潜在促生菌Bacillus tequilensis U36的产IAA特性及其对辣椒的促生效果

IAA production characteristics and growth-promoting effects on pepper of potential plant grouth-promoting rhizobacteria(PGPR) Bacillus tequilensis U36

对从土壤中分离到的一株潜在根围促生菌U36进行了系统分析,通过形态学、生理生化特性及16S r RNA分析鉴定其为特基拉芽孢杆菌Bacillus tequilensis。盆栽试验发现,U36对植物生长有促进作用,而且在正常土壤中植株的生长优于无菌土。但就促生效率而言,在灭菌土中加入U36后的促生效率高于正常土中的促生效率:正常土中U36对辣椒根长、根重、茎长、茎重和叶面积的促进效率分别达到47.7%、37.5%、21.5%、69.2%和8.1%;而在灭菌土中,辣椒根长、根重、茎长、茎重和叶面积的促进效率分别为49.2%、58.8%、25.7%、58.2%和24.1%。通过研究发现U36不仅具有固氮、解磷的功能,还可产生促生长物质吲哚乙酸(IAA),且IAA的产生具有色氨酸依赖性。该菌株的优良促生特性可以作为潜在促生菌用于生物肥料研发,具有很好的应用价值。

We systematically analyzed a potential plant growth-promoting rhizobacteria （ PGRP ） U36, which was separated from soil. This strain was eventually determined to be Bacillus tequilensis through the morphological, physiological and biochemical properties and 16S rRNA assay. Through the pot experiment, we found that U36 promoted pepper growth, which was better in normal soil than in sterilized soil, but the growth promoting efficiency was much higher in sterilized soil than in normal soil after applying U36. In normal soil, the promoting efficiencies of U36 on root length, root weight, stem length, stem weight and leaf area of pepper were 47.7%, 37.5%, 21.5%, 69.2% and 8.1%, respectively. While in sterile soil, the promoting efficieneies were 49.2%, 58.8%, 25.7%, 58.2% and 24.1%, respectively. Besides, U36 not only had the functions of nitrogen fixation and phosphate-solubilizing, but also could produce the growth promoting substance IAA, and the generation of IAA had tryptophan dependence. With the excellent growth-promoting effect, U36 can be used as a potential PGPR for the development of biological fertilizer, which has a good application value.