Genetic Relationships among Native Species and Hybrid Cultivars of Asian Dendrobium (Orchidaceae) Using Amplified Fragment Length Polymorphism Markers

This study addresses the phylogenetic relationships among native species and hybrid cultivars of Asian Dendrobium by amplified fragment length polymorphism (AFLP). The plant materials of this study are composed of 37 accessions belonging to native species in China and 63 accessions proposed to be hybrid cultivars originating from Japan and Korea. Eight AFLP primer combinations produced a total of 1658 fragments with an average of 207 fragments per primer pair, of which 1655 bands were polymorphic. Specific AFLP markers were identified in 29 of 100 tested Dendrobium accessions. Unweighted pair group method based on arithmetic average (UPGMA) analysis was performed on Dice's similarity coefficient matrix and also average similarity of each species and cultivar. The tested 100 Asian Dendrobium accessions were grouped into seven clusters with the similarity coefficient of 0.49. A first cluster consisted of 63 hybrid cultivars, 17 species of section Dendrobium, one species of section Formosae, and one species of section Callista. A second, fourth, and seventh cluster included five, three, and two species of section Dendrobium, respectively. A third group comprised five species of section Formosae. A fifth and sixth cluster contained three and two species of section Callista, respectively. These results indicated that the genetic relationships among tested Asian Dendrobium accessions were related to their origins, morphological classification, flower color, and pedigree, to some extent.