盐碱胁迫对大豆根际细菌群落多样性的影响

以野生大豆(Glycine soja)和栽培大豆(Glycine max,吉农18号)为研究对象,通过盆栽试验,以浇灌盐碱液(A)及覆盖盐碱土(B)2种方式分别设置4个不同盐碱浓度的处理,利用变性凝胶电泳技术(DGGE)分析大豆根际细菌的多样性。结果表明:盐碱胁迫下野生大豆和栽培大豆根际中16Sr DNA V3区片段达31条,DGGE指纹图谱中可见,野生大豆和栽培大豆在2种盐碱胁迫处理方式下各有不同的特征条带。适当的盐碱浓度处理能增加野生大豆和栽培大豆根际细菌的丰富度,且覆盖盐碱土处理的野生大豆表现较强的抗逆性。通过对DGGE部分条带的克隆测序与NCBI基因库比对得出部分相对耐盐碱的菌株,如野生大豆中的Altererythrobacter sp.(交替赤杆菌属)、Rhizobium sp.(根瘤菌属)、Psychrobacillus psychrodurans(嗜冷芽孢杆菌属)等和栽培大豆中的Sphingobium sp.(鞘氨醇菌属)、Olivibacter soli(橄榄形菌属)、Uncultured Sphingomonadaceae bacterium(不可培鞘脂单胞菌)、Sphingomonas sp.(鞘氨醇单孢菌属)等。

Effects of Saline Alkali Stress on Diversity of Bacterial Community in Rhizosphere Soil of Soybean

By watering saline solution (A) and covering saline-sodic soil (B),we designed four different saline and alkali concentration treatments,and selected wild and cultivated soybeans for pot experiment.The bacterial community in rhizosphere soil of soybean was investigated by DGGE.The results showed that there were 31 bands of 16SrDNA V3 in rhizosphere soil of wild soybean and cultivated soybean under salt and alkali stress.Among the DGGE fingerprints,wild soybean and cultivated soybean had different characteristics in the two kinds of alkaline conditions (A and B).According to Evenness and Shannon indices,appropriate saline alkali concentration was found to have increased the richness of rhizosphere bacteria of wild soybean and cultivated soybean,and wild soybean showed superior resistance under B treatment.Based on partial specific bands of DGGE and NCBI gene cloning,some tolerant dominant strains were clarified.There are some dominant strains in wild soybean,such as Altererythrobacter sp.,Rhizobium sp.,Psychrobacillus psychrodurans,etc.And Sphingobium sp.,Olivibacter soli,Uncultured Sphingomonadaceae bacterium,and Sphingomonas sp.,are dominant strains in cultivated soybean.Therefore,the results provide a theoretical basis and technical support for screening excellent saline alkali tolerant strains