Genetic diversity, population structure and identification of Dendrobium cultivars with high polysaccharide contents using SCoT, SCAR and nested PCR markers

Abstract

Dendrobium officinale Kimura et Migo (D. officinale) is not only an ornamental plant with beautiful flowers but also a medicinal herb that is widely used in traditional Chinese medicine. We used start codon targeted (SCoT) polymorphism molecular markers to analyse eleven Dendrobium cultivars. Using 13 selected SCoT primers, 181 bands were generated, 157 (86.86%) of which were polymorphic. The eleven cultivars were clustered into two major groups based on a SCoT analysis by the unweighted pair-group method with arithmetic mean. Then, we developed SCoT-sequence-characterised amplified region (SCoT-SCAR) markers and SCoT-nested polymerase chain reactions as the complementary tools for the identification of high-polysaccharide-content D. officinale cultivars. A D. officinale ‘Ruishen No.2’-specific band was detected in the PCR products. The primers, which were designed to target a specific band, amplified the target bands in D. officinale ‘Ruishen No.2’, but not in the ten other cultivars. The universal verification test showed that there were not any target bands being amplified with the primer SC1, SC2, and SC3 to the seventeen Dendrobium cultivars from all over the world, which more to prove the reliability of the experimental results using the SCoT-SCAR markers and the SCoT-nested PCR markers. This study provides guidelines for D. officinale ‘Ruishen No.2’ identification, for the breeding of D. officinale plants with a high content of active ingredients, and for industrial production.