[Comparative analysis of agronomic and qualitative characters in different lines of Dendrobium denneanum]

To provide theoretical basis for breeding good variety of Dendrobium denneanum, agronomic and qualitative characters of 4 different lines and relationships among them were studied. The stem length, stem diameter, leaf length, leaf width, length/ width ratio and leaf area were measured. The single fresh and dry stem was weighed and drying rate was calculated. The contents of polysaccharides and total alkaloids were determined by sulfuric acid-phenol colorimetry and acid-dye colorimetry, respectively. The correlations between characters were analyzed. The results showed that differences in major agronomic characters between four lines were significant. The plant types of dq-1 and dq-2 were higher, dq-3 was medium and dq-4 was lower. The fresh weigh of stem and content of polysaccharides were the highest in dq-2, 7.81 g and 14.33%. While the highest content of total alkaloids and was 0. 486% in dq-3. There were significant correlations between agronomic characters, but these characters had low or non correlations with qualitative characters such as polysaccharides and total alkaloids. It was shown that the content of polysaccharides and total alkaloids were significantly different among 4 lines of D. denneanum, which could be selected for different uses.