Genetic variability and population structure of Agropyron desertorum accessions from Iran based on ISSR assay

Abstract

Abstract The genus Agropyron as forage plant has several species which represented resistance against environmental stresses. DNA markers possessed a key role in assessment of plant germplasm and parental selection. In this regard, the genetic diversity of 34 A. desertorum accessions was studied using 28 ISSR primers. A total of 448 loci were amplified in A. desertorum genome that 402 (90%) out of them were polymorphic. The primer (AG)8YC produced the greatest number of polymorphic fragments while the primer (AC)8YA produced the lowest number. The number of effective alleles ranged between 1.26 and 1.57. The highest value of Shanon index was belonged to primer (GA)8T while the highest value of Nei index (0.33) was detected for primers (GA)8T, (TC)8C, and (GACA)4. Primer (GA)8GCC with PIC = 0.40 was the best informative marker in evaluation of A. desertorum genetic diversity. Genetic similarity among studied accessions was between 0.45 (G03 and G17) and 0.80 (G01 and G11). Using Bayesian and WPGMA classification algorithms, the A. desertorum germplasm was divided into two major subgroups (Red and Green) consisted of 13 and 17 accessions and also admixture accessions. Late mature accessions were distinguished from early mature accessions and mostly localized in Green subgroup. The Red subgroup had more private allele as well as heterozygosity compared with Green subgroup and therefore had also promising selection potential. Totally, ISSR markers could distinguished early mature genotypes and this is significant for more forage yield. Likewise, the recognized heterotic groups could help breeders to select highly polymorphic genotypes in polycross breeding.