Genetic structure of Oryza glumaepatula wild rice populations and evidence of introgression from O. sativa in Costa Rica

Abstract

Wild crop relatives are an important source of genetic diversity for crop improvement.However, gene flow from cultivated species into wild species may prove detrimental.Introgression may lead to changes in wild species by incorporating alleles from domesticated species, which may increase the likelihood of extinction. The objective of the present study is to analyze how genetic diversity is distributed within and among populations of the wild rice species Oryza glumaepatula in Costa Rica. We also evaluated if there is evidence of introgression between wild rice and commercial varieties of O. sativa since it is cultivated commonly in close proximity to wild rice populations. Individuals from all known O. glumaepatula populations in Costa Rica were collected. With the aid of 455 AFLP markers, we characterized the genetic diversity and structure among seven populations in northern Costa Rica. Given the dominant nature of our markers, Bayesian estimates of genetic structure were used. We also compared genetic diversity estimates 28Individuals from all known O. glumaepatula populations in Costa Rica were collected. 29With the aid of 444 AFLP markers, we characterized the genetic diversity and structure 30 among seven populations in northern Costa Rica. Given the dominant nature of our 31 markers, Bayesian estimates of genetic structure were used. We also compared genetic