【摘要】 探明烟苗对UV-B辐射强度的响应能力,为其生产应用提供科学依据,以K326和红花大金元(以下简称"红大")为研究对象,设0μW/cm2(CK)、35μW/cm2(T1)、60μW/cm2(T2)、85μW/cm2(T3)和110μW/cm2(T4)5个辐射强度处理进行人工模拟试验,研究其对烟苗生长和抗氧化酶活性的影响。结果表明:UV-B辐射使烟苗矮化,茎围、叶面积和主根长显著减少,但低强度UV-B辐射可促使烟苗变成矮壮紧凑的株型,2个品种的变化趋势总体一致,但红大对UV-B辐射的适应性更强。过氧化物酶(POD)活性,随着UV-B辐射强度的增大,不同时期UV-B辐射处理K326和红大的POD活性均显著高于CK,各UV-B辐射处理间K326的POD活性呈先升后降趋势,各UV-B辐射处理间红大的POD活性均呈升高趋势;超氧化物歧化酶(SOD)活性,随着UV-B辐射强度的增大,在前期和中期UV-B辐射处理K326和红大的SOD活性显著高于CK,前期各UV-B辐射处理除K326的SOD活性呈升高趋势外,中后期呈先升后降趋势,前期各UV-B辐射处理除红大的SOD活性变化不大外,中后期也呈先升后降趋势;过氧化氢酶(CAT)和多酚氧化酶(PPO)活性也呈一定的规律性变化。2个品种烟苗的抗氧化酶活性对UV-B辐射的响应存在差异,且红大对UV-B辐射的耐受性强于K326。更多还原

【Abstract】 The response ability of tobacco seedlings to UV-B radiation intensity was proved to provide a scientific basis for its production and application.K326 and Hongda were used as the research objects.Five radiation intensity treatments 0μW/cm2(CK)、35μW/cm2(T1)、60μW/cm2(T2)、85μW/cm2(T3)and 110μW/cm2(T4)were used for artificial simulation tests to study their effects on the growth and antioxidant enzyme activities of tobacco seedlings.The results showed that UV-B radiation caused the tobacco seedlings to dwarf,and the stem circumference,leaf area and taproot length were significantly reduced,but the low-intensity UV-B radiation could promote the tobacco seedlings to become short,strong and compact plants,the overall trend of change of the two varieties was the same,but Hongda had a stronger adaptability to UV-B radiation.POD activity of K326 and Hongda,with the increase of UV-B radiation intensity,were significantly higher than CK in different periods.K326 showed a rising and then falling trend among the UV-B radiation treatments,while Hongda showed only increasing trend among the UV-B radiation treatments.With the increase of UV-B radiation intensity,the SOD activity of K326 and Hongda in the early and middle stages was significantly higher than that of CK,K326 showed an increasing trend in the earlier UV-B radiation treatments,but a rising and then falling trend in the later treatments.As for Hongda,in addition to the slight change of SOD activity in the early stage of UV-B radiation treatment,it also increased and then decreased in the later stage.CAT and PPO antioxidant enzyme activities also showed regular changes.The antioxidant enzyme activities of tobacco seedlings of the two varieties were different in response to UV-B radiation,and the resistance of Hongda to UV-B radiation was stronger than that of K326.更多还原