Structural variability and niche differentiation of the rhizosphere and endosphere fungal microbiome of Casuarina equisetifolia at different ages.

Abstract

Casuarina equisetifolia is one of the most important artificially planted protective forests along the coast in southern China for windbreaks, soil erosion, and sand dune stabilization. Self-renewing of C. equisetifolia is very limited, which might be caused by low soil nutrient levels and reduced microbial activity. Use of high-throughput sequencing of the 18S rDNA to investigate the microbial communities from the rhizosphere and root endosphere of C. equisetifolia in young-aged, intermediate-aged, and mature-aged forests. Our results indicate that the diversity of rhizosphere fungal microbiomes in field-grown C. equisetifolia is much lower than that of the endosphere microbiomes. Bioinformatic analysis showed that rhizocompartments produce the strongest differentiation of rhizosphere and endosphere communities. Notably, the distribution of rhizosphere fungi communities was significantly influenced by the environmental factors, not by forest ages. The presented study suggests that the rhizocompartments and environmental factors, rather than forest ages, determine the diversities of fungal community.