Studies On Phylogeny Of Polycephalomycetaceae Fam. Nov., With Microbial Diversities Of Polycephalomyces Multiramosus And Its Host

The genus Polycephalomyces reflects rich diversities of morphology and ecology in Hypocreales, and morphological characteristics with the sexual stage and asexual stage are much various in this genus. Species have complicated associations with hosts, excepting for parasitizing insects, with being often hyperparasitic on Elaphomyces, Myxomycetes and other fungi in Hypocreales. It remains an incertae sedis member of Hypocreales as insufficient taxon sampling and unclear understanding. The most extensive taxon sampling was conducted among genus Polycephalomyces and its related families, and molecular phylogeny was investigated using 5-gene (nrSSU, nrLSU, tef-1α, rpb1and rpb2) dataset in the present paper. Its systematic position in Hypocreales was determined, combining morphological and ecological characteristics. The phylogenetic tree of genus Polycephalomyces was built using combined ITS and 5-gene dataset. Combining morphological and ecological characteristics, species and their positions were defined and determined, respectively. Keys to species in this genus were constructed after describing species. Four species with unclear taxonomical status and incorrect taxonomical treatments were reexamined and revised. Based on the Illumina deep high-throughput sequencing technology, the microbial diversities for E. granulatus, P. multiramosus, Tolypocladium ophioglossoides and T. capitatium collected in a plot were comparatively analyzed. Main findings in this study as follows:(1) The most extensive taxon sampling was conducted among genus Polycephalomyces and its related families, and phylogenetic tree was built using 5-gene dataset. The genus presented as a monophyletic group in the order Hypocreales.(2) The phylogenetic tree of genus Polycephalomyces was built using the ITS and 5-gene dataset, thus interspecific phylogenetic ralationships were explicated. Systematic positions of species within this genus were confirmed. The taxonomical statuses from nine new species, four new combinitions, and eight pending species were determined.(3) Multi-gene phylogenetic analysis revealed that genus Polycephalomyces is a monophyletic group in the order Hypocreales, being consistent with its morphology and ecology were distinctly different from its related families. Therefore, a new family Polycephlomycetaceae H. Yu & Y.B. Wang was described. C. pleuricapitata was combined into P. pleuricapitatus, and thus only one genus was existed in Polycephlomycetaceae.(4) All of the known species in this genus were described and noted on the basis of morphological and ecological traits, keys to species in Polycephalomyces were also constructed. The nine new species are P. agaricus H. Yu & Y.B. Wang, P. arbusculus H. Yu & Y.B. Wang, P. capitatus H. Yu & Y.B. Wang, P. cicadae H. Yu & Y.B. Wang, P. daweiensis H. Yu & Y.B. Wang, P. highlandensis H. Yu & Y.B. Wang, P. roseoalbus H. Yu & Y.B. Wang, P. spatulatus H. Yu & Y.B. Wang, P. yunnanensis H. Yu, Y.B. Wang & YD. Dai, respectively. The four new combinations are P. cuncunae (Palfner) H. Yu & Y.B. Wang, P. pleuricapitatus (Kobayasi & Shimizu) H. Yu & Y.B. Wang, P. multiramosus (Teng) H. Yu & Y.B. Wang, P. sessilisus (Kaitsu, Uchiy.& Kinjo) H. Yu & Y.B. Wang, respectively.(5) Using the Illumina deep high-throughput sequencing technology, fungal diversities for E. granulatus, P. multiramosus, T. ophioglossoides and T. capitatium collected in a plot were comparatively analyzed. It was showed that the most dominant fungi of these four species belong to Eurotiales and Hypocreales (Ophiocordycipitaceae) wthin Ascomycota. Intra specific fungal community structures were similar among four taxa. Athough interspecific fungal community structures were also similar, the biomarkers with statistical differences could be found among these species.(6) The bacterial diversities from E. granulatus, P. multiramosus, T. ophioglossoides and T. capitatium were comparatively analyzed. It was revealed that the most dominant bacteria of these four species belong to Proteobacteria, mainly including Rhizobiales, Sphingobacteriales, and Xanthomonadales (Rhizobiaceae accounting for the largest proportion). Intra specific fungal community structures are similar, excepting for specific samples. The three species presented obviously different bacterial communities, the biomarkers with statistical differences could be discovered among E. granulatus, P. multiramosus, T. ophioglossoides and T. capitatium.