Assessment of genetic diversity among Iranian Aegilops triuncialis accessions using ISSR, SCoT, and CBDP markers

Crop wild relatives (CWRs) are commonly used as a suitable genetic reservoir for plant breeding. They can be used for enhancing the tolerance of plant varieties to biotic and abiotic stresses. Studying the genetic diversity of related wheat species in Iran could be useful to improve different traits of bread wheat, since the country is one of the major centers of genetic diversity and distribution of Aegilops species. Therefore, the aim of the present study was to determine the relationship among 48 Aegilops triuncialis accessions using three DNA marker systems, including start codon targeted (SCoT), CAAT box-derived polymorphism (CBDP), and inter-simple sequence repeat (ISSR) markers.

A total of 359 amplified DNA fragments were generated using 13 CBDP, 14 SCoT, and 16 ISSR primers that produced 96, 147, and 152 bands, respectively. The discriminating power of the three markers was assessed using polymorphism information content (PIC), marker index (MI), and resolving power (Rp). The mean values of PIC for ISSR, SCoT, and CBDP markers were 0.3, 0.26, and 0.34, respectively, indicating the efficiency of the three markers in detecting polymorphism among the studied accessions. ISSR markers had the highest values of MI, Rp, and polymorphism percentage as compared to SCoT and CBDP markers. Based on the Shannon index and heterozygosity values, genetic diversity in the Alborz population was more than in other populations. The accessions were classified into six, five, and five groups based on ISSR, SCoT, and CBDP using the UPGMA method. According to the results of cluster and PCoA analyses, the variation patterns corresponded with the geographical distribution of the Ae. triuncialis accessions.

The three markers provided a comprehensive pattern of the genetic diversity among the Iranian Ae. triuncialis accessions. This information could allow for a future insight into wheat breeding programs.