Assessment of genetic relation for Aegilops and Triticum possessing different genome-bearing species using start codon targeted marker

The Fertile Crescent of Southwest Asia holds high genetic diversity of crop species of tribe Triticeae, which provide staple food for the majority human population. Understanding the genetic diversity of wheat wild relatives, a valuable source of useful genes, could facilitate the introgression of useful alleles into wheat cultivars. Genetic diversity and their relationships were studied, for the first time, among 51 accessions of Aegilops and Triticum from Iraqi Kurdistan. Eighteen start codon targeted (SCoT) markers were able to generate 139 alleles. The discrimination power of the markers was assessed with polymorphism information content (PIC) and marker index (MI), that valued at 0.56 and 3.7, respectively. These results indicate the informativeness of the markers used for studying genetic diversity among the Aegilops and Triticum species, and three distinct groups were separated based on the SCoT data. All the accessions from different species with 'A' genome were clustered together in a group, including Aegilops tauschii (possessing D genome), while the Aegilops of U genome were clustered away from this group. Analysis of molecular variance (AMOVA) partitioned 62% of the variability among populations, while 38% of the variations were considered between accessions within populations. Principal coordinate analysis (PCoA) for SCoT data showed that the first two components clarified 54.73% of the total variations, indicating consistent patterns of genetic relationships between the accessions. Genetic relationships inferred from the UPGMA dendrogram were matched with the PCoA, and the grouping pattern of the accessions corresponded to their botanical classifications. The results obtained could allow for future insight into wheat breeding programs.

Automated summary

The Fertile Crescent of Southwest Asia has high genetic diversity of crop species that provide staple food for humans. The genetic diversity of wheat wild relatives was studied among accessions from Iraqi Kurdistan. Eighteen SCoT markers were used to assess genetic relationships, showing three distinct groups. The results provide insight for future wheat breeding programs.