A highly diverse fungal community associated with leaves of the mangrove plant Acanthus ilicifolius var. xiamenensis revealed by isolation and metabarcoding analyses

Abstract

A high diversity of culturable foliar endophytic fungi is known from various mangrove plants, and the core taxa include species from Colletotrichum, Pestalotiopsis, Phoma, Phomopsis, Sporomiella, among others. Since a small fraction of fungi is able to grow in culture, this study investigated the diversity of fungi associated with leaves of Acanthus ilicifolius var. xiamenensis using both isolation and metabarcoding approaches. A total of 203 isolates were cultured from surface-sterilized leaves, representing 47 different fungal species: 30 species from the winter samples (104 isolates), and 26 species from the summer samples (99 isolates). Ascomycota was dominant in both types of leaf samples, while Basidiomycota was isolated only from the summer samples. Drechslera dematioidea (10.58%, percentage of occurrence), Colletotrichum sp. 3 (7.69%) and Alternaria sp. (7.69%) were dominant in the winter samples; Fusarium oxysporum (13.13%), Diaporthe endophytica (10.10%) and Colletotrichum sp. 1 (9.09%) in the summer samples. Overall, Corynespora cassiicola (6.90%), F. oxysporum (6.40%) and Guignardia sp. (6.40%) had the highest overall percentage of occurrence. In the metabarcoding analysis, a total of 111 operational taxonomic units (OTUs) were identified from 17 leaf samples: 96 OTUs from the winter and 70 OTUs from the summer samples. Sequences belonging to Ascomycota and Basidiomycota were detected in both samples but the former phylum was dominant over the latter. Based on read abundance, taxa having the highest percentage of occurrence included Alternaria sp. (3.46%), Cladosporium delicatulum (2.56%) and Pyrenochaetopsis leptospora (1.41%) in the winter leaves, and Aureobasidium sp. (10.72%), Cladosporium sp. (7.90%), C. delicatulum (3.45%) and Hortaea werneckii (3.21%) in the summer leaves. These latter four species also had the highest overall percentage of occurrence. Combining the results from both methods, a high diversity of fungi (at least 110 species) was found associated with leaves of A. ilicifolius var. xiamenensis. Many of the fungi identified were plant pathogens and may eventually cause diseases in the host.

Analysis of Endophyte Diversity of Rheum palmatum from Different Production Areas in Gansu Province of China and the Association with Secondary Metabolite

“…The rarefaction curve can reflect the variation of species diversity and the richness of samples with the sequencing amount [ 26 , 27 ]. With the increase in the amount of sequencing effort, the rarefaction curves of the samples based on the number of species observed became stable, which indicated that the amount of sequencing data was gradually becoming reasonable ( Figure 2 ).…”

Mangrove-Associated Fungal Communities Are Differentiated by Geographic Location and Host Structure

“…The first published reports of mangrove-associated fungi were made by Cribb and Cribb (1955) who recorded fungi on the roots of mangroves, and further work by Kohlmeyer (1969) documented visible fungi on numerous mangrove species in the tropics. More recent work on mangrove-associated fungi has on the whole been limited to descriptions of new species or fungal-derived natural products (Ancheeva et al, 2018; Kumar et al, 2019), and those that use molecular techniques to examine fungal communities tend to focus on solitary structures (e.g., leaves) rather than the whole plant and the surrounding environment it grows in (Chi et al, 2019; Yao et al, 2019).…”

Effects of Cropping Practice on Bupleurum Chinense Rhizosphere Microbial Community

“…These rhizosphere microorganisms played an important role in plant growth and the inhibition of pathogenic microorganisms [33][34][35][36][37][38]. In contrast, some potentially pathogenic microorganisms, such as Cercophora [39], Alternaria, Paraphoma, Cladosporium [40], Monographella [41], Hydropisphaera [42], and Colletotrichum were signi cantly ampli ed. For example, Alternaria and Paraphoma can cause root rot of B. chinense [43][44], and Colletotrichum can infect leaves to produce disease spots [45].…”