补骨脂种子提取物对赤星病菌生长及其侵染烟草后抗氧化酶活性的影响

为探究补骨脂种子提取物对烟草赤星病菌的作用效果及其对烟草抗氧化酶活性的影响,以烟草赤星病病原菌链格孢菌 (Alternaria alternata) 和烤烟品种云烟87为试验材料,测定了不同浓度补骨脂种子提取物处理下赤星病菌菌丝生长情况,以及补骨脂种子提取物处理后接种链格孢菌的成熟期烟叶中防御酶活性变化。结果表明,12.5g/L 0.2%补骨脂种子提取物对赤星病菌菌丝生长的抑制效果最好,抑制率达到74%以上,且具有浓度效应和时效性。2.5g/L 0.2%补骨脂种子提取物能诱导提高烟草抗氧化酶活性,补骨脂种子提取物处理24h后接种链格孢菌,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性最高可比对照增加62.06%、93.91%和91.01 %。本论文发现补骨脂种子提取物既可抑制赤星病菌生长,又能提高烟株抗氧化能力和抗病性,有助于抵御病原物入侵,可为进一步研究补骨脂种子提取物提高植物抗病性的作用及其在防治烟草赤星病方面的应用提供一定的理论参考。

Effects of Psoralea corylifolia Linn. seed extract on the growth of Alternaria alternata and the activity of antioxidant enzymes in tobacco after infection

To investigate the effects of Psoralea corylifolia seed extract on Alternaria alternata, the pathogenic fungus causing tobacco brown spot disease, and its impact on tobacco antioxidative enzyme activity, we measured the growth of A. alternata mycelium under different concentrations of P. corylifolia seed extract treatment. We also conducted experiments using flue-cured tobacco variety Yunyan 87 and investigated the changes in defense enzyme activity in mature tobacco leaves after treatment with P. corylifolia seed extract followed by inoculation with A. alternata. The results showed that the inhibitory effect on the growth of A. alternata mycelium was most pronounced with a concentration of 12.5g/L 0.2% P. corylifolia seed extract, achieving an inhibition rate of over 74%. Moreover, this inhibitory effect exhibited concentration and time-dependent characteristics. Treatment with 2.5g/L 0.2% P. corylifolia seed extract induced an increase in antioxidative enzyme activity in tobacco plants. After 24 hours of treatment with P. corylifolia seed extract followed by inoculation with A. alternata, the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were significantly increased by 62.06%, 93.91%, and 91.01%, respectively, compared to the control. This study revealed that P. corylifolia seed extract not only inhibited the growth of A. alternata but also enhanced the antioxidative capacity and disease resistance of tobacco plants, thereby assisting in defense against pathogen invasion. These findings provide theoretical references for further research on the role of P. corylifolia seed extract in enhancing plant disease resistance and its application in the prevention and control of tobacco brown spot disease.