土壤水分对胡椒实生苗生长和活性氧代谢的影响

为探讨土壤水分对胡椒生长和叶片活性氧代谢的影响，以胡椒实生苗为研究对象，设置5%、10%、15%、20%和25%共5个土壤质量含水量处理，测定试验开始后第1、3、5、8、14天不同处理的抗氧化酶活性、膜脂过氧化产物及第14天时植株相关生长指标，以期明确适宜胡椒生长的土壤含水量范围。结果表明：1～3 d内，5%土壤水分处理表现出胡椒叶片抗氧化酶活性显著高于其他处理，15%和20%处理最小，受到的胁迫程度最低；而3 d后，由于5%处理胡椒叶片失水严重，抗氧化酶活性显著降低，10%处理仍呈现较高水平；总体趋势上，15%、20%和25%处理的膜脂过氧化程度最低，生长状况也最好。上述结果表明，适宜胡椒生长的土壤质量含水量范围为15%～25%，土壤水分含量过低形成的干旱胁迫会影响胡椒生长，降低叶片抗氧化能力，加重膜脂过氧化伤害程度。

Response of Active Oxygen Metabolism of Black Pepper Seedling to Different Soil Moisture Regimes

To investigate the suitable soil moisture content for Black Pepper growth, a greenhouse experiment of Black Pepper seedlings grown in different soil mass moisture regimes of 5%, 10%, 15%, 20% and 25% was carried out and the effect of different soil moisture regimes on antioxidant enzyme activities, membrane lipid peroxidation and normal growth indexes of Black Pepper seedling was studied. The results showed that, under water stress, the activities of superoxide dismutase(SOD), catalase(CTA), and peoxidase(POD) in leaves of the 5% treatment was significantly higher than other treatments. Otherwise, 3 days later, because of the loss of water in the 5% treatments leaves, the antioxidant enzyme activity was significantly decreased. The membrane lipid peroxidation of 15%, 20% and 25% treatment is lowest, with the seedlings grew well. Soil moisture beyond the range would induce drought stress, which caused the decrease of the antioxidant enzyme activities and the rise of the membrane lipid peroxidation, inhibited the growth of pepper seedlings.