Abstract: In order to provide scientific basis for the identification,classification and application of dendrobium germplasm resources,the medicinal components of 6 species of dendrobium were determined and their nutritional value was evaluated.Selecting 6 species of dendrobium in Sect. Formosae as materials,the contents of polysaccharides,alcohol-soluble extracts,dendrobine and 17 kinds of amino acids were determined by sulfuric acid-phenol method and anino acid analyzer analysis,thermal leaching method,gas chromatography and acid hydrolysis method respectively.The contents of polysaccharides was between 0.59%~17.08%,alcohol-soluble extract was between 7.62%~13.54%,dendrobine was not detected in all samples;all of dendrobiums contain 17 amino acids other than tryptophan,the total amount is between 3.45% and 4.53%.Amino acid ratio coefficients (SRC) of 6 species of Dendrobium ranged from 52.42 to 83.74.The statistical description and analysis showed that the polysaccharide variation coefficient of 6 species of Dendrobium was the largest (137.24%),followed by the alcohol-soluble extracts (18.95%).The correlation analysis showed that there was some significant correlation between the nutritional components,but no significant correlation between the medicinal components and the nutritional components and the medicinal components.6 species of Dendrobium in Sect. Formosae were rich in amino acids,which could provide high quality protein.The difference of pharmacodynamic components was significant,suggesting that their pharmacological effects were different,production and application should be carried out according to the difference of composition and content.This study has guiding significance to the breeding of excellent species of Dendrobium and the exploitation of Dendrobiumresources.

Key words: Sect. Formosae, effective components, nutritional value, correlation coefficient, resource exploitation