Evaluation of Diversity Based on Morphological Variabilities and ISSR Molecular Markers in Iranian Cynodon dactylon (L.) Pers. Accessions to Select and Introduce Cold-Tolerant Genotypes.

The main goals of the present study were to screen Iranian common bermudagrasses to find cold-tolerant accessions and evaluate their genetic and morphological variabilities. In this study, 49 accessions were collected from 18 provinces of Iran. One foreign cultivar of common bermudagrass was used as control. Morphological variation was evaluated based on 14 morphological traits to give information about taxonomic position of Iranian common bermudagrass. Data from morphological traits were evaluated to categorize all accessions as either cold sensitive or tolerant using hierarchical clustering with Ward's method in SPSS software. Inter-Simple Sequence Repeat (ISSR) primers were employed to evaluate genetic variability of accessions. The results of our taxonomic investigation support the existence of two varieties of Cynodon dactylon in Iran: var. dactylon (hairless plant) and var. villosous (plant with hairs at leaf underside and/or upper side surfaces or exterior surfaces of sheath). All 15 primers amplified and gave clear and highly reproducible DNA fragments. In total, 152 fragments were produced, of which 144 (94.73%) being polymorphic. The polymorphic information content (PIC) values ranged from 0.700 to 0.928. The average PIC value obtained with 15 ISSR primers was 0.800, which shows that all primers were informative. Probability identity (PI) and discriminating power between all primers ranged from 0.029 to 0.185 and 0.815 to 0.971, respectively. Genetic data were converted into a binary data matrix. NTSYS software was used for data analysis. Clustering was done by the unweighted pair-group method with arithmetic averages and principle coordinate analysis, separated the accessions into six main clusters. According to both morphological and genetic diversity investigations of accessions, they can be clustered into three groups: cold sensitive, cold semi-tolerant, and cold tolerant. The most cold-tolerant accessions were: Taft, Malayear, Gorgan, Safashahr, Naein, Aligoudarz, and the foreign cultivar. This study may provide useful information for further breeding programs on common bermudagrass. Selected genotypes can be evaluated for other abiotic stresses such as drought and salinity.