夏季庐山常绿阔叶林4种常见植物根际AM真菌分布特征

为了探索夏季庐山常绿阔叶林土壤丛枝菌根真菌（Arbuscular mycorrhizal fungi,AM真菌）资源分布特征,推动其地下AM真菌资源的开发利用。研究基于孢子形态学分类方法对夏季庐山典型常绿阔叶林中4种常见植物（老鼠矢Symplocos stellaris、檵木Loropetalum chinense、连蕊茶Camellia fraterna、山胡椒Lindera glauca）根际土壤AM真菌群落的分布特征进行调查。结果表明：共分离、鉴定出44个AM真菌物种,其中包括4个优势种AM真菌、5个广布种AM真菌、12个常见种AM真菌与23个稀有种AM真菌。（1）不同植物根系侵染率之间存在显著差异,同时根系侵染率与优势种和广布种AM真菌的孢子密度和物种丰富度均呈正相关,与常见种和稀有种AM真菌的孢子密度和物种丰富度则呈负相关,但均不显著;（2）不同植物根际总AM真菌孢子密度不存在显著差异,但AM真菌物种丰富度存在显著差异;此外,不同植物根际只有常见种AM真菌的孢子密度不存在显著差异,也只有广布种和稀有种AM真菌的物种丰富度不存在显著差异;（3）不同优势度AM真菌的孢子密度之间和物种丰富之间均存在负相关,但只有优势种AM真菌的孢子密度与常见种和稀有种AM真菌的孢子密度存在显著负相关;（4）AM真菌分布受土壤养分（全氮、全磷、全钾、氨态氮、硝态氮）、pH和水分影响较小,但受土壤氮影响相对较大;不同优势度AM真菌受土壤养分、pH和水分影响程度不同,影响程度从大到小依次为稀有种AM真菌、常见种AM真菌、广布种AM真菌和优势种AM真菌。在夏季庐山常绿阔叶林中,常见植物与AM真菌的共生模式可能是以优势种AM真菌和广布种AM真菌共生为主,以常见种AM真菌和稀有种AM真菌补充共生的共生模式。在该共生模式下,植物根际AM真菌资源较为丰富且分布不均;AM真菌与植物共生程度由不同优势度AM真菌共同决定;不同优势度AM真菌之间相互影响较弱;AM真菌受土壤养分（全氮、氨态氮、硝态氮、全磷、全钾）、pH和水分影响较小,但不同优势度AM真菌受土壤养分、pH和水分影响程度不同。

Distribution Characteristics of Rhizosphere AM Fungi of Four Common Plants of Evergreen Broad-leaved Forests of Lushan Mountain in Summer

To explore the distribution characteristics of soil arbuscular mycorrhizal fungi (AM fungi), and promote the development and utilization of underground AM fungi resources, the distribution characteristics of rhizosphere AM fungal communities of four common plants (Symplocos stellaris, Loropetalum chinense, Camellia fraternal and Lindera glauca) of typical evergreen broad-leaved forests of Lushan Mountain in summer were investigated according to the method of spore morphology classification. The results showed that 44 AM fungal species (4 dominant species, 5 most common species, 12 common species, and 23 rare species) were isolated and identified. (1) There were significant differences in root colonization rate among different plants. The root colonization rate was positively correlated with the spore density and species richness of AM fungi in dominant and most common species, while negatively correlated with them in common and rare species, and the correlations were both not significant. (2) There was no significant difference in total spore density of AM fungi, while significant differences were found in species richness of AM fungi among different plants. In addition, there was no significant difference in the spore density of AM fungi of common species and the species richness of AM fungi of most common and rare species among different plants. (3) A negative correlation between spore density and species richness was found in AM fungi with different dominance. There was only a significantly negative correlation between the spore density of dominant species AM fungi and the spore density of common and rare species AM fungi. (4) Soil nutrients (total nitrogen, total phosphorus, total potassium, ammoniacal nitrogen, and nitrate nitrogen), pH and soil water contributed less to the distribution of AM fungi. However, the distribution of AM fungi was mainly affected by soil nitrogen. AM fungi of various dominant degrees were affected differently by soil nutrients, pH and water (rare species > common species > most common species > dominant species). The symbiosis pattern between common plants and AM fungi might be dominated by dominant and most common species, and supplemented by common and rare species of evergreen broad-leaved forests of Lushan Mountain in summer. According to the symbiosis pattern, AM fungi resources of plant rhizosphere were abundant and unevenly distributed; the degree of symbiosis between AM fungi and plants was determined by the different dominance of AM fungi; the interaction between AM fungi with different dominance was small; AM fungi were less affected by soil nutrients (total nitrogen, ammonia nitrogen, nitrate nitrogen, total phosphorus, and total potassium), pH and water, however, AM fungi of various dominant degrees were affected differently by soil nutrients, pH value and water.