| Improving the growth quality of food crops is the upstream project in the field of food safety research and the source project to ensure food safety.Endophytic bacteria play an important role in the growth and development of host plants,and also participate in the growth,metabolism,biosynthesis and bacteriostasis of the host and other life activities,which have an important impact on the growth and development of the host plants and the quality of the products.Therefore,the study of plant endophytic bacteria is of great significance for agricultural production.Quinoa is an important crop in China,but reports on endophytic bacteria in quinoa are relatively rare at present.In this paper,the roots,stem,leaves and grains of quinoa at mature and seedling stages were sampled,and the endophytic bacteria were analyzed by 16 S and 18 S high-throughput sequencing technology,and three parallel samples were repeated for detection.The community structure of different parts and different periods was analyzed in detail,and the key endophytes in the key growth were analyzed.The main conclusions are as follows:(1)The observed species index,Shannon index and Chao1 index of rhizosphere bacteria in mature stage of quinoa were significantly higher than those in seedling stage(p< 0.05);The observed species index,Shannon index,Simpson index and Chao1 index of the rhizosphere bacteria of quinoa at mature and seedling stages were significantly higher than those of the stem and leaf bacteria of quinoa at mature and seedling stages(p< 0.05);The endophytic bacteria in different positions of quinoa differed greatly,and there was no obvious differentiation in different stages.The diversity and community structure of endophytic bacteria in the root were significantly different from those in the stem,leaf and grain.The abundance and species of endophytic bacteria in the root were much higher than those in the stem,leaf and grain,but there was little difference in the stem,leaf and grain,and the endophytic bacteria structure in the grain was the most similar to that in the stem.The abundance of Cyanobacteria in different loci was compared with that of Cyanobacteria.leaf component >Stem>root;The root showed a trend,while Proteobactrtia showed an opposite leaf<Stem<Root in trends.;The root trend.The community structure of stem and leaf of quinoa was stable at both mature stage and seedling stage.Because the roots of quinoa contained high abundance of antibiotic producing bacteria such as Streptomyces and Amycolatopsis,they jointly maintained the balance of endophytic bacteria system of quinoa plant.Therefore,quinoa has excellent antimicrobial properties and environmental adaptability during its growth and development.(2)The diversity of endophytic fungi and bacteria was significantly different.The diversity difference between seedling stage and mature stage was unclear,and the closer the soil was,the higher the soil diversity was.The soil had a greater influence on the microbial community of quinoa.Ascomycota,Basidiomycota,Mortierellomycota,Zoopagomycota and Kickxellomycota are the three phyla of the genus Ascomycota.Five types of fungi are the main components of endophytic fungi in quinoa.The abundance of Ascomycota at both seedling and mature stages showed a significant difference in root< Stem < leaf.The abundance of Olpidiomycota showed the regularity of in the root >stem > leaf.The content of Basidiomycota was higher in root,stem and leaf of quinoa at mature stage.Thanatephorus is a unique bacterium in the root of mature quinoa,and it is the most abundant microorganism in this sample.The content of Fusarium was higher at seedling stage and lower at mature stage,but it was higher in grain abundance.During the growth process of quinoa,the fungal community structure will appear obvious differentiation,and there will be specific community composition in different stages and different locations.(3)Cyanobacteria,Proteobacteria,Acidobacteria,The three types of bacteria Chloroflexi and Fibrobacteres have significant differences in the samples of each group.KEGG pathway annotation showed that the main functions of endophytic bacteria in quinoa were cell metabolism,environmental information processing and other functions,and the endophytic bacteria in quinoa showed that quinoa had good food safety.Quinoa bacteria are primarily harmful to human health in terms of infection,but their role is also small.In the early stage,the bacterial ecology in the root is not perfect enough,and the bacterial ecology in the mature stage is more conducive to plant growth and food safety.Acidobacteria and Chloroflexi are higher in the root of quinoa than in other samples at mature stage,and they may be the bacteria that play an important role in guaranteeing the growth of quinoa and food safety of quinoa.The abundance of Ascomycota in grain >Leaf >Stem >root is from the soil,the higher the abundance is.Olpidiomycota is an important symbiotic fungus in the root system of quinoa.It mainly exists in the root of mature stage and seedling stage.There is a certain content in the stem of seedling stage,but it disappears after mature stage.The abundance of Mortierella omycota in the mature root system was high.The endophyte-plant-pathogen function mainly occupies a large proportion in leaves at mature and seedling stage,followed by stem.The plant-pathogen function is higher in the mature root and less in other sites,and the roots act as ecological barrier in the mature stage.The function of fungus in the root of quinoa at mature stage and seedling stage is similar,and the function of symbiotic troph is more prominent,and the symbiotic effect of fungus on the root is very obvious. |
