Genetic authentication of cultivars with flower-variant types using SSR markers in spring orchid, Cymbidium goeringii

Spring orchid, Cymbidium goeringii , is one of the most important and popular species in the orchid family in Northeast Asia. The purpose of this study was to determine how closely the simple sequence repeat (SSR) genotypes match between individual plants assumed to be the same cultivar in C. goeringii . For this study, we collected 1566 samples from 17 C. goeringii cultivars of the flower-variant types and determined the frequencies and distribution of the combined genotypes of 13 SSR loci by the multiplex PCR method. The phylogenetic distance matrix and the principal coordinate analysis revealed that the correlation between horticultural phenotypes and genetic distance was loosely matched, but two cultivars of Japanese origin were clearly separated from the Korean cultivars. The results showed that the ratio of the most frequent combined genotypes in 10 cultivar groups is approximately 60%, which suggests that almost 40% of C. goeringii sold may not be genuine. This is the first forensic attempt to authenticate whether each plant is genetically genuine for the corresponding cultivars in spring orchid. We suggest preparation of a guideline for DNA deposit and profiling of the SSR genotypes for the newly registered C. goeringii cultivars and believe that this study will be helpful for establishing a molecular genetic method for forensic authentication of these cultivars.