Signatures of balancing selection are maintained at disease resistance loci following mating system evolution and a population bottleneck in the genus Capsella

摘要

BackgroundPopulation bottlenecks can lead to a loss of variation at disease resistance loci, which could have important consequences for the ability of populations to adapt to pathogen pressure. Alternatively, current or past balancing selection could maintain high diversity, creating a strong heterogeneity in the retention of polymorphism across the genome of bottlenecked populations. We sequenced part of the LRR region of 9 NBS-LRR disease resistance genes in the outcrossing Capsella grandiflora and the recently derived, bottlenecked selfing species Capsella rubella, and compared levels and patterns of nucleotide diversity and divergence with genome-wide reference loci.