| There are 21.814 million hm2 soil salinization in Xinjiang.Due to the special soil nvironment,salinized soil is often unable to be developed and utilized,resulting in the decrease of soil utilization rate.There are many microbial resources in salinized soil,and microbial community structure and diversity are one of the indicators to evaluate the degree of soil return and soil fertility.Among them,salt tolerant microorganisms play an important role in material transformation,element cycle,energy flow process and ecological restoration of soil ecosystem.In this study,the desert saline soil in the northern Xinjiang autonomous region was used as the material.The traditional isolation and cultivation methods combined with modern molecular technology high-throughput sequencing were used to study the microbial community characteristics and special microbial resources of the soil.The strains with salt tolerance and promoting growth were isolated.The growth of Arabidopsis thaliana was studied by plate and pot experiments The impact of.In order to provide bacteria resources for the special microbial resources of saline soil and the preparation of biological fertilizer suitable for saline soil in Xinjiang.The conclusions are as follows:1.Microbial diversity analysis of saline soil in Wuerhe area of Northern XinjiangThrough high-throughput sequencing technology,it was found that the microbial community is complex and highly diverse,in Wuerhe area,northern Xinjiang.From the proportion of known bacteria,it can be seen that Proteobacteria,Firmicutes,are the dominant bacteria.At the level of phylum taxonomy,Ascomycota is the dominant fungal.Actinomycetes detected the Uncultured microbial resource MB-A2-108 at class level.uncultured?bacterium?f?Ilumatobacteraceae was detected at genus level.2.Screening of culturable and promotive salt tolerant bacteria in saline soil.In this study,8 strains can tolerate Na Cl concentration of 100g·L-1,strain B-6can tolerate Na Cl concentration of 170g·L-1,preliminary identification by 16S r RNA.The B-6 strains belong to the Sediminibacillus sp.,their similarity is less than 97%,and they may be potential new strains.One strain was selected from the salt-tolerant bacteria,which can grow well on Ashby nitrogen-free solid medium,has the ability to dissolve inorganic phosphorus,produces IAA and potassium,and produces ACC deaminase activity(weak positive)Strain W-1,initially identified by 16S r RNA,belongs to the Methylobacterium sp.3.Preliminary study on the growth of Arabidopsis thaliana promoted by Methylobacterium W-1.The best inorganic salt for the growth of strain W-1 is Na Cl,the optimum concentration is 1%-3%,and the highest tolerance concentration is 7%.The best nitrogen source is acid hydrolyzed casein,which can produce up to 40.17 mg·L-1 and the phosphate solubility can reach 29.54 mg·L-1.With the increase of IAA production,the expression of iaa M increased.The chlorophyll content of W-1 seedlings inoculated with Arabidopsis thaliana was better than that of the control group,which significantly promoted the development of its root system,which was reflected in the elongation of the main root,the increase in the number of lateral roots and the development of root hairs.The diversity of microorganisms in saline soil in Wuerhe area of Xinjiang is high, and the species composition is complex.Most of the culturable salt tolerant microorganisms are Bacillus.The screening of salt tolerant growth promoting bacteria W-1has a variety of growth promoting properties,which can significantly promote the growth of Arabidopsis plants and the development of root structure. |
PDF Full Text Request