关键词: 退化, 高寒草甸, 碳源代谢, 酶, 土壤微生物量碳氮

Abstract: In order to screen out the better ratio of black soil and saline-alkali soil for planting rice Changbai 9, the effects of five kinds of soil on the osmotic substances and membrane injury of Changbai 9 leaves, panicle stem and sheath after heading were studied. The results showed that free amino acid, proline and soluble protein contents of treatment C (black soil∶alkaline soil =1∶1) were higher than that of other soil combination treatments. When the ratio of black soil and salinealkali soil was 3∶1, the soluble protein and soluble sugar contents were consistent with black soil, but free amino acid and proline contents were closer to that of treatment C. The contents of osmotic adjustment substances of different organs were relatively small after heading of Changbai 9 grown in the original salinealkali soil, and MDA content and O₂^-_· production rate were obviously higher than in other treatments. The accumulation amounts of osmotic adjustment substances of different organs of Changbai 9 from heading to mature were in the order of leaf > panicle > precedes stem > sheath. This suggested that the original salinealkali soil with a high Na⁺ concentration and a high pH value reduced the osmotic adjustment ability and accelerated the injury of membrane of Changbai 9. The ratio of black soil to salinealkali soil at 1:1 or higher can effectively regulate the soil Na⁺ concentration and pH value, and enhance the osmotic adjustment ability of Changbai 9 organs, especially for leaf and panicle.

Key words: degradation, soil microbial biomass C and N, carbon metabolic index, enzymes., alpine meadow