燕麦植株生长及叶片生理活性对土壤镉胁迫的响应

Response of Oat Plant Growth and Leaf Physiological Activity to Soil Cadmium Stress

该研究以燕麦品种‘燕科2号’(籽粒镉积累量高,Yh)和‘200919-7-1’(籽粒镉积累量低,Yl)为材料,采用盆栽试验,在土壤Cd胁迫条件下测定两种类型燕麦植株生长、叶片光合生理参数及抗氧化酶活性的变化,探讨两品种对Cd胁迫的响应差异。结果表明:(1)Cd胁迫条件下,燕麦品种Yh和Yl植株生长、气体交换参数及叶绿素荧光参数均受到抑制,并以单株干重、叶片净光合速率(P)、光化学淬灭系数(qP)表现最为突出,Yh的降幅分别为38.2%、35.0%、14.7%,Yl降幅分别为40.8%、57.1%、27.3%。(2)镉胁迫均诱导增强了两个类型燕麦品种叶片抗氧化酶活性,尤其是SOD活性得到显著增强,Yh和Yl的增幅分别为41.9%和44.9%;Cd胁迫也显著提高了MDA含量,Yh和Yl的增幅分别达到22.2%和18.1%。研究发现,在Cd胁迫条件下,与低Cd积累燕麦品种相比,高Cd积累燕麦品种具有较高的生物量和抗氧化酶活性,以及较强的净光合速率和优异的叶绿素荧光特性,从而表现出较强的耐Cd性。

In this study, oat cultivars ‘Yanke 2’(high grain cadmium accumulation, Yh) and ‘200919-7-1’(low grain cadmium accumulation, Yl) were used as materials, and pot experiments were carried out under the condition of soil Cd stress. The changes of plant growth, leaf photosynthetic physiology and antioxidant enzyme activities of the two types of oats were measured, and the differences in the responses of the two cultivars to Cd stress were discussed. The results showed that:(1) under Cd stress, the plant growth, gas exchange parameters and chlorophyll fluorescence parameters of high Cd accumulating oat cultivar(Yh) and low Cd accumulating oat cultivar(Yl) were inhibited, and the dry weight per plant, Pand qP were the most prominent. The decrease rates of Yh and Yl were 38.2% and 40.8%, 35.0% and 57.1%, 14.7% and 27.3%, respectively.(2) Cd stress induced the activities of antioxidant enzymes in leaves of the two types of oat cultivars, especially SOD activity was significantly enhanced, Yh and Yl increased by 41.9% and 44.9%, respectively;at the same time, Cd stress significantly increased MDA content, Yh and Yl increased by 22.2% and 18.1%, respectively. The study found that under Cd stress conditions, compared with the low Cd accumulation varieties, the high Cd accumulation varieties had higher biomass and antioxidant enzyme activities, as well as stronger net photosynthetic rate and excellent chlorophyll fluorescence characteristics, showing a relatively high level of chlorophyll fluorescence and strong Cd resistance.