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Termites are serious pests in agriculture and forestry, causing significant economic losses to property and the construction industry. However, only a few entomopathogenic fungi attack termites that are dominant members of most terrestrial biomes. This study contributes to the taxonomic knowledge of entomopathogenic fungi with the description of a new pathogen on termites collected from the Pu Luong Nature Reserve in Vietnam. The new termite pathogen, Ophiocordyceps puluongensis, is introduced on the basis of morphological and multigene phylogenetic evidence. Based on the combined dataset of five genes including the nuclear ribosomal small and large subunits (nrSSU and nrLSU), the elongation factor 1α (tef-1α), and the largest and the second largest subunits of RNA polymerase II (rpb1 and rpb2), phylogenetic analyses were performed by Maximum Likelihood and Bayesian inference methods to determine the phylogenetic position of O. puluongensis. Three samples of O. puluongensis are clustered in the Hirsutella thompsonii subclade of Hirsutella lineages in Ophiocordyceps, and clustered together with O. asiatica to form a separate clade from other Ophiocordyceps species. Morphologically, O. puluongensis differs from O. asiatica by its smaller and shorter perithecia, asci and ascospores, pink to reddish-orange stipes of stromata, as well as smaller fusiform or citriform conidia. The distinctiveness of this termite pathogen is strongly supported by both molecular phylogeny and morphology. The entomopathogenic fungus O. puluongensis could have the potential to be used as bioinsecticides to control termites.
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Hypocreales , Isópteros , Animales , Teorema de Bayes , Hypocreales/genética , Filogenia , Esporas Fúngicas/genética , VietnamRESUMEN
Akanthomyces, a group of fungi with rich morphological and ecological diversity in Cordycipitaceae (Ascomycota, Hypocreales), has a wide distribution amongst diverse habitats. By surveying arthropod-pathogenic fungi in China and Southeast Asia over the last six years, nine Akanthomyces spp. were found and identified. Five of these were shown to represent four known species and an undetermined species of Akanthomyces. Four of these were new species and they were named A.kunmingensis and A.subaraneicola from China, A.laosensis from Laos and A.pseudonoctuidarum from Thailand. The new species were described and illustrated according to the morphological characteristics and molecular data. Akanthomycesaraneogenus, which was isolated from spiders from different regions in China, Thailand and Vietnam, was described as a newly-recorded species from Thailand and Vietnam. The phylogenetic positions of the nine species were evaluated, based on phylogenetic inferences according to five loci, namely, ITS, nrLSU, TEF, RPB1 and RPB2. In this study, we reviewed the research progress achieved for Akanthomyces regarding its taxonomy, species diversity, geographic distribution and major host/substrate associations. The morphological characteristics of 35 species in Akanthomyces, including four novel species and 31 known taxa, were also compared.
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Samsoniella is a ubiquitous genus of cosmopolitan arthropod-pathogenic fungi in the family Cordycipitaceae. The fungi have economic, medicinal, and ecological importance. Prior taxonomic studies of these fungi relied predominantly on phylogenetic inferences from five loci, namely, the nuclear ribosomal small and large subunits (nr SSU and nr LSU), the 3' portion of translation elongation factor 1 alpha (3P_TEF), and RNA polymerase II subunits 1 and 2 (RPB1 and RPB2). Despite many new species being described, not all of the recognized species inside this group formed well-supported clades. Thus, the search for new markers appropriate for molecular phylogenetic analysis of Samsoniella remains a challenging problem. In our study, we selected the internal transcribed spacer regions of the rDNA (ITS rDNA) and seven gene regions, namely, 3P_TEF, the 5' portion of translation elongation factor 1 alpha (5P_TEF), RPB1, RPB2, γ-actin (ACT), ß-tubulin (TUB), and a gene encoding a minichromosome maintenance protein (MCM7), as candidate markers for species identification. Genetic divergence comparisons showed that the ITS, RPB2, ACT, and TUB sequences provided little valuable information with which to separate Samsoniella spp. In contrast, sequence data for 3P_TEF, 5P_TEF, RPB1, and MCM7 provided good resolution of Samsoniella species. The phylogenetic tree inferred from combined data (5P_TEF + 3P_TEF + RPB1 + MCM7) showed well-supported clades for Samsoniella and allowed for the delimitation of 26 species in this genus. The other two species (S.formicae and S.lepidopterorum) were not evaluated, as they had abundant missing data.
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Introduction: Clonostachys, a genus with rich morphological and ecological diversity in Bionectriaceae, has a wide distribution among diverse habitats. Methods and Results: In the present study, a phylogenetic framework is reconstructed for the family Bionectriaceae focusing on Clonostachys through increased taxon-sampling using the nrLSU sequence. Through surveying Clonostachys in China, Vietnam, and Thailand over the past 3 years, seven Clonostachys spp. were found and identified. Two new species, C. chuyangsinensis and C. kunmingensis, are described and illustrated based on morphological characteristics and molecular data. The phylogenetic positions of the seven species were evaluated based on four genomic loci (ITS, nrLSU, TUB2, and TEF1). Discussion: Moreover, the genetic divergence comparisons of Clonostachys species for three markers (ITS, TUB2, and TEF1) are also provided. The results indicated that the TEF1 sequence data provided the best resolution for distinguishing species of Clonostachys, followed by sequence data for the TUB2 and ITS regions.
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The Cordyceps militaris complex, which is a special group in the genus Cordyceps, is rich in species diversity and is widely distributed in nature. Throughout the investigations of arthropod-pathogenic fungi in the national reserves and in Vietnam parks, collections of C. militaris attacking lepidopteran pupae or larvae were located in the soil and on the leaf litter. The phylogenetic analyses of the combined nrSSU, nrLSU, TEF, RPB1, and RPB2 sequence data indicated that the fungal materials collected in Vietnam belonged to C. militaris and two hidden species in the C. militaris complex. The phylogenetic analyses and morphological comparisons presented here strongly supported the descriptions of C. polystromata and C. sapaensis as new taxa as well as C. militaris as a known species. The morphological characteristics of 11 species in the C. militaris complex, which included two novel species and nine known taxa, were also compared.
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Samsoniella is a very important fungal resource, with some species in the genus having great medical, economic and ecological value. This study reports five new species of Samsoniella from Yunnan Province and Guizhou Province in Southwestern China and Dole Province in Vietnam, providing morphological descriptions, illustrations, phylogenetic placements, associated hosts and comparisons with allied taxa. Based on morphological observations and phylogenetic analyses of combined nrSSU, nrLSU, tef-1α, rpb1 and rpb2 sequence data, it was determined that these five new species were located in the clade of Samsoniella and different from other species of Samsoniella. The five novel species had morphologies similar to those of other species in the genus, with bright orange cylindrical to clavate stromata (gregarious). The fertile part lateral sides usually had a longitudinal ditch without producing perithecia, and superficial perithecia. The phialides had a swollen basal portion, tapering abruptly into a narrow neck and oval or fusiform one-celled conidia, often in chains. The morphological characteristics of 23 species in Samsoniella, including five novel species and 18 known taxa, were also compared in the present study.