Genetic diversity revealed by genomic-SSR and EST-SSR markers among common wheat, spelt and compactum

In this study, two SSR molecular markers, named genomic-SSR and EST-SSR, are used to measure the genetic diversity among three hexaploid wheat populations, which include 28 common wheat (Triticum aestivum L.), 13 spelt ( Triticum spella L.), and 11 compactum (Triticum compactum Host.). The results show that common wheat has the highest genetic polymorphism, followed by spelt and then compacturn. The mean genetic distance between the populations is higher than that within a population, and similar tendency is detected for individual genomes A, B and D. Therefore, spelt and compacturn can be used as potential germplasms for wheat breeding, especially for enriching the genetic variation in genome D. As compared with spelt, the genetic diversity between common wheat and compacturn is much smaller, indicating a closer consanguine relationship between these two species. Although the polymorphism revealed by EST-SSR is lower than that by genomic-SSR, it can effectively differentiate diverse genotypes as well. Together with our present results, it is concluded that EST-SSR marker is an ideal marker for assessing the genetic diversity in wheat. Meanwhile, the origin and evolution of hexaploid wheat is also analyzed and discussed.