本文排版定稿已在中国知网网络首发,如需阅读全文请打开知网首页,并搜索该论文题目即可查看。
混交林形成对油茶根际养分和丛枝菌根真菌多样性的影响
Effects of Mixed Forest Formation on Rhizosphere Nutrients and Arbuscular Mycorrhizal Fungal Diversity of oil Camellia
-
摘要: 以相同环境条件下人工油茶纯林、野生油茶纯林及其与马尾松、杉木混交林的油茶根际土和吸收根为研究对象,分析根际土主要养分含量,分离其中AMF孢子并对其进行形态学鉴定,吸收根测定菌根侵染;利用相关性分析揭示不同林型的土壤理化性质与菌根侵染率、孢子密度、AMF多样性之间的相关性。结果表明:野生油茶与2种针叶树混交后,有效养分(NH4 + 、NO3−、速效钾)含量显著提高;4种林型油茶根系均存在典型的丛枝菌根结构,混交林的菌根侵染率与丛枝丰度显著高于纯林,尤以与杉木混交对菌根形成促进明显;根际AMF孢子密度以野生油茶/马尾松混交林最高。形态鉴定发现AMF 2门2纲6目12科22属86种,混交林的AMF群落多样性及均匀度均高于纯林。土壤速效养分含量与菌根侵染率、孢子密度及多样性指标呈显著正相关,混交林的形成可提升油茶根际有效养分含量和AMF多样性。Abstract: In this study, we examined rhizosphere soil and absorptive roots from oil Camellia plantations, wild oil Camellia pure forests, and their mixed forests with Pinus massoniana and Cunninghamia lanceolata under identical environmental conditions. We analyzed major nutrient contents in the rhizosphere soil, isolated AMF spores for morphological identification, and assessed mycorrhizal colonization in absorptive roots. The results showed that after wild oil Camellia was mixed with the two coniferous species, the contents of available nutrients (NH4 + , NO3−, available potassium) increased significantly. Typical arbuscular mycorrhizal structures were observed in all four types of oil Camellia forests, and both the colonization rate and arbuscule abundance were significantly higher in mixed forests than in pure forests, with the mixed stand involving Cunninghamia lanceolata showing the strongest promotion of mycorrhiza formation. The highest AMF spore density in rhizosphere soil occurred in the wild oil Camellia /P. massoniana mixed forest. Morphological identification revealed 86 AMF species belonging to 2 phyla, 2 classes, 6 orders, 12 families, and 22 genera, and the AMF community diversity and evenness were higher in mixed forests than in pure forests. Correlation analysis indicated significant positive relationships between soil available nutrient contents and mycorrhizal colonization rate, spore density, and diversity indices. Overall, the establishment of mixed forests can improve rhizosphere nutrient availability and AMF diversity in oil Camellia.
下载: