黑松-美味牛肝菌菌根辅助细菌的筛选与鉴定

Isolation and identification of a mycorrhiza helper bacteria strain from the rhizosphere soil of Boletus edulis and Pinus thunbergii

为筛选并鉴定黑松和美味牛肝菌菌根生长的辅助细菌(MHB),进一步探明根际微生物互作关系及其互作对黑松生长的作用,通过分离黑松-美味牛肝菌根际细菌、检测其胞外代谢产物对美味牛肝菌(Be)菌丝生长的促进作用,筛选出MHB潜力菌株。以MHB潜力菌株对松苗的苗高、地径、茎根比、根侵染率的影响,筛选出菌根辅助细菌。通过细菌的形态、生化特性、16S r DNA序列鉴定细菌的种类。结果表明,菌株H12代谢产物可以显著促进Be菌丝生长,双接种Be+H12的黑松苗,苗高提高23.5%,地径提高50.5%,根侵染率提高了472.9%,茎根比下降37.9%。经鉴定,确定菌株H12为蜂房类芽孢杆菌(Paenibacillus alvei)。蜂房类芽孢杆菌对菌根的促生作用明显,可进一步开发为菌塘微生物菌剂。

Boletus edulis (Be) and mycorrhiza helper bacteria (MHB) in the shiroes soil of Pinus thunbergii were isolated and their positive effects on the growth of P.thunbergii were investigated. The potential MHB strains isolated from rhizosphere soil were evaluated , based on the positive effect their extracellular metabolites had on the growth of Be. The MHB strain was screened based on seedling height, ground diameter of the stem, stem root ratio, and root infection rate of P. thunbergii seedlings. The MHB strain was then identified after morphological, biochemical, and physiological analyses, in conjunction with 16S rDNA gene sequencing. The results showed that metabolites exuded by the isolated strain H12 had a significant growth-promoting effect on Be. Co-inoculation of P. thunbergii seedlings with Be+H12 resulted in a 37.9% decrease in stem root ratio. However, the seedling height, ground diameter , and root infection rate increased by 23.5%, 50.5%, and 472.9%, respectively. The strain H12 was identified as Paenibacillus alvei , which exerts a considerably positive effect on mycorrhizal growth. Therefore, it might be developed as a biological fertilizer in rhizosphere soil.