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作 者 ：丁莉;钟泽璞;李世仪;张崇浩;白克智;匡廷云

期 刊 ：植物营养与肥料学报 1997年 3卷 1期 页码：31-35

关键词：CO2倍增；大豆Bragg结瘤突变系；固氮比活性；单株固氮活性；

摘 要 ：研究了在缺氮条件下，CO₂倍增对大豆（GtycinemaxL.）Bragg及其等基因突变体超结瘤大豆nts382和不结瘤大豆Nod49生长和固氮的影响。结果表明在缺氮条件下CO₂倍增明显提高大生物量和根系结涵量，但对固氮酶活性的影响则随幼苗的生长而异。播种后25天取样结果显示CO₂倍增条件下，Bragg和nts382的固氮比活性和单株固氮活性都显著提高，而其后3天取样的结果没有表现出增加趋势，固氮比活性在nts382反而明显降低。两种CO₂浓度条件下，nts382单株固氮活性高于Bragg，但固氮比活性低于后者。两次测定结果的差异说明植物对CO₂倍增的反应具有很强的时效性;同时表明，CO₂倍增对植物生长和固氮的促进作用不能长期维持。这可能与生物固氮过程本身的复杂性有关。根据本研究结果推测，在未来全球环境变化、CO₂倍增条件下，共生固氮植物可能在生态系统氮素平衡中起到更为重要的作用;并有可能通过育种技术改良固氮农作物，提高农作物产量。

Abstract:Effects of doubled CO₂ on soybean(Bragg) nodulating mutants grown in nitrogen-free medium were studied in the open-top chambers. The main results were described as follows: Under no-nitrogen condition, doubled CO₂ remarkably raised soybean biomass,and increased the number and weight of nodules per plant, but the effects on nitrogenase activities were different as the seedlings growing up. The results of sample 25 days seedling showed that doubled CO₂ sharply stimulated specific nitrogen-fixing activity(SNA) and total nitrogen-fixing activity(TNA). In the following 3 days, such phenomena wasn‘t found, on the contrary SNA was decreased. In two CO₂ levels. TNA was higher in nts382 than in Bragg, but SNA was lower slightly in the fomer than in the latter. The difference between two samplings indicated that the response of plant to doubled CO₂ were influenced by sampling time and plant growth stages. and showed that this Stimulation couldn‘t maintain permanently in the mutant.It was suggested that in the CO₂ doubled environment. symbiotic nitrogrn-fixing plants could play a more important role in nitrogen balance in one ecosystem. on the other hand, legume crops could be improved through breedings in the future.

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