| Based on the productive practice of solar greenhouse in northern China,this subject use over-fertilization simulate salt accumulation of soil in solar greenhouse, studied the effect of different anions on chemical character of soil in greenhouse and growth and metabolism of cucumber, and probed into their injury mechanism to cucumber. The main results were as follows:1 .Compared with CK, all three kinds of fertilizer with different anions increased EC value and decreased pH value of soil solution, the higher fertilization level was. the higher degree of increase or decrease was. The influential sequence of anions on the soil were C1>SO42>NO3".2. Plant height, length between nodes, shoot dry weight, Pn and yield of cucumber in CK treatment were highest, that of cucumber were treated with NO.-T were lower than CK, and the worst was the treatment of Cl". SO42' and Cl" had bad effect on chloroplast in cucumber leaves. Under the conditions of this experiment, in the same treatment type, the higher fertilization level was, the higher inhibition degree to cucumber was.3. From the effect of three kinds of anions on mineral elements absorption of cucumber, we can conclude that there were competitive inhibition relationship among S, N and Cl, especially in leaves. Mn content in cucumber roots stems and leaves were increased significantly when raised fertilization, regardless treatment types. The content of Mn in roots was highest, and that of treated with SO42" was higher than Cl".4.A11 treatments of three kinds anions increased the relative electrolytic leakage.content of MDA and Pro in cucumber leaves, decreased the osmotic potential. The intensity effect was C1">SO42~>NO3" at the same fertilization level, and the higher content of anions was in soil, the clearer this trend was. However, their effect on soluble protein content was not the same; fertilizer with SO42" increased it, fertilizer with Cl" and NO3" decreased it. The effect of different fertilizers on succinic dehydrogenase activity in cucumber roots was not the same, either. At the same treatment level, the difference of root succinic dehydrogenase activity between CK and NO3~ treatment was small, but the fertilization of Cl" and SO4 " reduced succinic dehydrogenase activity significantly, namely, reduced the ability of root absorb, the amount of Cl" and SO42" in soil increased with the raise of fertilization, and their effect on root absorbing ability increased compared with NO3" treatment,5. At the same treatment level, the affective degree of different anions on activity of protection enzyme in cucumber leaves is different, protection enzyme activity in cucumber leaves of all anions treatments were higher than CK. POD activity was the highest when the cucumber were treated with SO42", SOD activity was the highest when treated with Cl". The difference of CAT activity between Cl" and SO42' treatments were not significantly, and both of them were higher than CK and NO3" treatments.6. Raising the three fertilizer's value can all lead to increase ABA content in cucumber leaves, ZR and GA were increased in NO3" and SO42" treatments, and decreased in Cl" treatment.7. The effect of different kinds of salt (KC1, KN03, K2SO4 and PEG) under three different osmotic potential on growth of cucumber was studied in condition of solute culture. The results showed that: compared with three kinds of inorganic salt at the same osmotic potential, PEG had the highest restrain degree on plant height, leaf area and succinic dehydrogenase activity of cucumber. Although amount of soluble sugar and Pro accumulated in cucumber leaves that were treated with PEG was the most, osmotic adjustment ability was the worst. The higher solution density was, the worse effect on cucumber was, no matter what salt involved in this experiment. The main reason of injury three different kinds of anions to cucumber was osmotic stress, and ion stress was minor factor within this experiment scope of salt density and treatment time .
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