| Camellia yuhsienensis Hu is an important woody oil plant,with thin shells,high oil content and high disease-resistant characteristics.It is the excellent breeding germplasm which flower in spring.In recent years,it has been paid more attention in scientific research and production.Diversity and structure of microbial communities are the most sensitive biological indicators.Microorganisms directly impact soil physicochemical properties,nutrition absorption and utilization of plant and the occurrence of soil-borne disease.In order to study the microbial community structure and the dominant microorganisms in the rhizosphere soil of C.yuhsienensis,soil samples were collected from two sites,Wangchen(W)and Youxian(Y)in four seasons in one year,respectively.The non-rhizosphere soil and the rhizosphere soil of Camellia oleifera Abel were the controls.Combining microbial gene sequences and soil physicochemical properties to research the microbial community and specific microorganisms in the rhizosphere soil of C.yuhsienensis.The main findings are as follows:1.Content of available phosphorus(AP),total phosphorus(TP),available potassium(AK),total potassium(TK),ammonium nitrogen(AMN),nitrate nitrogen(NN)and total nitrogen(TN)content in the rhizosphere soil of C yuhsienensis were 0.18-9.96 mg/kg?350-480 mg/kg?70-159 mg/kg?254-373 mg/kg?29-73 mg/kg?4.9-57.9 mg/kg and 549-1 151 mg/kg respectively,which were significantly lower than those in the rhizosphere soil of C.oleifera.pH in the rhizosphere soil of C yuhsienensis was 4.0-4.7 which was significantly higher than that in the rhizosphere soil of C.oleifera.Content of available nitrogen(AN),total organic carbon(TOC)and soil moisture content(SMC)in the rhizosphere soil of C.yuhsienensis were 43-166 mg/kg?10.5-14.7 g/kg and 21%-32%,respectively,which were similar to those in the rhizosphere soil of C.oleifera.The content of TP,AN,TN and TOC were significantly higher in the rhizosphere soil of C.yuhsienensis than those in the non-rhizosphere soil.2.The soil bacterial Sobs,Ace,Chao 1,Shannon and Simpson diversity index in the rhizosphere of C.yuhsienensis were 1206-2238,1482-2778,1516-2802,7.3-8.5 and 0.9610-0.9922,respectively.Bacterial diversity in the rhizosphere soil of C yuhsienensis was significantly affected by seasonal and regional dynamics.The soil fungal Sobs,Ace,Chao 1,Shannon and Simpson diversity index in the rhizosphere of C.yuhsienensis were 260-474,367-598,376-597,3.1-5.8 and 0.5587-0.9558,respectively.Seasonal and regional dynamics had no effect on soil fungal diversity in the rhizosphere of C.yuhsienensis.3.The analysis of microbial community structure indicated that Chloroflexi,Proteobacteria,Acidobacteria,Actinobacteria,Planctomycetes and Firmicutes were the dominant bacteria at phylum level in the rhizosphere soil of C.yuhsienensis.There were significant differences of dominant bacteria at class,genus and species level among different seasons.Ascomycota and Basidiomycota were the dominant fungi at phylum level in the rhizosphere soil of C.yuhsienensis.There were significant differences of dominant fungi at class,genus and species level among different seasons.4.Correlation analysis results showed that the correlations between environmental factors and microorganisms were significantly affected by seasonal,regional and sampled position dynamics.The mean of monthly temperature(TEM)was the predominant influence factor on bacterial diversity.There were significant negative correlations between bacterial diversity and TEM both in Wangcheng and Youxian rhizosphere soil of C.yuhsienensis The soil bacterial diversity and dominant bacteria in the rhizosphere soil of C.yuhsienensis were positively correlated with SMC while negatively correlated with content of AK.In conclusion,there were significant differences of microbial community structures between C.yuhsienensis and C.oleifera and those differences were dramatically regulated soil physicochemical properties which varied with seasonal and regional dynamics. |
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