goldringer, Isabelle
• Format: Article
• Language: English
• Subjects: Barley; Biodiversity; Case studies; Cassava; Corn; Crop diversification; Crops; Cultural history; Diffusion; Domestication; Environment and Society; Environmental Sciences; Environmental studies; Ethnobotany; Evolution; Farmers; Gene flow; Genetic diversity; Genetic drift; Genetic structure; Genetics; Humanities and Social Sciences; in situ conservation; interdisciplinary study; Life Sciences; Microsatellites; Mitochondrial DNA; network theory; Original; Parameter estimation; Population genetics; Population structure; Populations and Evolution; seed exchange network; Sorghum; Triticum aestivum
• ISSN: 1752-4571; 1752-4563; 1752-4571
• DOI: 10.1111/j.1752-4571.2012.00257.x

Since the domestication of crop species, humans have derived specific varieties for particular uses and shaped the genetic diversity of these varieties. Here, using an interdisciplinary approach combining ethnobotany and population genetics, we document the within‐variety genetic structure of a population‐variety of bread wheat (Triticum aestivum L.) in relation to farmers’ practices to decipher their contribution to crop species evolution. Using 19 microsatellites markers, we conducted two complementary graph theory‐based methods to analyze population structure and gene flow among 19 sub‐populations of a single population‐variety [Rouge de Bordeaux (RDB)]. The ethnobotany approach allowed us to determine the RDB history including diffusion and reproduction events. We found that the complex genetic structure among the RDB sub‐populations is highly consistent with the structure of the seed diffusion and reproduction network drawn based on the ethnobotanical study. This structure highlighted the key role of the farmer‐led seed diffusion through founder effects, selection and genetic drift because of human practices. An important result is that the genetic diversity conserved on farm is complementary to that found in the genebank indicating that both systems are required for a more efficient crop diversity conservation.