羊草根际固氮菌数量分析及PGPR的筛选评价

Quantity Analysis of Nitrogen Fixing Bacteria in the Rhizosphere of Leymus chinensis and Screening and Evaluation of PGPR

本试验采用随机选择法从天然羊草草原与人工羊草草地选取健康羊草植株样品,在实验室分离获得羊草根际固氮菌及根际促生菌(PGPR,plant growth promoting rhizobacteria),对PGPR的耐盐、耐碱、泌酸、溶磷、生长素分泌、菌株促生植株生物量、全氮量7项指标进行了测定。结果表明,天然羊草草原固氮菌数量极显著高于人工羊草草地固氮菌数量,二者相差约8倍。对筛选菌株所有指标进行相关性、主成分分析,获得菌株的综合评价排序和优异菌株,其中3个菌株TRTR6、TRTR4和TRTR2表现优异,为下一步生产菌肥提供潜力菌株资源和数据支持。

The method of random selection was applied to samples of Leymus chinensis obtained from natural grassland and artificial grassland to isolate nitrogen fixing bacteria and plant growth promoting rhizobacteria(PGPR)in rhizosphere of Leymus chinensis in the laboratory.Seven indices of the rhizosphere of PGPR bacterial were determined including resistance to salt,alkali,acid secretion,phosphate-solubilizing,hormone secretion,strain grows plant biomass and total nitrogen content.The results showed that the number of nitrogen-fixing bacteria of leymus chinensis was significantly higher in natural grassland than that in artificial grassland,in which the number of the former was increased by 8 times than that in the latter.The correlation and principal component analysis were performed to selected strains to obtain the comprehensive evaluation sequencing and the best strain,in which three strains exhibited excellent qualities,including TRTR6,TRTR4 and TRTR2.This provided potential strain resources and data support for the bacterial fertilizer development in future.