纳米硒对棉花的促生与抗病作用

Effect of Nano Selenium on the Growth Promotion and Disease Resistance of Cotton

摘要: 为了研究纳米硒在植物保护中的作用；本研究利用一株植物内生菌合成纳米硒，并将其用于棉花抗病黄萎病的研究。体外抑菌实验表明，纳米硒对大丽轮枝菌的生长有抑制作用。促生实验表明，亚硒酸钠浓度达到50 mg/L时，植株叶片明显枯萎发黄，根长、茎长、鲜重和干重相较对照组显著降低(p < 0.05)；但随着纳米硒浓度的升高，棉花的生长变得旺盛；50 mg/L纳米硒处理组的根长、茎长、鲜重和干重显著增加(p < 0.05)。接种大丽轮枝菌后，随着纳米硒浓度的升高，植株体内叶绿素含量升高，而脯氨酸含量降低。抗氧化结果表明，随着SeNPs浓度的升高，患病棉花的抗氧化酶活性逐渐增大；相比对照组，50 mg/L SeNPs处理组叶片中的CAT、GSH、SOD显著提高；而H₂O₂、MDA、POD的活性随着SeNPs浓度的升高显著降低；这说明棉花在经过SeNPs处理后，受病原菌胁迫程度减弱。因此，SeNPs可以提高植物体内的抗氧化酶活性，从而提高植株对大丽轮枝菌的抗病性。

Abstract: To investigate the role of nano selenium in plant protection, this study utilized a plant endophytic bacterium to synthesize nano sized selenium (SeNPs) and applied it to the study of cotton resistance to Verticillium wilt. In vitro antibacterial experiments have shown that SeNPs have an inhibitory effect on the growth of Verticillium dahlia (V. dahlia). Plant growth promotion experiments have shown that sodium selenite can inhibit the growth and development of cotton. But when the concentration reached 50 mg/L, the leaves of the plant significantly wither and turn yellow. The root length, stem length, fresh weight, and dry weight of the plant were significantly reduced compared to the control group (p < 0.05). As the concentration of SeNPs continues to increase, the growth of cotton becomes vigorous. Compared with the control group and the 50 mg/L sodium selenite treatment group, the root length, stem length, fresh weight, and dry weight of the 50 mg/L SeNPs treatment group were significantly increased (p < 0.05). The antioxidant results indicate that as the concentration of SeNPs increases, the antioxidant enzyme activity of diseased cotton gradually increases. Compared with the control group, the 50 mg/L SeNPs treatment group significantly increased CAT, GSH, and SOD in the leaves. On the contrary, the activities of H₂O₂, MDA, and POD significantly decreased with the increase of SeNPs concentration, which indicates that after treatment with SeNPs, the degree of stress on cotton by pathogenic bacteria decreases. Therefore, SeNPs can enhance the activity of antioxidant enzymes in plants, thereby enhancing their resistance to V. dahlia.