干旱胁迫下CO2浓度倍增对达乌里胡枝子幼苗生长及抗氧化特性的影响

为探讨CO₂浓度倍增对达乌里胡枝子(Lespedeza davurica)自然干旱胁迫的生长及抗氧化特性的影响，本试验通过人工气候培养箱控制不同CO₂浓度(400μmol·mol^-1(CK)和800μmol·mol^-1(DCO₂))，在自然干旱胁迫条件下每隔2d(共8次)测定幼苗生长特性和抗氧化特性。结果表明：CO₂倍增缓解了干旱胁迫对达乌里胡枝子幼苗株高的抑制作用，同时促进其主根的生长；CO₂倍增提高了干旱胁迫下达乌里胡枝子幼苗的超氧化物歧化酶和过氧化物酶活性，增加了叶片相对含水量和脯氨酸含量，抑制了丙二醛合成，降低了相对电导率。综上所述，CO₂倍增在一定程度上提高了达乌里胡枝子幼苗叶片的抗氧化酶活性，延缓膜脂过氧化的发生，提高达乌里胡枝子幼苗对干旱的耐受性。

Effects of Doubling CO2 Concentration on the Growth and Antioxidant Characteristics of Lespedeza davurica Seedlings Under Drought Stress

In order to investigate the effects of CO₂ doubling on growth and antioxidant properties of Lespedeza Davurica under natural drought stress,different CO₂ concentrations (400 μmol·mol^-1 (CK) and 800 μmol·mol^-1 (DCO₂)) were controlled in an artificial climate culture chamber. Seedling growth and antioxidant properties were measured every 2 d (8 times in total) under natural drought stress. The results showed:the doubling increase of CO₂ alleviated the inhibition effect of drought stress on plant height and promoted the taproot growth of Lespedeza Davurica seedlings simultaneously. The doubling increase of CO₂ promoted the activities of superoxide dismutase and peroxidase,increased the relative water content and proline content of leaves,inhibited the synthesis of malondialdehyde,and decreased the relative electrical conductivity of Lespedeza Davurica seedlings under drought stress. To a certain extent,the doubling increase of CO₂ raised the activity of antioxidant enzymes,delayed the occurrence of membrane lipid peroxidation,and improved the drought tolerance of Lespedeza Davurica seedlings.