The Differences and Genetic Relationships of 4 Dendrobium Species Based on High Throughput GBS-SNP Markers

The differences and genetic relationships of 4 Dendrobium species ( Dendrobium huoshanense, Dendrobium officinale, Dendrobium moniliforme, Dendrobium Fanjingshanense ) were analyzed based on high throughput SNP markers obtained by GBS, using Dendrobium catenatum as the reference genome, for providing reference for the study of these 4 Dendrobium species. The results showed that the number of clean reads per each sample in D. huoshanense , D . officinale , D . moniliforme , D . Fanjingshanense were 1 300 724, 1 286 162, 1 380 009 and 1 170 337, respectively, and the number of SNPs per each sample were 1 507 746, 893 333, 1 364 605 and 1 227 006, respectively. The genetic structure based on Admixture software revealed that the samples of D . officinale were clustered into one branch, and the remaining Dendrobium samples were clustered into the other branch, when the best K value was 2; when k = 3, the samples of D . officinale were grouped into one cluster, some samples of D . huoshanense , all samples of D . moniliforme and D. fanjingshanense were grouped into the second cluster, and some samples of D . huoshanense were grouped into the third cluster; When k = 4, it was divided into four branches: the samples of D . officinale were grouped one branch, the samples of D . moniliforme and D . fanjingshanense were grouped one branch, the samples of D . huoshanense were divided into two branches, which was similar to the result of an unrooted neighbor-joining phylogenetic tree (NJ tree); Furthermore, principal coordinates analyses (PCoA) revealed that 91 Dendrobium samples were classed into three cluster. All samples of D. of ficinale and D. hu oshanense were grouped together, respectively, and the samples of D. monil iforme and D . fanjingshan ense were grouped together. According to the results of this study, the genetic relation of D. off icinale and the other 3 species of Dendrobium are relatively distant, and the genetic relationship of D. mo niliforme and D. fanjingshanense were relatively close, 72 samples of D . huoshanense in the study were divided into two branches, the genetic relationship in one of which was relatively close to D . moniliforme and D . fanjingshanense . The study verified that the genetic relationship between different Dendrobium species or different species of plants was investigated using SNPs detected by GBS.