Sequence-related amplified polymorphism analysis of tree peony (Paeonia suffruticosa Andrews) cultivars with different flower colours

Sequence-related amplified polymorphism (SRAP) was used to examine genetic relatedness and genetic diversity in 16 tree peony (Paeonia suffruticosa Andrews) cultivars having different flower colours. Twenty pairs of primers generated a total of 245 scorable PCR fragments among the 16 cultivars of tree peony, of which 175 bands (71.4%) were polymorphic. Genetic relationships were obtained using Nei and Li similarity coefficients. Cluster analyses of SRAP markers using the unweighted pair-group method of arithmetic averages (UPGMA) analysis, as well as Dollo and polymorphism parsimony analyses, were largely consistent. All revealed similar genetic relationships among the 16 tree peony cultivars having different flower colours. Groupings indicated that the division of cultivars was based largely on flower colour. Three main Groups were found after cluster analyses of the 16 cultivars based on SRAP markers. Cultivars with specific flower colours always grouped together. Estimates of genetic relationships and relatedness reflected the genetic diversity in flower colour in tree peony as a whole. The results also indicated that SRAP markers are informative and can provide new insights for genetic research in tree peony.