镉胁迫下不同生态型五节芒的膜脂过氧化水平及抗氧化能力比较

Physiological Metabolism and Protective Enzyme Activity of Different Ecotypes of Miscanthus floridulus Under Cd stress

[目的]揭示不同生态型五节芒(Miscanthus floridulus)在抵抗Cd胁迫机制方面的异同。[方法]以粤北大宝山矿山开采地优势植物五节芒为试验材料,比较了五节芒非矿山生态型(采自惠州市博罗县丘陵山地)和矿山生态型(采自大宝山矿区)在相同Cd处理浓度下的生理响应。[结果]Cd胁迫会导致五节芒叶片MDA的积累,非矿区生态型五节芒MDA积累的幅度要大于矿区种群。非矿区生态型五节芒叶片中SOD活性被Cd胁迫抑制,POD活性都受到Cd胁迫的诱导而比对照有所增加,但矿区生态型增加的幅度要大于非矿区生态型,矿区生态型植株2种酶的活性在最高Cd处理浓度时都显著高于非矿区生态型植株。随Cd处理浓度增大,非矿区种群五节芒叶片中PPO活性呈先增加再下降的趋势,矿区生态型植株在受到Cd胁迫后PPO活性显著增加,在最高Cd浓度处理时矿区生态型植株PPO活性要显著高于非矿区生态型。[结论]矿山型五节芒的重金属Cd耐受性要强于非矿山型。

[Objective] The aim of the experiment was to reveal the different principle of resistant Cd exposure between two ecotypes of Miscanthus floridulus.[Method] By comparing different physiological responses under the same Cd concentration treatment between the non-mining ecotype of Miscanthus floridulus（collected from hills of Huizhou Boluo） and the mining ecotype of Miscanthus floridulus（collected from the Dabaoshan mine）.[Result] The melondialodehyde（MDA） content of the non-mine ecotype were all significantly higher than control under Cd treatment,and the mine ecotype,only 10 and 80 mg/kg treatment higher than control.It was indicated that the non-mine ecotype suffered more serious damages under Cd treatment.The activity of superoxide dismutase（SOD） of both ecotypes was inhibited under Cd treatment.The activity of peroxidase（POD） all induced to increase compare to control under Cd treatment,but the increases were more in the mine ecotype than non-mine ecotype.As the increase of the Cd treated concentration,the activity of polyphenoloxidase（PPO） of the non-mine ecotype presented the trend of first increase and then decrease,and the mine ecotype PPO was more active in the highest concentration Cd treatment（160 mg/kg） than the non-mine ecotype.[Conclusion]The mining ecotype was more active in the highest concentration Cd treatment than the non-mining ecotype.