Abstract:

To investigate the genetic diversity and relatedness of different species of Dendrobium,the genomic DNA of 48 Dendrobium leaves of different varieties was collected, and 15 SCoT primers with rich polymorphism and good repeatability were screened from 36 primers by using 2 randomly selected DNA samples, and then the collected genomic DNA of 48 Dendrobium were amplified by SCoT-PCR and the genetic diversity was analyzed. The results showed that a total of 224 clear bands were amplified from the 15 primers selected, of which 217 were polymorphic bands, and the polymorphism ratio (PPR) was 96.88%. Each primer can detect 12 to 20 allelic sites. The results of cluster analysis showed that the genetic similarity coefficient of 48 samples of Dendrobium was between 0.55 and 0.78. The tested Dendrobium can be divided into 5 groups at the level of genetic coefficient 0.659. Fifteen SCoT primers were used to effectively distinguish 48 Dendrobium materials and divide them into 5 groups. There are significant differences in the genetic background of 48 types of Dendrobium materials, providing theoretical guidance for the protection of Dendrobium resources.

Key words: Dendrobium, SCoT markers, genetic diversity