The Effect Of Synergy Between Aluminum And Nutrition On Physiological And Biochemical Features Of Chinese-fir Seedlings

Chinese ftr is one of the most important afforestation tree species in the southern of China. Many research results show that fir is not endure aluminum poison; The southern soil is acidic soil and rich in iron and aluminum, aluminum content is high in the soil, aluminium poisoning has become one of the restrictive factors which can influence the normal growth and forest sustainable management of Chinese fir. How to repair the damaged Chinese fir plantation ecosystem and realize the Chinese fir plantation forest sustainable management, become the toxicology Chinese fir plantation ecology research hotspot. This paper used the fir as the research object, using pot simulation organism cultivation method, through the analysis of the effect of aluminum and nutrient combined action of different period of Chinese fir seedlings to oxidase activity and chlorophyll content and chlorophyll fluorescence and physiological and biochemical index, the results of the study is helpful to lay the theoretical foundation and technical support for revealling physiological response mechanism of fir seedling to aluminum and nutrient composite processing, prevention and control Chinese fir plantation aluminium poisoning, realize the forest sustainable management of Chinese fir plantation.The study results are as follows:(1) Effect of different nutrient concentration on the physiological properties of Chinese fir seedlings under the high aluminum concentration stress.Under high aluminum concentration stress, the enhancement effect of high nutrient processing to the SOD, CAT and PPO activity is obvious, the enhancement effect of middle nutrient processing to POD activity is obvious. High and middle nutrient processing decrease the damage of aluminum on membrane system and reduced the MDA content obviously, and remain lower than control level, low nutrient treatment on MDA content reduces is not obvious. Under middle and low nutrient processing, the chlorophyll a contents were increased at first, then decreased, hlorophyll b and total chlorophyll were increased at first, then decreased and rising trend,chlorophyll a, b and the total content are higher than the ck level; Under high nutrient processing, chlorophyll a, b and total content are lower than control level. Different nutrient treatment’s impact on chlorophyll fluorescence parameters Fv/Fm is not obvious.Under high nutrient processing, the Fo, Fm of Chinese fir seedling increased at first, then decreased and rising trend, Fv were increased at first, then decreased trend, but Fo, Fm and Fv always higher than those of control level.(2) Effect of different nutrient concentration on the physiological properties of Chinese fir seedlings under the middle aluminum concentration stress.Under middle aluminum concentration stress, exogenous nutrient enhance the fir seedling antioxidant enzyme activity in a certain extent,including SOD, POD and PPO activity of Chinese fir seedlings were enhanced obviously, high nutrient processing Chinese fir seedling CAT activity enhancement effect is obvious. Under high, middle and low nutrient processing, fir seedlings in the MDA content increased at first, then decreased change trend, and the middle nutrient processing in Chinese fir seedlings make the MDA content consistently lower than control level,which ease the stress caused by the membrane damage effect is obvious. Under high and middle processing, the content of chlorophyll a reduced continuously, the content of chlorophyll b first decreases then raised trend, and the total content of chlorophyll is increased at first, then decreased trend, and the chlorophyll a, b and total total content is higher the ck level;High and low nutrient processing improve the fir seedling fluorescence parameter Fv/Fm to a certain extent, the fluorescence parameter Fv/Fm of middle nutrient processing has been consistently lower than control level, low nutrient processing Chinese fir seedling fluorescence parameters Fo, Fm and Fv increase effect is helpful.(3) Effect of different nutrient concentration on the physiological properties of Chinese fir seedlings under thelow aluminum concentration stress.Under low aluminum concentration stress, exogenous nutrient can enhance fir seedling’s SOD, POD, PPO activity, and overall higher than those of control level, the middle and low nutrient treatment effect is better; High, middle and low nutrient processing of Chinese fir seedling’s CAT activity overall lower than control level, the high and low nutrient processing in a nutrient handle.Middle and low nutrient treatment can reduce the MDA content of Chinese fir seedlings and keep lower than control level; Under High nutrient processing, the MDA content of Chinese fir seedlings increased at first, then decreased change trend, and always higher than those of control processing, alleviate aluminum stress effect is not obvious; Under high nutrient processing, Chinese fir seedlings’chlorophyll a and b content and total content generally higher than those of control level, middle and low nutrient processing of Chinese fir seedlings’ chlorophyll a, b and total overall lower than control level; High and low nutrient processing to improve fir seedling fluorescence parameter Fv/Fm effect is obvious, the middle nutrient processing of Chinese fir seedlings’fluorescence parameter Fv/Fm has been consistently lower than control, middle and low nutrient processing of Chinese fir seedlings’fluorescent parameters Fo, Fm and Fv is increased at first, then decreased and trend of the rising; High nutrient processing of Chinese fir seedlings’ fluorescence parameters Fo, Fm and Fv after the first reduce then rised, the earlier stage of stress is lower than control level, stress later higher than the control level.In short, under high, middle, and low concentration aluminum stress, exogenous nutrient can enhance Chinese fir seedlings’antioxidant enzyme activity, reduce aluminum stress on membrane system damage, reduce MDA production, to maintain the content of chlorophyll fluorescence parameters and stability. Under different aluminum stress, different nutrient concentration play relief effect exist certain differences.