Effects Of Different Management Strategies On Soil Microbial Diversity And Insect Community In Tea Plantations

Tea is one of the important economic crops in China.The number of pests in tea plantations and the functions of microbial communities directly affect tea tree growth and yield.At present,along with the current situation of non-standard domestic management strategies,soil nutrient status and microbial community structure have undergone great changes,which has become an important factor affecting the sustainable development of the tea industry.Scientific and rational management strategies can improve the species richness of the tea plantation macro-ecosystem and micro-ecological system,increase the stability of the tea plantation ecosystem,and provide strong resistance to the outbreak of pests and diseases invasion,thereby improving the yield and quality of tea.We have studied the tea plantation under different management strategies,and the research results are as follows:1.The influence of long-term application of different fertilizers on soil microbial diversity and community structure of tea plantations remains unclear.Soil samples were collected from 5 large experimental tea plantations under long-term different fertilization treatments in central south of China.The treatments were organic fertilizer(OF),chemical fertilizer(CF)and nonfertilizer(NF).High-throughput 16 S r RNA gene Illumina sequencing in combination with microbial network analysis were conducted to compare the different fertilization treatments.The results showed that soils under OF treatment had higher levels of microbial diversity compared to soils under other treatment regimes.PCoA results revealed a clear separation among the groups of tea plantation soils under three treatment regimes.Relationship analysis between soil properties and microbial communities showed that pH and NO3-N content were key physicochemical factors that significantly influenced microbial diversity and community structure.Furthermore,network analysis indicated that the network of OF treatment soils exhibited more functionally interrelated microbial modules than soils with CF treatment and that the topological roles of characteristic OTUs and key microbial organisms were significantly different between CF and OF treatments.In addition,the relative abundances of organisms belonging to chemoheterotrophy,fermentation,nitrogen fixation,and aerobic nitrite oxidation functional groups in tea plantation soils under OF treatment were higher compared with CF treatment(p < 0.05).It was concluded that OF treatment could improve the microbial diversity and community structure,and alter the microbial network structure and potential function in tea plantation soils.This study provides a first glimpse into the microecological effect guiding tea plantation soil community modulated by different fertilization systems.2.Plant cultivar impacts the soil microbiome.Soil microbiome can largely contribute to plant growth,health and agricultural production.However,the soil microbial community structures and diversities in relation to different tea(Camellia sinensis)cultivars remains unknown.By utilizing high-throughput 16 S rRNA gene Illumina sequencing,we systematically studied and compared the microbial community composition,structure and diversity in the bulk soils of 5 tea cultivars cultivated in a tea plantation for 15 years in central south of China.The tea cultivars were C.sinensis cv.Bixiangzao(BXZ),C.sinensis cv.Zaofengchun(ZFC),C.sinensis cv.Rougui(RG),C.sinensis cv.Maoxie(MX)and C.sinensis cv.Baihaozao(BHZ).There were significant differences in soils community for the relative abundances of six dominant phyla Actinobacteria,candidate division WPS-2,Chloroflexi,Planctomycetes,Proteobacteria and Thaumarchaeota between both of BXZ,BHZ and the other three cultivars(p < 0.05).Relative abundance of genus Nitrososphaera in soils of BXZ was significantly higher than the soils of others tea cultivar.According to Chao1 and Richness diversity indices,BXZ soils had the highest microbial alpha-diversity.The principal coordinates analysis(PCoA)of microbial communities based on weighted unifrac distances revealed a clear separation between BXZ and other cultivar soils,while there was a partial overlap among ZFC,RG,MX and BHZ cultivar soils.Pearson relationship analysis showed that the pH value,moisture and TOC,TN,AP contents were major soil factors to influence the microbial diversity of different tea cultivars.Functional Annotation of Prokaryotic Taxa was adopted to predict that the percent relative abundances of aerobic ammonia oxidation,nitrification and fermentation functional bacteria in the soils of BXZ cultivar were significantly higher compared with other cultivars.This study systematically assesses the differences for soil microbial community structure and diversity among different tea cultivars and provides theoretical basis for future studies on rhizosphere effect guiding the tea plantation soil community influenced by different tea cultivars.3.In order to compare the differences of arthropod community in tea plantation under different management practices,a systematic investigation and analysis of arthropods,major pests and natural predator insects in organic,non-pollution and common tea plantations in Hunan Province were conducted.There are some differences in arthropod community of organic,non-pollution and common tea plantation habitats.The three tea plantations are all dominated by the Order Homoptera,Lepidoptera,Coleoptera,Hymenoptera,Odonata and Corrodentia.The four main pests of Aleurocanthus spiniferus(Quaintanca),Acaphylla theae Watt,Ectropis oblique hypulina Wehrli and Jacobiasca formosana accounted for 59.83%,56.17%,and 71.43% of the total number of arthropods in organic,non-pollution and common tea plantations,respectively.In addition,the proportion of natural enemies of insect accounted for 10.76%,7.59% and 5.79%,respectively.The results showed that the species richness and diversity index of organic tea plantation were significantly higher than those of non-polluted and common tea plantations.The quantity of pests in organic plantation was obviously lower than that of the other two tea plantations,and the frequency of major natural enemies of insect in organic plantation was significantly higher than other two tea plantation.