花生根际产IAA菌的筛选鉴定及其效应研究

Isolation and identification of IAA-producing strains from peanut rhizosphere and its promoting effects on peanut growth

植物根际产IAA菌能够分泌吲哚乙酸(IAA)促进生长,提高作物产量。为从砂质潮土中的花生根际筛选高产IAA的根际促生菌,本研究首先从长势较好的花生根际筛选出单株菌落,对其分泌IAA能力进行定性和定量分析,并通过16S r DNA基因序列配合生理生化特征鉴定所筛选的高产IAA菌株,然后设置单因素试验,探究适宜菌株生长和发酵的条件,最后通过花生盆栽试验验证其促生能力。结果表明,共筛选出5株产IAA的促生菌菌株,其中菌株HS10的IAA产量最高,被鉴定为特基拉芽孢杆菌。单因素试验表明,HS10最适培养条件是培养温度30℃,时间20 h,初始p H 8,装液量25 m L/250 m L,碳源为果糖,氮源为硝酸钾。盆栽试验表明,接菌花生植株长势明显优于对照,HS10对花生具有良好的促生效应。

Some plant rhizosphere bacteria can secrete indoleacetic acid（ IAA） to promote the plant growth and increase crop yield. This research aimed to screen IAA- producing strains from rhizosphere of peanut in sandy soil,and to analyze their promoting effect. 5 IAA- producing strains were isolated from rhizosphere of a healthy peanut plant. Among them,strain HS10 had the highest IAA- production ability and was identified as Bacillus tequilensis by 16 S r RNA gene sequencing combined with its physiological and biochemical test evaluation. HS10 produced maximum IAA at 24 h of incubation with optimum conditions as 30℃,pH8,fluid volume 25 mL /250 mL,fructose and potassium nitrate as carbon source and nitrogen source respectively. Pot experiment demonstrated that HS10 significantly promoted plant growth and root system of peanut compared to the control.