一株菌草内生细菌的分离鉴定及促生特性

Isolation,identification and growth-promoting characteristics of an endophytic bacteria from JUNCAO

通过研磨组织、稀释分离等方法,从巨菌草的健康叶片中分离、筛选出1株具有溶磷和分泌吲哚乙酸能力的内生细菌,命名为FJU3,并对其生理生化特性、16S rDNA序列进行测定和分子生物学鉴定,也研究了其对盆栽玉米的促生效果.结果表明:菌株FJU3具有一定的溶磷能力,其分泌吲哚乙酸的质量浓度达到了14.2 mg·L^(-1),且显著高于其他菌株;经形态特征和分子生物学鉴定该菌株为解淀粉类芽孢杆菌(Paenibacillus amylolyticus);菌株FJU3在产铁载体、接触酶、解硅酸盐等生理生化特性试验中均为阳性反应;玉米盆栽促生试验结果表明,促生效果比较显著的是地上部鲜质量和株高,与对照组相比,分别增加了76%和41%.

An endophytic bacterium with phosphorus solubilizing and indoleacetic acid(IAA)secreting ability,termed FJU3,was isolated from the healthy leaves of Cenchrus fungigraminus and screened by grinding tissue and dilution isolation method.And the analyses on its physiological and biochemical characteristics,16S rDNA sequence for molecular biology identification and growth-promoting effects on potted maize were further performed.The results showed that strain FJU3 had certain phosphorolysis ability,and the concentration of IAA,it secreted reached 14.2 mg·L^(-1),which was significantly higher than that from other strains.It was identified as Paenibacillus amylolyticus by morphological and molecular characteristics.FJU3 strain was positive in iron carrier production,contact enzyme,and silicate solubilization tests.It demonstrated growth-promoting effect on potted maize,resulted in significantly greater above-ground fresh weight and plant height,up by 76%and 41%,respectively.