Studies On Effect Of Light Quality And Photosynthetic Characteristics Of Dendrobium Officinale

The Dendrobium officinale is the leader of the top nine medicinal herbs in our country, which hasthe special efficacy of reinforcing stomach reg fluid and nourishing yin clearing heat.It always used inthe treatment of chronic atrophic gastritis, hypertension, diabetes mellitus, tumours and so on.It alsohas the function of anti-aging. Based on the test-tube plantlet and different germplasm ofD.officinale,the effect of light quality and photosynthetic characteristics were studied which aimed tolaid a foundation for the high quality, low carbon and efficient production of D.officinale, and givesuseful tips on production of high quality ingredients. The main achievements of our studies are asfollowing:Effects of light quality and germplasm on the growth and effective ingredients ofDendrobium officinale germchit were studied.Under8light qualities(red, blue, yellow,green,write and three different red blue mix light)，test-tube plantlets of different families(9×66、17×30、78×68)were used in the experiments to measure economical characters and determine the contents ofchlorophyll, polysaccharides,total alkaloids and enzyme activities. The results showed that light quality,germplasm and their interaction have a significant effect on the growth of D.officinale germchit. Greatestroot length and the highest height of seedling were obtained under red light, under blue light, the stemdiameter was thickest and the contents of total alkaloids were highest, the contents ofchlorophyll,polysaccharides and enzymatic activity of test-tube plantlets under red blue mix light （8:2）were higher than other treatments. This work has laid a foundation for the high quality, lowcarbon and efficient production of D.officinale, and gives useful tips on production of highquality ingredients.The photosynthetic of different germplasm of D.officinale were studied. Using “Li-6400photosynthetic determination systm”, the diurnal variation of net photosynthetic rate,the environmentfactor of photosynthetic rate, the light response curve of net photosyntheticate to PPFD weremeasuremented, The results showed that the curves of diurnal variation of net photosynthetic rate inleaves of D.officinale showed one peaks and the net photosynthetic rate,the light saturation point,thelight compensation point was very low. There were significant difference among different germplasm ofD.officinale. The Photosynthetic Characteristics of D.officinale showed the character of shade plants,Itneeds less light so we should control the light intensity to make sure the the high quality, low carbon and efficient production of D.officinale.