黄土高原天然和人工油松林根际土壤解磷细菌群落特征及其功能  

Community characteristics and functions of phosphate-solubilizing bacteria in rhizosphere soil of natural and planted Pinus tabuliformis forests on the Loess Plateau,Northwest China

作　　者：朱颖 库永丽 刘金良[1] Le Thi Hien 赵忠[1] ZHU Ying;KU Yong-li;LIU Jin-liang;Le Thi Hien;ZHAO Zhong(College of Forestry,North-west Agriculture and Forestry University,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学林学院,陕西杨凌712100

出　　处：《应用生态学报》2021年第9期3097-3106,共10页Chinese Journal of Applied Ecology

基　　金：国家重点研发计划项目(2016YFC0501706-01)资助。

摘　　要：为了揭示油松-根系微生物的互作关系及其对油松林分稳定性的影响,本研究选择陕西省黄龙县天然和人工油松林,采集油松根际与非根际土壤,测定非根际土壤化学特性,分离纯化根际土壤解磷(有机磷和无机磷)细菌,通过DNA基因测序鉴定解磷细菌,并测定解磷细菌的解磷能力。结果表明:天然油松林非根际土壤中全碳(TC)、全氮(TN)含量以及C/N、N/P极显著高于人工油松林。2种油松根际土壤中共鉴定出20属65种解磷细菌,其中以芽孢杆菌属、链霉菌属和假单胞菌属为优势菌群;天然油松林根际解磷细菌多样性、丰富度和均匀度指数均高于人工油松林,而优势度指数低于人工油松林。链霉菌属与非根际土壤TC、TN和C/N、N/P呈正相关,而芽孢杆菌属和假单胞菌属与非根际土壤硝态氮、铵态氮、有效磷及全磷含量呈正相关。2种油松林根际土壤不同解磷细菌的解磷能力存在差异,其中天然和人工油松林根际共有的解磷细菌为假单胞菌Pseudomonas sp.34-5,其对磷酸钙的解磷能力最高,为11.40μg·mL^(-1);天然油松林根际独有的解磷细菌蕈状芽胞杆菌BF1-5对卵磷脂的解磷能力最高,为4.58μg·mL^(-1)。该林区2种油松林根际解磷细菌菌群结构存在显著差异。与人工油松林相比,天然油松林根际土壤解磷细菌群落多样性更丰富且分布更均匀,解磷能力普遍高于人工林。To investigate the interaction between Pinus tabuliformis and root microorganisms and its effects on the stability of P.tabuliformis forests,we collected rhizosphere and non-rhizosphere soil from natural and planted P.tabuliformis forests in Huanglong County of Shaanxi Province.The non-rhizosphere soil was used to analyze chemical properties,while the rhizosphere soil was used to isolate and purify phosphorus-solubilizing(organic and inorganic phosphorus)bacteria.We mea-sured the phosphate-solubilizing ability and identified those bacteria using DNA genes sequencing.The results showed that soil total carbon concentration(TC),total nitrogen concentration(TN),carbon:nitrogen(C/N),and nitrogen:phosphorus(N/P)were significantly higher in natural forest than those in the plantation.A total of 20 genera and 65 species of phosphate-solubilizing bacteria were identified in those two forests,with Bacillus,Streptomyces and Pseudomonas as the dominant group.The diversity,richness,and evenness of phosphate-solubilizing bacteria in the natural forest were higher than that in the planted forest,but dominance was lower.Streptomyces was positively correlated with soil TC,TN,C/N and N/P ratios,while Bacillus and Pseudomonas were positively correlated with soil nitrate(NO3-),ammonium(NH4+),available phosphorus(AP),and total phosphorus(TP).The solubilizing ability of phosphate-solubilizing bacteria was different between two forest types,indicating that Pseudomonas sp.34-5 shared in two forests had the strongest phosphate-solubilizing ability for calcium phosphate with 11.40μg·mL^(-1) and Bacillus mycoides BF1-5 exclusive to natural forest had the strongest phosphate-solubilizing ability for lecithin with 4.58μg·mL^(-1).The composition and structure of phosphorus-solubilizing bacterial community were different in two forest types,with higher diversity,richness and phosphate-solubilizing ability in natural forest than that in plantation.

关 键 词：黄土高原 油松林 解磷细菌 解磷能力 

分 类 号：S714.3[农业科学—林学]