Evaluation of the genetic diversity and population structure of reticulated iris accessions in the Iraqi Kurdistan region using SCoT and SRAP markers

The reticulated iris is one of the most attractive wild ornamentals and bulbous irises and is widely distributed throughout the mountains of the Iraqi Kurdistan region. Because little is known about the genetic diversity and population structure of this plant species in Iraq, this study was undertaken to fill that gap. In the present study, 10 start codon-targeted (SCoT) polymorphic and 10 sequence-related amplified polymorphism (SRAP) markers were used to assess the genetic diversity and population structure of 50 wild reticulated iris accessions from five different sites in Iraqi Kurdistan. Overall, the SCoT and SRAP markers produced 135 and 87 polymorphic bands, respectively. The average number of polymorphic bands (TPB), number of observed alleles (Na), Shannon’s information index (I), effective number of alleles (Ne), expected heterozygosity or gene diversity (He), polymorphic information content, and unbiased expected heterozygosity (uHe) were 13.7, 1.54, 0.35, 1.40, 0.23, 0.31, and 0.25, respectively, for the SCoT markers and 8.7, 1.54, 0.36, 1.40, 0.24, 0.32, and 0.25, respectively, for the SRAP markers. According to the unweighted pair group method with arithmetic mean (UPGMA) dendrogram and structure analysis, SCoT markers grouped 50 reticulated iris accessions into two main clades with some subclades, SRAP markers separated these accessions into four main clades, and the combination of both markers divided all accessions into five main clades. The analysis of molecular variance revealed 80.00, 76.00, and 78.38% variability within populations using SCoT, SRAP, and SCoT+SRAP markers, respectively. Except for the private band numbers for the SCoT, SRAP, and SCoT+SRAP markers, population 3, population 1, and population 3 had the highest diversity indices, respectively. The highest genetic similarity among populations was revealed by the SRAP markers between population 2 and population 3, with 92% similarity. The findings of this study demonstrate the efficacy of these markers for determining genetic variation in iris accessions, in addition to their use in conserving germplasm and genome diversity.