Recent long-distance transgene flow conforms to historical patterns of gene flow in wild cotton (Gossypium hirsutum) at its center of origin

Over 95% of the currently cultivated cotton was domesticated from Gossypium hirsutum, which originated and diversified in Mexico. Population dynamics and genetic studies of this species at its center of origin and diversification are lacking, although they are critical for cotton conservation and breeding. We investigated the actual and potential distribution of wild cotton populations, as well as the contribution of historical and recent gene flow in shaping cotton genetic diversity and structure. We evaluated historical gene flow using chloroplast microsatellites and recent gene flow through the assessment of transgene presence in wild cotton populations, exploiting the fact that genetically modified cotton has been planted in the North of Mexico since 1996. Assessment of geographic structure through Bayesian spatial analysis, BAPS and Genetic Algorithm for Rule-set Production (GARP), suggests that G. hirsutum seems to conform to a metapopulation scheme, with eight distinct metapopula...