Long-term Effects of Mixed Management on Arbuscular Mycorrhizal Fungal Community of Root and Soil in Juglans mandshurica Plantation

Abstract

Background: The establishment of mixed plantations is an effective way to improve soil fertility and increase forest productivity. Arbuscular mycorrhiza (AM) fungi are a kind of obligated symbiotic fungi, which can promote plants absorption of mineral nutrients and regulate intraspecific and interspecific competition. However, the effects of mixture on the community structure and abundance of AM fungi are still unclear. The Illumina MiSeq sequencing technique was used to determine the AM fungal community in the roots and soils of pure and mixed plantations (Juglans mandshurica × Larix gmelinii). The objective is to compare the response from root and rhizosphere soil AM fungal communities of Juglans mandshurica to long-term mixed plantation management. Results: Glomus and Paraglomus were the dominant genus in root samples, which accounted for more than 80% of the sequences. Compared with the pure plantation, the relative abundance of Glomus was higher in mixed plantation. Glomus, Diversispora and Paraglomus accounted for more than 85% of the sequences in soil samples. The relative abundance of Diversispora and Unclassified_c__Glomeromycetes were higher and lower in pure plantation, respectively. Samples of the Root_P (roots in pure plantation) had the highest number of unique OTUs (Operational Taxonomic Units), which were mainly composed of sequences belonging to unclassified_c__Glomeromycetes, Paraglomus, Glomus and Acaulospora. The amount of unique OTU detected in soil in pure and mixed plantation was relatively close. In the same types of sample (whether root or soil), the forest type did not have significant effect on AM fungal diversity, but the Sobs, Shannon, Chao1 and Ace indices of AM fungi in the roots were significantly higher than those in the soil. Conclusions: The mixed forest management had little effect on the AM fungal community in the root of Juglans mandshurica, but significantly changed the community composition of the soil AM fungi rather than diversity.