摘要
连栽导致土壤退化是制约杉木初级生产力实现的重要障碍因素,而土壤对病原菌的抑制能力决定着植物能否有效抵御病原菌侵害,是人工林土壤地力状况的重要表现。以一代、二代、三代杉木人工林和天然次生林为对象,采用平板隔空、直接对峙的方法,分析了不同代际杉木林土壤细菌群落对尖孢镰刀菌和立枯丝核菌的抑制能力。进一步利用高通量测序技术,研究了杉木林土壤细菌群落影响土壤抑病能力的生态过程。结果表明:土壤磷元素随连栽呈显著积累趋势,而土壤pH和有机质(SOM)等含量随连栽代数的增加而下降,但这些下降指标在三代杉木林与天然林土壤间无显著差异。而杉木连栽导致土壤对病原菌的抑制能力逐代降低,天然林土壤较杉木人工林对病原菌具有显著的高抑制能力。同时杉木连栽显著改变了土壤细菌群落组成,而对群落整体α-多样性影响较小,说明土壤中一些关键类群对杉木连栽响应的敏感性高于整体细菌群落的变化。进一步利用随机森林模型预测与回归分析,揭示了杉木连栽引起的土壤一些关键细菌类群丰度的降低是土壤抑病能力下降的重要原因,这些类群主要受土壤pH、SOM、TP等土壤理化因子的调控。由此,杉木长期连栽会引起土壤微环境失衡,致使土壤抑制病原菌能力下降,从而增加病原菌危害杉木林健康,不利于人工林生产力的提升和可持续经营。
Soil degradation caused by successive planting is an important obstacle for the primary productivity of Chinese fir.However,the inhibitory effect of soil on pathogens determines whether plants can effectively resist the invasion of pathogens,which is an important performance of soil health in plantation.In our study,the first generation,the second generation,the third generation Chinese fir plantation and the natural secondary forest soil were selected,and the inhibition of soil bacterial communities from different generations on Fusarium oxysporum and Rhizoctonia solani was analyzed using invert and antagonism assays.The ecological process of soil bacterial community involving in pathogens suppression was studied by high-throughput sequencing.The results indicated that soil phosphorus showed a significant accumulation,while soil pH and soil organic matter(SOM)decreased with the increase of successive planting generations.However,the declined indicators were not significantly different between the third generation forest and natural forest.The successive planting of Chinese fir plantation significantly decreased the inhibitory effect of soil microbial community on pathogens,while the effect of natural secondary forest was significantly higher compared with plantations.The successive planting of Chinese fir significantly changed the composition of soil bacterial community,but no effect onα-diversity of the community,indicating high sensitivity of some key microbiota to successive planting.Random forest model further revealed that the lower abundance of some key microbes caused by Chinese fir successive planting was the main reason for the decline of soil pathogens suppression,and these microbes were mainly regulated by soil pH,SOM and total phosphorus(TP).Therefore,the long-term successive planting of Chinese fir would lead to the imbalance of soil microenvironment,and the reduced ability to inhibit pathogens,which is not conducive to improving productivity and sustainable management of plantations.
作者
余李
廖杨文科
自海云
潘畅
周梦田
曹超阳
李孝刚
YU Li;LIAO Yangwenke;ZI Haiyun;PAN Chang;ZHOU Mengtian;CAO Chaoyang;LI Xiaogang(College of Biology and the Environment,Nanjing Forestry University,Nanjing 210037,China;Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,China)
出处
《生态学报》
CAS
CSCD
北大核心
2023年第12期5038-5049,共12页
Acta Ecologica Sinica
基金
国家自然科学基金项目(32122056,42011045)
江苏省杰出青年基金项目(BK20190040)
江苏省农业科技自主创新资金项目(SCX213717)。
关键词
杉木人工林
代际
土壤细菌群落
土壤抑病
土壤退化
Chinese fir plantation
generations
soil bacterial community
soil pathogen suppression
soil degradation
