The Effection Of Synergy Between Ca, Al On Several Physiological And Biochemical Features Of Chinese-fir Seedlings

In this paper, on the status of the effection to Chinese-fir plantation productivity by Al, we tried to do hydroponic experiment of Chinese-fir seedlings by"high aluminum concentration high calcium concentration design".we study physiological and biochemical changes of Chinese-fir seedlings during different aluminum stress time(8 days, 16 days, 24 days), including MDA, SOD, CAT, POD in Chinese-fir seedling leaves and also the K content,Ca content, Mg content, Fe content in roots, stems and leaves of Chinese-fir seedling. Through the analysis of physiological and biochemical changes of Chinese-fir seedlings, we tried to study the alleviation of aluminum toxicity of it by different calcium concentration. The results were as follows:1. The effection on several physiological and biochemical features of Chinese-fir sedlings by the condition of different Calcium concentrations under high aluminum concentrationDifferent Ca concentration have significant effection on MDA content, SOD activity, CAT activity, POD activity under high Al condition.MDA content. Along with the increase of stress time, the MDA content increased significantly in all treatment; in the same stress time, along with the increase of Ca concentration, the MDA content gradually decreased in all treatment. It appears: zero Ca concentration>low Ca concentration >middle Ca concentration > high Ca concentration, and the gap among them are increased along with the stress time.SOD activity. Along with the increase of stress time, the SOD activity gradually decreased in the treatment of zero Ca concentration, low Ca concentration , middle Ca concentration. In high Ca concentration treatment, it is increased in eralier stage, but then decreased. In the same stress time, along with the increase of Ca concentration, SOD activity is significantly decreased slower, and it is first increased and then decreased in high Ca concentration.The CAT activity and POD activity showed the same trend of the SOD activity.2. The effection on nutrient absorption of Chinese-fir sedlings by the condition of different calcium concentrations under high aluminum concentrationDifferent Ca concentration had significant effection on K content, Ca content, Mg content, Fe content separately in leaves, stems and roots of Chinese-fir seedlings under high Al condition.K content. Along with the stress time, K content of leaves and roots gradually decreased. But K content changed somewhat different of stems, it increased slightly in high Ca concentration treatment, while it had the same change of leaves in other treatment. In the same stress time, along with the increase of Ca concentration, generally, the K content in zero Ca concentration treatment is the lowest, and highest in high Ca concentration treatment of leaves, stems and roots. The gap is significant in later stage(24 days). K content appears: zero Ca concentration>low Ca concentration >middle Ca concentration > high Ca concentration. Ca content. Along with the stress time, the Ca content of leaves, stems and roots decreased smoothly in zero Ca concentration treatment. Leaves'K content was decreased in early stage and then increased in low Ca concentration treatment, but stems'and roots'Ca centent were both decreased in the same treatment. It were smoothly in middle Ca treatment. And the Ca content of leaves, stems and roots in high Ca treatment gradually increased. In the same stress time, along with the increase of Ca concentration, the Ca content of leaves, stems and roots appeared: zero Ca concentration>low Ca concentration >middle Ca concentration > high Ca concentration. The trend was the same as K content. Mg content. Along with the stress time, the Mg content of leaves, stems and roots decreased smoothly in zero Ca concentration treatment, low Ca concentration treatment and middle Ca concentration treatment. While in high Ca concentration treatment , the Mg content of leaves and stems increased, the Mg content of roots decreased first and then increased. In the same stress time, along with the increase of Ca concentration, Mg content change were the same as K content change. Fe content. Along with the stress time, the Mg content of leaves, stems and roots decreased smoothly in zero Ca concentration treatment and low Ca concentration treatment. It was slightly increased in middle Ca concentration treatment. In the same stress time, along with the increase of Ca concentration, Mg content change were the same as K content change.3. The effection on several physiological and biochemical features of Chinese-fir sedlings by the condition of different aluminum concentrations under high calcium concentrationMDA content. Along with the increase of stress time, the MDA content increased significantly in all treatment. Among them, the MDA content was the largest increased in high Al concentration treatment, while the lowest increased in zero Al concentration treatment. However, it overall had little change.in the same stress time, along with the increase of Al concentration, the MDA content gradually increased in all treatment. It appears: high Al concentration> middle Al concentration >low Al concentration > zero Al concentration.SOD activity. Along with the increase of stress time, the SOD activity gradually increased in all treatment at the early stage, but then decreased. In the same stress time, along with the increase of Al concentration, SOD activity is significantly decreased.The CAT activity showed the same trend of the SOD activity, however, it overall had little changed. The POD activity in all treatment increased in early stage, but then decreased. In the same stress time, along with the increase of Al concentration, the POD activity in all treatment were irregular.4 The effection on nutrient absorption of Chinese-fir sedlings by the condition of different aluminum concentrations under high calcium concentrationDifferent Al concentration had different effection on K content, Ca content, Mg content, Fe content separately in leaves, stems and roots of Chinese-fir seedlings under high Ca condition.K content. Along with the stress time, K content of leaves, stems, and roots gradually increased in zero Al concentration treatment, low Al concentration treatment, middle Al concentration treatment. While K content changed somewhat different in high Al concentration treatment, it decreased slightly. In the same stress time, along with the increase of Al concentration, generally, the K content of leaves, stems and roots appears: the highest in Al concentration treatment , and lowest in high Al concentration treatment. Ca content. Along with the stress time, the Ca content of leaves and roots increased smoothly in all treatment, while the Ca content of stems increased in zero Al and high Al concentration treatment with a liitle range, and it decreased at the early stage and then increased in low Al and middle Al concentration treatment. In the same stress time, along with the increase of Al concentration, the Ca content of leaves, stems and roots were irregularly in all treatment. Mg content. Along with the stress time, the Mg content of leaves, stems and roots increased slightly all treatment. In the same stress time, different Al concentration had no significant effection on Mg content in all treatment.Fe content. Fe content change were the same as K content change.The self-protective enzymes system of Chinese-fir seedlings was actived when under Al toxicity, through the physiological protection mechanism, it was able to reduce the hazards of aluminum on its own. Along with the increase of Ca concentration, the MDA centent was significantly decreased and the SOD activity, CAT activity, POD activity were significantly increased under high Al concentration condition. Along with the increase of Al concentration, the MDA content was significantly increased, the SOD activity, CAT activity, POD activity were significantly decreased, while the POD activity change was not significant. Al toxicity in Chinese-fir was significantly increased under high Al concentration condition, while not significantly under high Ca concentration condition. It showed that Ca can alleviate aluminum toxicity to Chinese-fir seedlings to some extent.The K content, Ca content, Mg content, Fe content of Chinese-fir seedlings vegetative tissue significantly decresed under high Al concentration condition, but along with the increase of the Ca concentration, the four elements content decreased more slowly, even increased. It showed that Ca can alleviate aluminum toxicity to Chinese-fir seedlings, and the alleviation ability is positive correlation with Ca concentration. Under high Ca concentration condition, the K content, Ca content, Mg content and Fe content were smoothly increasing, while different Al concentration had no significant effection on them. It showed that low Al concentration had no significant effection on Chinese-fir seedlings.