Variation Of Main Components Of Three New Hybrid Dendrobium Cultivars

Three superior families of Dendrobium officinale were analyzed for their dynamicchanges of polysaccharides, alcohol-soluble extracts, mineral elements and amino acids in thispaper.The results are showed as follows:1. Among D. officinale collected in different periods, both the content and amount ofpolysaccharides, alcohol-soluble extracts exist significant differences, and the content of themclosely relates to the phenology. The content of polysaccharides and alcohol-soluble extractsincreases through the growing period from the winter to February. Then the content ofpolysaccharides continues to increase rapidly, while that of the extracts decreases. The variation ofpolysaccharides is closely related to flowering. It increases rapidly at pre-bloom, and decreasessharply after flowering. Before the prolification the content reaches the highest level, and thendecreases sharply after germination. The amount of polysaccharides and alcohol-soluble extracts ishighest from early January to late July. The variation of polysaccharides among different familiesare inconsistent, while the extracts are basically identical. According to the change rules, it is morescientific to harvest the D. officinale at biennials pre-bloom than to rule the specific harvestingtime if we take the polysaccharides as a target; when we take the extracts as a target it is better toharvest before the prolification; when take the amount of polysaccharides and alcohol-solubleextracts as target, it is better to harvest from when the growing stops to the next year pre-bloom.2. The mineral elements content generally varies among different families, but in this studyonly the content of Hg and Zn shows obvious differences. We think that variety breeding perhaps agood way to control the content of mineral elements. The content of As, Cu, Cd, Mg, Ca, K, Na,B, Mn, Sr and Al of those harvested in May is lower than those harvested in February; but thecontent of Se and Pb is higher than February; and the changes of Hg, Ni, Cr and Ti are notobvious.3.The content of essential amino acids is significantly different among different families. The9×66family is much higher than others, and the differences of the basic amino acids are noapparent. Thr, Ile, Leu and Phe show the greatest differences among different families; Val, Asp,Glu, Gly, Ala, His, Arg and Pro also show obvious differences; but Met, Lys, Ser, Cys and Tyrshow no significant differences. There are big differences of the essential amino acids content among different harvesting time. Most amino acids content of the Dendrobium officinale harvestedin May are higher than those harvested in February, especially the Met, which is barely detectablein February, while increases obviously in May.