锌胁迫对国槐幼苗生长及生理特性的影响

为探讨国槐(Sophora japonica)对重金属锌的耐受能力,以水培的3月龄国槐幼苗为试验对象,探讨不同浓度(1、50、200、350、500 μmol/L)锌处理对其生长发育、叶绿素荧光参数、丙二醛含量和抗氧化酶活性的影响.结果 表明,在锌胁迫下,国槐幼苗生长量指标呈现明显的"低促高抑"现象,同时,根系对锌胁迫...

Effects of Zinc Stress on the Growth and Physiological Characteristics of Sophora japonica Seedlings

To explore the tolerance of Sophora japonica to heavy metal zinc, this study used three-month-old seedlings of S. japonica from hydroponics as experimental objects, to explore the effects of different concentrations (1, 50, 200, 350, 500 μmol/L) of zinc on the seedling growth and development, chlorophyll fluorescence parameters, malondialdehyde content and antioxidant enzyme activity. The results showed that under zinc stress, the growth index of S. japonica seedlings presented an obvious phenomenon of ‘low promotion and high inhibition’. At the same time, the roots of S. japonica seedlings were more sensitive to zinc stress. The chlorophyll fluorescence parameters changed significantly with different concentrations of zinc. Both F₀ and Φ_NPQ decreased first and then increased with the increase of zinc concentration, while F_v/F_m, Φ_PSII and SPAD values showed opposite trends. At 7, 14, 21, and 28 days after zinc stress, the content of MDA decreased first and then increased with the increase of treatment concentration, and increased with the increase of stress time, the activity of antioxidant enzymes increased first and then decreased with the increase of zinc treatment concentration. When the stress time prolonged, the activities of SOD and CAT decreased gradually, POD activity reached its peak after 21 days of treatment and began to decline. This study signifies that S. japonica seedlings have a certain tolerance to zinc stress environment, the seedlings have strong adaptability under a zinc concentration of not higher than 200 μmol/L, but would be poisoned by zinc when the concentration is higher than 200 μmol/L.