Morphological and genetic variation of thirty Iranian Dendranthema (Dendranthema grandiflorum) cultivars using multivariate analysis

Analysis of genetic diversity in dendranthema is necessary to improve this important ornamental species. In this study, 30 Dendranthema grandiflora cultivars were assessed based on 21 phenotypic traits and 13 ISSR loci based on a completely randomized block design with three replications in Iran. Phenotypic traits such as plant height, lateral branch number, leaf number, leaf area, and flower number had high (i.e., > 45%) phenotypic and genotypic coefficients of variation, indicating the potential of these traits for improving through targeted selection in breeding programs. All of the ISSR markers were polymorphic, and 86 alleles were identified across the cultivars. The average polymorphic information content was 0.35 with a Shannon’s information index of 0.29, indicating high levels of genetic variation in the tested cultivars. The cluster analysis based on Jaccard similarity indices (J) grouped 30 genotypes into 10 major clusters. The closest relation was observed between the ‘Oran’ and ‘Taban3′ cultivars (with 91% similarity), while ‘Fariborz’ and ‘Farahnaz’ cultivars were far apart from others (with 38% similarity). All cultivars were clearly differentiated by their ISSR fingerprints. T(GA)9 and (AGC)5GA markers had the highest molecular indices, which could be used for future breeding programs of dendranthema. Eleven cultivars were classified separately into four groups (A–D), and the remaining 19 cultivars were placed in the other four groups (E–H). The findings of this study will aid in parental selection studies for hybridization programs of dendranthema in future.