The Effects of Different Treatments with UV-B Radiation Stress on Seedling Growth and Character of Chlorophyll Fluorescence of Vicia faba L

Broad bean(Vicia faba L.)seedlings were grown under artifical enhanced UV-B radiation stress,which was used to research the responses of the growth and character of chlorophyll fluorescence of them.The results showed that enhanced UV-B radiation would shorten the seedling height by more 50%,and minish the leaf areas,and reduce the dry matter accumulation by 23.3%～61.49%,meanwhile the soluble sugar and soluble protein contents decreased evidently.The contents of Chlorophyll reduced,and the change extend of chlorophyll a was larger than chlorophyll b.Under the UV-B radiation of 0.25 W/m2,the chorophyll fluorescence of Fv/Fm,Fv/F0,φPSⅡ,qP declined obviously.When UV-B was enhanced,the chlorophyll content of seedling were declined firstly,the contents of Rubisco decreased;then the reaction center of PSII was decreased,finally which led to the photosynthesis weakened,and the synthetical and unused dry material decreased.The restrain effect under the intensity of 0.25 W/m2 UV-B is obviously;the shortening of seedling and the minish of leaf area are manners to adapt to UV-B for plant.