| 摘要: |
| 【目的】探讨添加外源水杨酸对镉锌胁迫下烟草幼苗生长发育及烟叶抗氧化特性的影响，为烤烟生产中减轻重金属胁迫提供理论依据。【方法】以红花大金元为供试品种，采用水培试验方法，研究高浓度(100 μmol/L)镉、锌胁迫及添加外源水杨酸（100~300 μmol/L）对烤烟幼苗生长、叶绿体光合色素、抗氧化酶活性的影响。【结果】100 μmol/L镉、锌单因子及其复合作用对烟草幼苗具有毒性效应，能显著降低烟苗生物量和光合色素的积累；且其毒性效应随处理时间延长而增强。单因子锌胁迫对烟苗的生理抑制作用强于单因子镉；镉锌复合处理具有明显的协同效应，使烟苗的生物量下降，丙二醛含量增加，SOD、POD和PPO活性降低，加重对烟苗的伤害。与正常营养液处理（CK）下的烟苗相比，处理15 d时，镉、锌单因子及其复合作用下烟叶SOD活性分别显著提高80.78%，31.79%，24.86%，POD活性分别显著提高82.74%，69.88%，64.39%，PPO活性分别显著提高 60.27%，41.50%，29.94%。添加外源水杨酸能提高镉、锌胁迫下烤烟幼苗的抗氧化酶活性，促进其生物量、光合色素和脯氨酸的积累，降低丙二醛含量；处理15 d时，添加200 μmol/L SA烟叶MDA含量比CK分别显著降低38.82%，27.18%，33.29%。【结论】本试验条件下，添加100~200 μmol/L外源水杨酸缓解镉、锌及其交互胁迫对烟草幼苗的毒害效果较好，300 μmol/L水杨酸则会抑制烟苗的生长和抗氧化酶活性。 |
| 关键词: 烤烟栽培 水杨酸 镉胁迫 锌胁迫 毒性效应 |
| DOI： |
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| 基金项目:云南省科技计划农业联合面上项目（2017FG001-063）；云南农业大学烟草学院青年扶持基金项目（2017-2）；云南农业大学大学生科技创新创业行动基金项目（2018ZKY160） |
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| Effects of exogenous salicylic acid on growth and antioxidant characteristics of flue-cured tobacco under cadmium and zinc stress |
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ZHAO Mingxiang,ZHU Yongli,XIANG Rongrong,et al
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| Abstract: |
| 【Objective】To provide basis for formulating measures to mitigate heavy metal stress in flue-cured tobacco production,the effects of exogenous salicylic acid on growth and development of flue-cured tobacco seedlings under cadmium and zinc stress were investigated.【Method】‘Honghuadajinyuan’ was selected for solution culturing and the effects of cadmium and zinc stress (100 μmol/L) and exogenous salicylic acid (100-300 μmol/L) on growth,photosynthetic pigments and antioxidant properties of tobacco seedlings were studied.【Result】Cadmium and zinc at 100 μmol/L as well as their combination had toxic effects on tobacco seedlings,and significantly reduced biomass and chloroplast pigment accumulation of tobacco seedlings.The toxic effects increased with the increase of stress time.The physiological inhibition effect of zinc stress on tobacco seedlings was stronger than that of cadmium.The cadmium and zinc combined treatment showed strong synergistic effect.It induced heavy damage to tobacco seedlings,decreased biomass,increased malondialdehyde content and inhibited activities of SOD,POD and PPO.Compared with the tobacco seedlings treated with normal nutrient solution (CK),SOD activity was increased significantly by 80.78%,31.79% and 24.86% after 15 d under cadmium stress,zinc stress and their combination,POD activity was increased significantly by 82.74%,69.88% and 64.39%,and PPO activity was increased significantly by 60.27%,41.50% and 29.94%,respectively.Adding exogenous salicylic acid increased the activities of antioxidant enzymes, promoted the accumulation of biomass,photosynthetic pigments and proline,and decreased malondialdehyde content in tobacco seedlings under cadmium and zinc stress.Compared with CK,15 d treatment decreased MDA contents by 38.82%,27.18% and 33.29%,respectively.【Conclusion】Under the experimental conditions,the toxic effect of cadmium,zinc and their interaction on tobacco seedlings was alleviated by adding 100-200 μmol/L exogenous salicylic acid,while 300 μmol/L exogenous salicylic acid inhibited the growth and antioxidant enzyme activities of tobacco seedlings. |
| Key words: flue-cured tobacco cultivation salicylic acid cadmium stress zinc stress toxic effects |
