三种UV-B辐射强度下香蒲的生长和抗氧化状况

为了探究3种UV-B辐射强度对香蒲(Typha orientalis)生长和抗氧化状况的作用,于2017年5月19日~7月17日,在甘肃农业大学室外实验基地,构建模拟垂直潜流人工湿地,在其中栽种香蒲幼苗;在3种UV-B辐射强度168μw/cm(自然光照下)、210μw/cm和252μw/cm]下,测定香蒲的生长和抗氧化指标。研究结果表明,随着UV-B辐射增强,香蒲叶片提前出现叶缘褪绿、萎蔫和坏死斑点等现象;在短时间3种强度的UV-B辐射下,香蒲的株高和生物量都显著增大,但是随着辐射时间的增加,香蒲的生长受到抑制,且生物量表现出向地下积累的规律;在实验前14 d,随着UV-B辐射强度的增强,香蒲叶片的丙二醛、抗坏血酸和还原型谷胱甘肽含量以及超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶活性都显著提高,14 d以后,其逐渐降低;在实验的不同时期,在植物生长中起主要作用的抗氧化酶和抗氧化物质存在差异。在UV-B辐射下,香蒲通过提高其抗氧化酶活性和抗氧化物质的含量,来抵抗UV-B辐射对其造成的损伤。

Growth and Antioxidant Status of Typha orientalis under 3 Kinds of UV-B Radiation Intensities

In order to explore the effect on growth and antioxidant status of Typha orientalis under different UV-B radiation intensities, nine vertical subsurface flow constructed wetlands planted Typha orientalis were set up in the outdoor experimental base of Gansu Agricultural University from May 19 to July 17, 2017. Three kinds of UV-B radiation intensities(168 μw/cm, 210 μw/cm and 252 μw/cm) were simulated. Growth and antioxidant indexes of Typha orientalis were determined. The results showed that with the increase of UV-B radiation intensity, the time of Typha orientalis leaf edge chlorosis, wilting, and necrotic spots occur earlier gradually. Under short-term of UV-B radiation, the height and biomass of Typha orientalis increased significantly, but with the extension of radiation time, the inhibition effect appeared and biomass distribution tended to shift to underground part. In the early 14 days of the experiment, with the increase of UV-B radiation intensity, the contents of malondialdehyde, ascorbic acid and glutathione of Typha orientalis leaves were increased significantly, and the activities of superoxide dismutase, catalase, ascorbate peroxidase and glutathionereductase were enhanced. After 14 days, these indexes were reduced. The antioxidant enzymes and antioxidant substances which played a leading role in different periods of radiation were different. Typha orientalis increased its antioxidant enzyme activity and antioxidant content to resist the damage caused by UV-B radiation.