Morpho-Phylogenetic Evidence Reveals Novel Pleosporalean Taxa from Sichuan Province, China

New Insights into Tetraplosphaeriaceae Based on Taxonomic Investigations of Bambusicolous Fungi and Freshwater Fungi

Species within Tetraplosphaeriaceae have been frequently documented in recent years with the extensive investigations of microfungi along a latitudinal gradient from north to south in the Asian/Australian region. Both bamboo substrates and freshwater habitats serve as extensive reservoirs, hosting a rich diversity of fungi that exhibit broad geographical distributions. The most common fungi in these two environments are generally distributed in distinct families. However, our statistics have revealed an intriguingly distinct preference of Tetraplosphaeriaceae species for inhabiting both bamboo substrates and freshwater habitats. The genera Pseudotetraploa (100%) and Triplosphaeria (100%) exhibit a strong preference, followed by Shrungabeeja (71%) and Quadricrura (67%). Our taxonomic and phylogenetic study of microfungi in southern China have identified four additional novel species, viz., Aquatisphaeria bambusae sp. nov., Pseudotetraploa phyllostachydis sp. nov., Pseudotetraploa yangjiangensis sp. nov., and Tetraploa submersa sp. nov. from bamboo substrates and freshwater habitats. In addition, Aquatisphaeria thailandica has previously been documented from freshwater habitats in Thailand; however, we have once again isolated this species from decaying bamboo substrates in Guangdong, China. The new findings substantiate our hypothesis that the preference of Tetraplosphaeriaceae species for colonizing bamboo substrates and freshwater habitats will be more evident through more extensive investigations conducted in such environments.

Exploring ascomycete diversity in Yunnan II: Introducing three novel species in the suborder Massarineae (Dothideomycetes, Pleosporales) from fern and grasses

This article presents the results of an ongoing inventory of Ascomycota in Yunnan, China, carried out as part of the research project series "Exploring ascomycete diversity in Yunnan". From over 100 samples collected from diverse host substrates, microfungi have been isolated, identified and are currently being documented. The primary objective of this research is to promote the discovery of novel taxa and explore the ascomycete diversity in the region, utilising a morphology-phylogeny approach. This article represents the second series of species descriptions for the project and introduces three undocumented species found in the families Bambusicolaceae, Dictyosporiaceae and Periconiaceae, belonging to the suborder Massarineae (Pleosporales, Dothideomycetes). These novel taxa exhibit typical morphological characteristics of Bambusicola, Periconia and Trichobotrys, leading to their designation as Bambusicolahongheensis, Periconiakunmingensis and Trichobotryssinensis. Comprehensive multigene phylogenetic analyses were conducted to validate the novelty of these species. The results revealed well-defined clades that are clearly distinct from other related species, providing robust support for their placement within their respective families. Notably, this study unveils the phylogenetic affinity of Trichobotrys within Dictyosporiaceae for the first time. Additionally, the synanamorphism for the genus Trichobotrys is also reported for the first time. Detailed descriptions, illustrations and updated phylogenies of the novel species are provided, and thus presenting a valuable resource for researchers and mycologists interested in the diversity of ascomycetes in Yunnan. By enhancing our understanding of the Ascomycota diversity in this region, this research contributes to the broader field of fungal taxonomy and their phylogenetic understanding.

Seasonal dynamics of phyllosphere epiphytic microbial communities of medicinal plants in farmland environment

Introduction

The phyllosphere of plants is inhabited by various microorganisms, which play a crucial role in plant physiological metabolism. Currently, there is limited research on the dynamic effects of species and seasons on plant phyllosphere microbial community diversity and microbial interactions.

Methods

In this study, high-throughput sequencing technology was used to sequence the leaf surface parasitic microorganisms of five medicinal plants (Bupleurum chinense, Atractylodes lancea, Salvia miltiorrhiza, Astragalus membranaceus, and Lonicera japonica).

Results

The results showed that bacteria and fungi clustered into 3,898 and 1,572 operational taxonomic units (OTUs), respectively. Compared to host species, seasons had a more significant impact on the a diversity of bacteria and fungi. The heterogeneity of phyllosphere microbial communities was greater in winter compared to summer. Key species analysis at the OTU level and Spearman correlation analysis demonstrated significant preferences in microbial interactions under plant and seasonal backgrounds. The network connections between bacterial and fungal communities significantly increased during seasonal transitions compared to connections with plants.

Discussion

This study enhances our understanding of the composition and ecological roles of plant-associated microbial communities in small-scale agricultural environments. Additionally, it provides valuable insights for assessing the biodiversity of medicinal plants.

Morphophylogenetic evidence reveals four new fungal species within Tetraplosphaeriaceae (Pleosporales, Ascomycota) from tropical and subtropical forest in China

Tetraplosphaeriaceae (Pleosporales, Ascomycota) is a family with many saprobes recorded from various hosts, especially bamboo and grasses. During a taxonomic investigation of microfungi in tropical and subtropical forest regions of Guizhou, Hainan and Yunnan provinces, China, several plant samples were collected and examined for fungi. Four newly discovered species are described based on morphology and evolutionary relationships with their allies inferred from phylogenetic analyses derived from a combined dataset of LSU, ITS, SSU, and tub2 DNA sequence data. Detailed illustrations, descriptions and taxonomic notes are provided for each species. The four new species of Tetraplosphaeriaceae reported herein are Polyplosphaeriaguizhouensis, Polyplosphaeriahainanensis, Pseudotetraploayunnanensis, and Tetraploahainanensis. A checklist of Tetraplosphaeriaceae species with available details on their ecology is also provided.

Diversity of Fungal Communities on Diseased and Healthy Cinnamomum burmannii Fruits and Antibacterial Activity of Secondary Metabolites

The composition and structure of fungal communities on healthy and diseased fruits of Cinnamomum burmannii (Nees and Nees) Blume were characterized, with evaluation of the antibacterial activity of secondary metabolites from culturable fungi following the first identification of secondary metabolites in the fungus Medicopsis romeroi (Esf-14; GenBank accession number OK242756). These results are significant for understanding the functional variation in bioactivity in fungal communities and developing a broader range of bioactive resources. High-throughput sequencing results indicated that the fungal community in diseased fruit differed from that in healthy fruit at the phylum, class, order, or genus level, with significant differences in the species and relative abundance of the dominant flora. A total of 49 (healthy fruit) and 122 (diseased fruit) artificially cultivable endophytic fungi were isolated, and 41 different strains (11 from healthy fruit and 30 from diseased fruit) were successfully identified by morphological and molecular biological analyses, which were classified into 8 groups and 23 genera by phylogenetic tree analysis, with Pleosporales, Glomerellales, and Hypocreales being the dominant groups at the order level and Colletotrichum being the dominant group at the genus level. The results of the antibacterial assay demonstrated that the secondary metabolites of all strains had different degrees of antibacterial activity, while the secondary metabolites of endophytic fungi from diseased fruit were generally stronger than those of fungi from healthy fruit, with the active secondary metabolites dominated by small and moderately polar compounds. Combined analysis of fungal communities, phylogenetic tree analysis, and bioactivity analysis of culturable strains revealed strong antibacterial activity of both upregulated and downregulated flora in diseased fruit. Five compounds, including two new (5,6-dimethoxy-[1',1:4,1″-terphenyl]-2-ol [compound 1] and 5-(methoxycarbonyl)-2-methylbenzo[d][1,3]dioxole-2-carboxylic acid [compound 2]) and three known compounds (3,7-dihydroxy-1,9-dimethyldibenzofuran [compound 3], methyl 3-hydroxybenzoate [compound 4], and uracil [compound 5]), were isolated and identified for the first time from the endophytic fungus Medicopsis romeroi. In general, the diversity of fungal communities on diseased fruit was lower than that on healthy fruits, while the antibacterial activity of artificially cultured endophytic fungi on diseased fruits was generally stronger than that on healthy fruits, suggesting excellent promise for the development of secondary metabolites from active strains on diseased fruit as antibacterial agents. IMPORTANCE Powdery fruit disease is a notorious disease of Cinnamomum burmannii that causes severe loss in fruit production. Studies on the function of endophytic fungal communities in healthy plant tissues are not new, while little is known about the functional changes of fungal communities in disease-causing plant tissues. Our results demonstrate that fungal communities in diseased fruits differ from those in healthy fruits at the level of phylum, class, order, or genus, with significant differences in the species and relative abundance of dominant groups. Endophytic fungi in diseased fruits appeared to produce secondary metabolites with stronger antibacterial properties, although the community diversity was not as varied as that in healthy fruits. In addition, secondary metabolites of the Medicopsis romeroi strain from diseased fruits were identified for the first time. These results have important implications for understanding the functional variation of bioactivity in fungal communities and for developing a broader resource of bioactivity.

Additions to Bambusicolous Fungi of Savoryellaceae from Southwest China

Asexual and sexual morphs of saprobic bambusicolous fungi were collected from freshwater and terrestrial habitats in Sichuan Province, China. Taxonomic identification of these fungi was carried out on the basis of morphological comparison, culture characteristics, and molecular phylogeny. Multi-gene phylogeny based on combined SSU, ITS, LSU, rpb2, and tef1α sequence data was performed to determine their phylogenetic placement, and the result showed that these fungi belong to Savoryellaceae. Morphologically, four asexual morphs are similar to Canalisporium and Dematiosporium, while a sexual morph well-fits to Savoryella. Three new species, Canalisporium sichuanense, Dematiosporium bambusicola, and Savoryella bambusicola are identified and described. Two new records, C. dehongense and D. aquaticum, were recovered from the bamboo hosts in terrestrial and freshwater habitats, respectively. In addition, the nomenclatural confusion of C. dehongense and C. thailandense is discussed.