Mudflat reclamation causes change in the composition of fungal communities under long-term rice cultivation

Fungi play a critical role in farmland ecosystems, especially in improving soil fertility; however, little is known about the changes in fungal communities caused by mudflat reclamation under rice cultivation. In this study, mudflats located in Yancheng, China, which were divided into nine plots with 0, 11, and 20 years of successive rice cultivation histories, were sampled to determine the fungal community composition by using Illumina MiSeq sequencing. Results show that the Shannon diversity of the fungal communities did not change significantly but the species richness increased under mudflat reclamation with long-term rice cultivation. Ascomycota was the dominant phylum throughout the reclaimed mudflats samples, while Sordariomycetes was the dominant class. Fungal functional prediction found that the relative abundance of saprotrophs gradually increased with mudflat reclamation and mainly belonged to Ascomycota after 20 years of successive reclamation. Redundancy analysis showed that electrical conductivity, organic matter, and total nitrogen were the main factors affecting the composition and ecological function of the fungal community during mudflat reclamation. In short, a fungal community dominated by Ascomycota was established during mudflat reclamation under rice cultivation, which is more conducive to promoting soil fertility because of the higher proportion of saprotrophic fungi in Ascomycota.