摘要
运用末端限制性片段长度多态性(terminal restriction fragment length polymorphism,T-RFLP)和荧光定量PCR(real-time PCR)法,检测喀斯特灌丛生态系统中不同岩性条件下土壤固氮菌与丛枝菌根(arbuscular mycorrhizal,AM)真菌群落结构与丰度的变化,揭示岩性对灌丛生态系统土壤中固氮菌与AM真菌群落结构与丰度的影响.结果表明不同岩性条件下,土壤固氮菌与AM真菌丰度存在显著差异,其中,固氮菌与AM真菌丰度在石灰岩土壤中最大,白云岩土壤中最小,石灰岩-白云岩夹层土壤介于两者之间;同样,不同岩性土壤中固氮菌与AM真菌群落结构存在显著性差异.土壤Olsen-P、有机碳、黏粒含量与固氮菌丰度存在显著正相关关系,而土壤全氮、黏粒含量与AM真菌丰度存在显著正相关.RDA分析表明,植物均匀度影响固氮菌群落组成结构,而植物均匀度、香农多样性指数及丰富度指数影响AM真菌群落组成结构.以上的研究结果表明:岩性主要是通过影响植物与土壤养分来影响土壤固氮菌与AM真菌群落组成结构及丰度.
Lithology is a key factor when used to restore vegetation in karst degraded ecosystems,and arbuscular mycorrhizal（ AM）fungi and nitrogen-fixing bacteria play an important role in improving plant growth. However,little information is available regarding the effects of lithology on these two groups of microorganisms. To test whether these microbial communities are impacted by lithology,the abundance and composition of soil AM fungal and nitrogen-fixing bacteria communities were determined through terminal restriction fragment length polymorphism（ T-RFLP） and real-time fluorescence-based quantitative PCR（ real-time PCR）. Three types of lithology（ dolomite,limestone and dolomite-limestone） were selected in this study. The diversity,richness,and evenness of plant species were evaluated through field surveys and soil properties were measured. The results showed that the abundances of soil nitrogen-fixing bacteria and arbuscular mycorrhizal fungal communities were significantly influenced by lithology. The abundances of these two groups of microorganisms were the lowest in dolomite soil,inferior to dolomite-limestone soil,while highest in limestone soil. Similarly,the composition of soil nitrogen-fixing bacteria and AM fungi communities varied among lithology. A significant linear correlation was observed among soil organic carbon,available phosphorus,clay content and nitrogen-fixing bacterial abundance（ P 〈 0. 05）,and a significant linear correlation among total nitrogen,clay content and AM fungal abundance（ P 〈0. 05）. Redundancy analysis showed that the composition of nitrogen-fixing bacterial community was closely linked to plant evenness,and the AM fungal community composition was closely linked to plant diversity（ plant evenness,Shannon-wiener and richness）. These results indicated that lithology influenced the abundances and compositions of soil nitrogen-fixing bacteria and arbuscular mycorrhizal（ AM） fungal communities mainly through plant and soil properties.
作者
梁月明
苏以荣
何寻阳
陈香碧
LIANG Yue-ming SU Yi-rong HE Xun-yang CHEN Xiang-bi(Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China Key Laboratory of Karst Dynamics, Ministry of Land and Resources ＆ Guangxi Zhuangzu Autonomy Region, Institute of Karst Geology, Chinese Academy of Geological Sciences,Guilin 541004, China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第3期1253-1261,共9页
Environmental Science
基金
国家重点研发计划项目(2016YFC0502404)
广西自然科学基金项目(2016GXNSFBA380179)
国家自然科学基金项目(41301273
31270551)
岩溶地质研究所基本科研业务费项目(2016004)
中国科学院"西部之光"人才培养计划项目
中国地质大调查项目(121201237000160002)
关键词
喀斯特
灌丛生态系统
岩性
固氮菌
丛枝菌根真菌
群落结构
karst
shrub ecosystem
lithology
nitrogen-fixing bacteria
arbuscular mycorrhizal fungi
community structure
