Physicochemical Properties And Bacterial Diversity Of Tea Plant Rhizosphere Soil In Hanzhong

Camellia sinensis is one of the important perennial economic crops in Hanzhong and even the whole country,mainly based on continuous single planting mode.Increased tea planting years will result in decreased soil fertility of tea trees,increased pathogenic microorganisms,continuous cropping obstacles,and severely affect the normal growth of tea trees.To reveal the physical and chemical properties of tea tree rhizosphere soil and the characteristics of bacterial communities under different tea planting years.This paper analyzes the physicochemical characteristics of tea tree rhizosphere soil in five major tea producing areas(Zhenba,Chenggu,Mian County,Ningqiang,Xixiang)of Hanzhong area under different tea planting years(5 years,10 years,20 years)Nature and bacterial diversity,and explain the relationship between the two,in order to provide a basis for the development and utilization of tea tree rhizosphere microbial resources,improve soil fertility,green and healthy tea planting.1.Using the cultivation method to study the bacterial composition and diversity of the rhizosphere soil of tea trees under different years of planting tea in Hanzhong area,a total of 480 strains of bacteria,Firmicutes(Firmicutes,84.8%)and Bacillus(Bacillus,70.8)were isolated %)At 5 years,10 years,and 20 years,the dominant genus is relatively large(except for the genus Proteobacteria and Enterobacteria at 5 and 10 years in Zhenba area).Zhenba and Chenggu have the most abundant bacterial diversity at 10 years of tea planting,Mian County and Ningqiang have the most abundant bacterial diversity at 20 years of tea planting,and Xixiang area has 5 years of tea cultivation Bacterial diversity is the most abundant.The rhizosphere bacterial composition of tea trees in Zhenba and Chenggu areas was similar to that of tea trees at 5 years and 20 years,while that of Mianxian,Ningqiang and Xixiang was similar to that at 10 years.2.Using high-throughput sequencing technology to obtain 1008794 effective sequences from 15 soil samples,combined with the ? diversity index shows that Hanzhong tea tree rhizosphere soil bacterial composition is rich,can provide data for the development and utilization of tea tree rhizosphere microbial resources.The types and changing trends of the bacterial dominant phylum of tea rhizosphere soil in 5 plots within 3 years are different,which can reflect the evolution of tea soil fertility in this area to a certain extent.On the whole level,Proteobacteria and Acidobacteria are the dominant bacteria,and Delftia and Udaeobacter are the dominant bacteria.The increase of tea planting years will cause significant changes in the rhizosphere bacterial diversity of tea trees.The rhizosphere bacterial diversity of Zhenba tea trees is 10 years> 20 years> 5 years,and that of Chenggu and Mian County is 20 years> 10 Year>5 years,Ningqiang tea tree rhizosphere bacterial diversity is 5 years>10 years>20 years,Xixiang tea tree rhizosphere bacterial diversity is 10 years>5 years>20 years.3.By measuring the physical and chemical properties of the rhizosphere soil of Hanzhong tea trees,it can be concluded that the increase in the number of years of planting tea has a greater impact on the water content of the rhizosphere soil of Hanzhong tea trees,and less on the pH value.The 15 soil samples have a water content ranging from 2% to 33%,with an average value of 12%.The average water content(24.98%)and the extreme water content(12.69%)in the Mian County area are the highest,while the average water content(4.47%)and the extreme water content(2.81%)in the Ningqiang area are the lowest.The pH range is 4.56~5.33,the average value is 5.06,the average pH value of urban solid is the lowest(4.55),and the average pH value of Xixiang is the highest(5.29).Soil organic carbon,total nitrogen,hydrolyzable nitrogen,total phosphorus,available phosphorus,total potassium,and available potassium range from 8.07 to 31.25,0.78 to 2.51,0.10 to 0.26,0.57 to 1.55,0.002 to 0.056,11.50 to 20.75 and 0.095~0.491 g/kg.The average values were 15.99,1.45,0.79,14.62,0.16,0.02,0.22 g/kg.With the increase of tea planting years,the trend of nutrient elements in the rhizosphere soil of Hanzhong tea trees is different,and the relative change of available phosphorus is the largest.With reference to the tea soil fertility standard,it is concluded that the pH value of the tea rhizosphere soil in Hanzhong is moderate,and the nitrogen,phosphorus,and potassium contents are relatively rich.On the whole level,the increase in the age of tea planting has little effect on the soil fertility level,and some major producing areas should appropriately increase the input of available phosphorus when the age of tea planting is 10 years.4.Combining the results of the principal component analysis with the bacterial diversity obtained by the cultivation method and high-throughput sequencing analysis fully shows that the content and types of soil factors in the rhizosphere of tea trees have a significant impact on the diversity of bacteria.According to the Spearman heat map analysis,there is a significant or extremely significant correlation between the physical and chemical properties of the soil and most bacterial communities.There is a very significant negative correlation between the soil pH and most bacterial communities.Most bacterial communities have a very significant positive correlation.Combining RDA analysis and Mantel test analysis,it is concluded that soil pH and available phosphorus content have a greater impact on tea plant bacterial communities,while soil water content and total potassium content have less effect on tea plant bacterial communities.