三株产吲哚乙酸根际促生芽孢杆菌的筛选鉴定及其促生作用

为丰富具有产吲哚乙酸(IAA)功能的芽孢杆菌菌种资源,开发高效根际促生微生物菌肥,从玉米、生菜和绿化带植被的根际土壤中筛选产IAA的芽孢杆菌,最终获得3株高效产IAA的菌株——YC9L、YC3172和YC5064,其IAA产量分别为46.72、79.75、67.55 mg·L^-1。对其进行理化特性和16S rDNA序列分析,鉴定YC9L和YC3172菌株为大猩猩芽孢杆菌(Bacillus massiliogorillae),YC5064菌株为栗褐芽孢杆菌(Bacillus badius)。玉米种子发芽试验显示,YC9L和YC5064菌株对玉米种子发芽,以及幼苗生长具有促进作用。生菜盆栽试验显示,YC9L、YC3172、YC5064菌株对生菜植株生长具有促进效果。玉米盆栽试验显示,YC9L、YC3172、YC5064菌株对玉米植株生长有良好的促进效果,且以YC9L的效果最优。YC9L、YC3172、YC5064菌株均具有解钾能力;YC9L和YC3172菌株具有解磷能力;YC9L、YC3172、YC5064菌株对镉、锌、铜均具有耐性。

Isolation and identification of three indole-3-acetic acid producing plant-growth-promoting rhizosphere Bacillus sp. and their growth-promoting effects

In order to enrich the resources of strains with the function of indole-3-acetic acid (IAA) production, hence to develop high-efficiency plant-growth-promoting microbial fertilizer, three strains with high IAA production ability were isolated from the rhizosphere soil of maize, lettuce and green belt vegetation plant, and were encoded as YC9L, YC3172 and YC5064, respectively. The IAA production of YC9L, YC3172 and YC5064 reached 46.72, 79.75, 67.55 mg·L^-1, respectively. According to the characteristics and 16S rDNA identification, YC9L and YC3172 strains were identified as Bacillus massiliogorillae, and YC5064 strain was identified as Bacillus badius. The maize seed germination test showed that YC9L and YC5064 strains could promote seed germination and seedling growth of maize. The lettuce pot experiment showed that YC9L, YC3172, YC5064 strains had obvious promoting effect on the growth of lettuce. The maize pot experiment showed that YC9L, YC3172, YC5064 strains could promote the growth of maize. In addition, YC9L, YC3172 and YC5064 strains all had the ability to dissolve potassium. YC9L and YC3172 strains had the ability to dissolve phosphorus. YC9L, YC3172 and YC5064 strains had resistance to Cd, Zn and Cu.