**5. Conclusions**

Weighted gene co-expression network associated with traits was constructed, and 19 tissue and species-specific modules were obtained. The biological significance of the tissue and species-specific module was revealed, the regulatory genes related to the medicinal components of *Dendrobium* were identified, and a local biologically significant network was constructed. The results of this study can provide important experimental data and theoretical basis for the further analysis of the genetic mechanism of the medicinal ingredients of *Dendrobium*.

**Supplementary Materials:** Supplementary materials can be found at http://www.mdpi.com/1422-0067/21/3/861/s1.

**Author Contributions:** Conception and design of the research: Y.Y. and X.T.; acquisition of data: B.Z.; statistical analysis: X.T.; drafting the manuscript: Y.Y. and J.Z.; revision of manuscript for important intellectual content: J.L. All authors read and approved the final manuscript.

**Funding:** This project was funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), National Foundation of Forestry Science and Technology Popularization (Grant No. [2015] 17), Major Fund for Natural Science of Jiangsu Higher Education Institutions (Grant No. 15KJA220004).

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


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*Communication*
