杨桃根际土壤理化性质及微生物群落特征分析
Physical/Chemical Properties and Microbial Communities in Rhizospheric Soil of Averrhoa carambola Linn.
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摘要: 采用平板培养和磷脂脂肪酸 (PLFAs) 分析方法, 研究20年树龄的台湾软枝杨桃根际与非根际土壤微生物群落差异, 及其与土壤理化性质的相关性。结果表明, 杨桃根际土壤可培养真菌、放线菌、放线菌特征脂肪酸10Me17∶0含量较同层次的非根际土壤多, 土壤上层的可培养微生物及微生物特征脂肪酸16∶0 (细菌) 、18∶1ω9c (真菌) 和10Me17∶0 (放线菌) 均比下层土壤的含量高。微生物PLFAs与土壤有机质含量呈显著或极显著相关的有23种, 包括16∶0、18∶1ω9c和10Me17∶0;与土壤总氮、总磷、总钾相关的有1820种;与pH值和含水量相关的PLFAs种类较少。Abstract: Microbial communities in the soil of the rhizosphere and non-rhizosphere of Averrhoa carambola Linn cv.Taiwan soft-branch carambola were compared by microorganism-culturing and the application of the phospholipids fatty acids biomarkers (PLFAs) .Correlation and soil chemistry were also studied.Significantly more cultural fungi and actinomycetes as well as PLFA 10Me17∶0related to actinomycetes were found in the rhizospheric than in the non-rhizosphere soil of a same layer.The quantities of PLFAs 16∶0related to bacteria, 18∶1ω9crelated to fungi and 10Me17∶0related to actinomycetes were significantly higher in the upper-than in deep-layer of the soil.The quantities of organic matters significantly correlated with the 23PLFAs biomarkers, including 16∶0, 18∶1ω9cand10Me17∶0.Total nitrogen, potassium and phosphorus significantly correlated with the 18-20PLFAs biomarkers.Only a few PLFAs biomarkers showed significant correlation to the soil pH or water content of the soils.