Effects of enhanced UV-B radiation on the growth of some crops
增强的紫外线-B辐射对几种作物和品种生长的影响

Five cucumber cultivars(Cucumis sativus L.),seven tomato cultivars (Lycopsicon esculentum Mill.),soybean［Glycin max(L.)Merr.］,bean(Phaseolus vugaris L.)and watermelo(Cucumis melo L.cv.huanghemi)were investigated on their growth responses to simulating enhanced ultraviolet-B(UV-B,280～320nm)radiation(T1=8.82kJ/m2.d，T2=12.6kJ/m2.d and CK=2.2kJ/m2.d)under greenhouse conditions.After 25 days,leaf area(LA),leaf dry weight(LDW),total dry weight (TDW),plant height(PH),special leaf weight(SLW),epicotylar length(EL),girth of cotyledonary node(GCN)were measured.The results indicated that intraspecific and interspecific difference were significant.Enhanced UV-B radiation induced changes in morphological character,the reduction of biomass,plant height and leaf areas,the increase of special leaf weight and the inhibition of epicotylar growth.and finally lead to the reduction of RI (RI<0).Of the cultivars,Jingchun 3 was the most sensitive to UV-B irradiance compared with other cucumber cultivars and ganfeng 2 more tolerant than other ones.Similarly,the most inhibition to Longfan 3 in tomato cultivars was observed and longfan 7 was more tolerant cultivar.UV-B radiation inhibited the girth of cotyledonary node of tomato cultivars.But Longfan 5 did not show significantly change statistically.It is unclear that the growth of soybean under T1 treatment significantly increased.It could be infered from the results that intraspecific and interspecific difference were due to different morphology,structure,the metabolic levels,hereditary characteristic and adaptive ability to UV-B stress.