中国农业科学2012，Vol.45Issue(8)：1532-1544,13.DOI:10.3864/j.issn.0578-1752.2012.08.009
农田环境中固氮菌的促生潜能与分布特点
Growth Promotion Potential and Distribution Features of Nitrogen-Fixing Bacteria in Field Environments
摘要
Abstract
[Objective! The objective of this experiment is to determine the dominant species and phylogenetic position of nitrogen fixing bacteria in crop rhizosphere and field environments, and to screen for nitrogen-fixing bacteria with growth promotion potential. [Method]Nitrogen-free medium was used to culture nitrogen-fixing bacteria and nitrogenase activity was determined with acetylene reduction assay. Confrontation method was used to test antagonistic bacteria against plant pathogenic fungus. ACC (1-aminocyclopropane-l-carboxylate) nitrogen source was used to test ACC deaminase. 16S rDNA was amplified by PCR and 16S rDNA sequence was analysed with MEGA software. [Result] Nitrogenase activity of the 94 tested strains ranged from 0.99 to 180.59 nmol C2Ht/h-mg protein. Fourty-two strains accounting for 44.7% of the tested strains showed nitrogenase activity above 10 nmol C2Ht/h4mg protein. Paenibacillus and Bacillus were main groups, and their percentages were 33.0% and 26.6% of the tested strains, respectively. Six strains accounting for 6.4% of the tested strains showed antagonistic actions against plant pathogenic fungiSclerotinia scleroliorum, Gibberella zeae and Verticillium dahliae with the inhibitory rate from 23.9% to 65.9%. Twenty strains accounting for 21.3% of the tested strains produced ACC deaminase with activity ranging 0.33 to 21.98 umol a-ketobutyric acid/h-mg protein, which were identified as Bacillus, Paenibacillus, Rhizobium, and extensively distributed in crop rhizosphere and field environments. I Conclusion] The dominant species of nitrogen-fixing bacteria in crop rhizosphere and field environments belong to the genus Paenibacillus and Bacillus. Most of the nitrogen-fixing bacterial strains possess strong potential for nitrogen fixation, part of them possess potential for growth promotion, and a few of them possess potential for disease resistance. The potential strains belong to Paenibacillus, Bacillus and Rhizobium, and extensively colonized in crops with no specificity.关键词
固氮菌/固氮酶/抗菌/ACC脱氨酶/16S rDNAKey words
nitrogen-fixing bacteria/nitrogenase/pathogenic fungus resistance/ACC deaminase/16S rDNA引用本文复制引用
孙建光,胡海燕,刘君,陈倩,高淼,徐晶,周义清..农田环境中固氮菌的促生潜能与分布特点[J].中国农业科学,2012,45(8):1532-1544,13.基金项目
国家公益性行业(农业)科研专项(201203045) （农业）
