Study Of The Growth Characteristic And Active Constituents Of Dendrobium Officinale Under Different Cultivation Modes

To study the influence of different cultivation modes to D. Officinale’s growth, four kinds of cultivation modes (plants that epiphyted on longan trees, cultivated in sifting disks and seedbeds under longan trees, cultivated in vinyl tunnel) were set up for the experiment. Plants’growth characteristics included stem length, stem diameter and fresh weight were measured; and the content of polysaccharides in plants’root, stem and leaves, the content of amino acid, microelements and ethanol-soluble extracts in plants’stem were compared. Then combined with their finally economic benefits to make sure which cultivation mode was the best for D. Officinale. Under the best cultivation mode, the most suitable transmission rates was screened out by comparing the growth of D. Officinale. Besides that, the photosynthetic capacity of D. Officinale’s, under different cultivation modes was compared. The main experimental results showed that:1 The influence of different cultivation modes on the growth and content of polysaccharides of D. Officinale:arranged the length and fresh weight of stem from high to low:plants cultivated in sifting disks under longan trees, plants cultivated in vinyl tunnel, plants cultivated in seedbeds under longan trees and plants epiphyted on longan trees. Arrangeed the stem diameter from high to low:plants cultivated in sifting disks under longan trees, plants epiphyted on longan trees plants cultivated in vinyl tunnel and those cultivated in seedbeds under longan trees. The ratio of transplant from high to low:plants cultivated in vinyl tunnel, plants epiphyted on longan trees, plants cultivated in sifting disks under longan trees and those cultivated in seedbeds under longan trees. The content of polysaccharides from high to low was as follows:plants epiphyted on longan trees, plants cultivated in sifting disks under longan trees, plants cultivated in vinyl tunnel, and those cultivated in seedbeds under longan trees. The content of polysaccharides in leaves was more than that in roots, but less than that in stem. The ratio of polysaccharides in stem and leaves ranged from 1:1.6 to 1:1.7. Besides that, polysaccharides in plants’root which epiphyted on longan trees was higher, and plants which cultivated in seedbeds under longan trees was opposite.2. The influence of different cultivation modes to the other active constituents of D. Officinale:the content of ethanol-soluble extracts and the essential amino-acid from high to low wree as follows:plants epiphyted on longan trees, plants cultivated in seedbeds under longan trees, plants cultivated in sifting disks under longan trees and plants cultivated in vinyl tunnel. The total amino acids of plants that cultivated in seedbeds under longan trees was the most, plants epiphyted on longan trees was the second. The content of K, Ga and Fe in D. Officinale which cultivated in sifting disks under longan trees was the highest. The content of Mg, Mn in plants those epiphyted on longan trees was the highest. And the content of microelements in plants which cultivated in vinyl tunnel was lower than that planted under longyan trees.3. The growth of D. Officinale which epiphytied on longan trees was closely related to the transmission rates. Their growth and their content of active constituents were the best when the transmission rate was 40%. The stem length decreased when the transmission rates reduced. Arranged the length of stem, the content of polysaccharides and ethanol-soluble extracts under different transmission rates from high to low were as follows:treatment B(transmission rates was 40%), treatment C(transmission rates was 60%), control group(transmission rates was 100%) and treatment A(transmission rates was 15%). The fresh weight of stem and the ratio of transplant from high to low were as follows:treatment B, treatment C, treatment A and control group.4. Results showed that plant leaves of which epiphyted on longan trees was the narrowest; the leaf length/width was 5.57. Plant leaves of which cultivated in vinyl tunnel was larger; the leaf length/width was 2.78. Study the photosynthetic capacity of D. Officinale’s under different cultivation modes, results showed that plants’rETR, Y(II), qP, NPQ, rETRmax, and Ik which planted under longyan trees were higher than that cultivated in vinyl tunnel. That was to say their had stronger photosynthetic and photo-protection capacity and higher light saturation point. But between three cultivation modes which planted D. Officinale under longyan trees this capacity were approximate.5. Comparison the economic benefits results showed that the cultivation which planted in vinyl tunnel was with high investment and high production and it will spend four years to cover the cost. The mode that epiphyted plants on longan trees was the best cultivation mode for D. Officinale because of it’s economic mode was low input but high returns and it will be payed back in first year. The mode which plants cultivated in sifting disks under longan trees corned second. Mode cultivating in seedbeds under longan trees was the worst.In conclusion, the growth of plants which cultivated in vinyl tunnel is normal, it between that cultivated in sifting disks with that in seedbeds under longan trees. Plants’ photosynthetic capacity which cultivated in vinyl tunnel was weaker than others. And the content of polysaccharides, ethanol-soluble extracts and the other active constituents were lower than that which planted under longyan trees though their leaves were narrow. We will spend a long time to cover our cost even though this mode was high investment with high production. The mode that cultivated under longan trees was just the opposite. Conversely, the mode which epiphyted plants on longan trees was the best cultivation mode for D. Officinale because it’s low input but high returns and it had the higher active constituents.