玉米根际高效溶磷菌的筛选、鉴定及促生效应研究

为获得玉米根际高效溶磷促生菌(Plant growth-promoting rhizobacteria,PGPR)并明确其促生特性,采用选择培养方法从玉米根际土壤筛选出优良PGPR 菌株,测定其溶磷及分泌吲哚乙酸(IAA)的能力,并对优良菌株进行鉴定;采用盆栽试验研究菌株的促生作用。结果分离到2 株优良PGPR 菌株CH07和FD11,其溶磷量分别为368.5 mg/L和321.5 mg/L,产IAA量分别为30.93 mg/L和15.93 mg/L。形态学特征、生理生化特征和16S rDNA 序列分析结果表明,CH07为芽孢杆菌属(Bacillus aryabhattai),FD11为链霉菌属(Streptomyces maritimus)。最后通过盆栽试验对这2株细菌分离物的促生效果进行比较,结果发现,CH07、FD11,尤其是CH07与FD11的复合物,对苋菜的株高及地上部鲜重有积极作用,可作为研制生物肥料的优良菌株资源。

Screening and Identification of Phosphate Solubilizing Bacteria from Maize Rhizosphere Soil and Its Growth Promoting Effect

In order to obtain plant growth promoting rhizobacteria(PGPR)in maize and clarify its growth-promoting characteristics,PGPR strain were screened from maize rhizosphere soil samples.Then the P-solubilizing characteristics and IAA-producing ability of preferred strains were studied using soil pot experiment.The strains were further identified and their growth-promoting effects were investigated in pot experiment.As results,2 excellent PGPR strains were isolated and named as CH07 and FD11,and their solubilized phosphorus reached 368.5 mg/L and 321.5 mg/L,the produced IAA(indole acetic acid)were 30.93 mg/L and 15.93 mg/L,respectively.According to the results of morphologic characteristics,physiological biochemical properties and phylogenetic analysis of 16S rRNA genes,CH07 was identified as Bacillus aryabhattai and FD11 as Streptomyces maritimus.Finally,the growth promoting effects of the two bacterial isolates were compared by pot experiment.The results showed that CH07,FD11,especially the mixture of CH07 and FD11,had a positive effect on the plant height and shoot fresh weight of amaranth,and could be used as an excellent strain resource for the development of biological fertilizer.