The Studie On Improving The Qualities Of Fritillaria Thunbertgii Miq. Using Supplemental UV-B Radiation

To improve the industrialization of Fritillaria thunbertgii Miq. in shaanxi province, influences of supplementary UV-B radiation on the qualities of Fritillaria. thunnbergii Miq. plants were investigated in Xi'an area under the field condition. UV-B supplementary dose was 2.54, 4.25 and 5.31 kJ.m^-2.d^-1 respectively from 10:00 to 17:00 everyday during growing season (from Feburary to May).The results indicates that:(1) three levels of UV-B radiation intensity(2.54, 4.25 and 5.31kJ/m²)inhibited the growth of plants, the areas of leaf and plant dry matter weight, while the widith of stem increased. Meantime, F.thunnbergii Miq showed the largest biological response to the UV-B radiation of 5.31kJ/m2, while the least response was observed with treatment of 2. 54kJ/m² UV-B radiation.(2) Supplementary UV-B radiation had a little effects on growth, and a higher density of UV-B radiation lead smaller values of apaparent photosnthesis rate, transpiration rate, water use efficiency of plants in growing season. The increases of the content of UV absorbing compounds and PAL enzyme activity and the decrease of soluble protein as compared with controls should be defend measures of plant to the supplementary radiation, meanwhile those effects had guaranteed the growth of F.thunnbergii Miq in a certain degree and had increased content of alkaloid. The reason of reduction of soluble sugar content may be that resource allocated more to secondary metabolism under supplementary UV-B radiation. In a word the higher intension of UV-B radiation produce to the larger hurt to plants.(3) Dry weight and alkaloid of bulb of F.thunnbergii Miq were increased realated assumably to the rising of some enzyme activity during the secondary metabolism. The change of soluble sugar of old bulb was minished, but that of new bulb fluctuated. In our reseach the result of combined treatment about 4.25 kJ.m^-2.d^-1 was the best. In conclusion we can promote the content of alkaloid.in F.thunnbergii Miq. by supplementing proper UV-B radiation, while the dose rate shoul be sift carefully.