Population genomics revealed cryptic species within host-specific zombie-ant fungi (Ophiocordyceps unilateralis)

International audienceThe identification and delimitation of species boundaries are essential for understanding speciation and adaptation processes and for the management of biodiversity as well as development for applications. Ophiocordyceps unilateralis sensu lato is a complex of fungal pathogens parasitizing Formicine ants, inducing zombie behaviors in their hosts. Previous taxonomic works with limited numbers of samples and markers led to the "one ant-one fun-gus" paradigm, resulting in the use of ant species as a proxy for fungal identification. Here, a population genomics study with sampling on three ant species across Thailand supported the existence of host-specific species in O. unilateralis s.l. with no footprints of long term introgression despite occasional host shifts and first-generation hybrids. We further detected genetic clusters within the previously delimited fungal species, with each little footprints of recombination, suggesting high levels of inbreeding. The clusters within each of O. camponoti-leonardi and O. camponoti-saundersi were supported by differentiation throughout the genome, suggesting they may constitute further cryptic species parasitizing the same host, challenging the one ant-one fungus paradigm. These genetic clusters had different geographical ranges, supporting different biogeographic influences between the north/center and the south of Thailand, reinforcing the scenario in which Thailand endured compartmentation during the latest Pleistocene glacial cycles

Comprehensive treatise of Hevansia and three new genera Jenniferia, Parahevansia and Polystromomyces on spiders in Cordycipitaceae from Thailand

Collections of pathogenic fungi found on spiders from Thailand were selected for a detailed taxonomic study. Morphological comparison and phylogenetic analyses of the combined ITS, LSU, tef1, rpb1 and rpb2 sequence data indicated that these specimens formed new independent lineages within the Cordycipitaceae, containing two new genera occurring on spiders, i.e. Jenniferia gen. nov. and Polystromomyces gen. nov. Two new species in Jenniferia, J. griseocinerea sp. nov. and J. thomisidarum sp. nov., are described. Two strains, NHJ 03510 and BCC 2191, initially named as Akanthomyces cinereus (Hevansia cinerea), were shown to be part of Jenniferia. By including sequences of putative Hevansia species from GenBank, we also revealed Parahevansia as a new genus with the ex-type strain NHJ 666.01 of Pa. koratensis, accommodating specimens previously named as Akanthomyces koratensis (Hevansia koratensis). One species of Polystromomyces, Po. araneae sp. nov., is described. We established an asexual-sexual morph connection for Hevansia novoguineensis (Cordycipitaceae) with ex-type CBS 610.80 and proposed a new species, H. minuta sp. nov. Based on characteristics of the sexual morph, Hevansia and Polystromomyces share phenotypic traits by producing stipitate ascoma with fertile terminal heads; however, they differ in the shape and colour of the stipes. Meanwhile, Jenniferia produces non-stipitate ascoma with aggregated superficial perithecia forming a cushion. A new morphology of ascospores in Jenniferia is described, illustrated and compared with other species in Cordycipitaceae

Diversity of Akanthomyces on moths (Lepidoptera) in Thailand

Akanthomyces is a genus of invertebrate-pathogenic fungi from the family Cordycipitaceae (Ascomycota, Hypocreales). Its species occurs on two different types of hosts, spiders and insects, and in the latter case specifically Lepidoptera adults. Three new species of Akanthomyces, A. noctuidarum, A. pyralidarum, and A. tortricidarum occurring on adult moths from Thailand are proposed based on the differences of their morphological characteristics and molecular data. Phylogenetic analyses using a combined dataset, including the internal transcribed spacer regions, the large subunit of the ribosomal DNA, translation elongation factor 1-α, the largest subunit of RNA polymerase II, and the second largest subunit of RNA polymerase II, support the delimitation of these new species in Akanthomyces

Is Hyperdermium Congeneric with Ascopolyporus? Phylogenetic Relationships of Ascopolyporus spp. (Cordycipitaceae, Hypocreales) and a New Genus Neohyperdermium on Scale Insects in Thailand

During surveys of insect pathogenic fungi (IPF) in Thailand, fungi associated with scale insects and plants were found to represent five new species of the genus Ascopolyporus in Cordycipitaceae. Their macroscopic features resembled both Hyperdermium and Ascopolyporus. Morphological comparisons with the type and known Ascopolyporus and Hyperdermium species and phylogenetic evidence from a multigene dataset support the appointment of a new species of Ascopolyporus. Moreover, the data also revealed that the type species of Hyperdermium, H. caulium, is nested within Ascopolyporus, suggesting that Hyperdermium is congeneric with Ascopolyporus. The specimens investigated here differ from other Ascopolyporus species by phenotypic characters including size and color of stromata. Phylogenetic analyses of combined LSU, TEF1, RPB1 and RPB2 sequences strongly support the notion that these strains are distinct from known species of Ascopolyporus, and are proposed as Ascopolyporus albus, A. galloides, A. griseoperitheciatus, A. khaoyaiensis and A. purpuratus. Neohyperdermium gen. nov. is introduced for other species originally assigned to Hyperdermium and Cordyceps occurring on scale insects and host plants as epiphytes, accommodating two new combinations of Hyperdermium pulvinatum and Cordyceps piperis

Ophiocordyceps flavida sp. nov. (Ophiocordycipitaceae), a new species from Thailand associated with Pseudogibellula formicarum (Cordycipitaceae), and their bioactive secondary metabolites

During a diversity study of entomopathogenic fungi in an agricultural ecosystem, two fungi were collected, isolated, and identified based on molecular phylogenetic analyses of three nuclear loci (LSU, TEF1, and RPB1) combined with morphological data. In this study, one novel species is described, Ophiocordyceps flavida, and a new record of Pseudogibellula formicarum for Thailand. Ophiocordyceps flavida morphologically resembles the Hirsutella anamorph of Ophiocordyceps pruinosa by having a mononematous character of the conidiophores and the same insect host (Hemiptera: Cicadellidae). Pseudogibellula formicarum is found to occur simultaneously with O. flavida, producing white conidiophores on the host. Additionally, secondary metabolites of both fungi were investigated and the major compound in O. flavida was identified as 2-[2-(4-chlorophenyl)ethyl]-2-(1,1-dimethylethyl)-oxirane. Pseudogibellula formicarum from Ghana and Thailand produces 6-methoxy-1H-indole-3-carbonitrile as a main component. These compounds are known from chemical synthesis or as products of biotransformation, respectively. However, they were obtained in our study as genuine fungal metabolites for the first time and may even constitute chemotaxonomic markers for the respective speciesNational Center for Genetic Engineering and Biotechnolog

Disentangling cryptic species with isaria-like morphs in Cordycipitaceae

<p>A new genus and eight new species, all with isaria-like phialides, are described in Cordycipitaceae from Thailand. The new genus, <i>Samsoniella</i>, is segregated from <i>Akanthomyces</i> based on morphological and molecular evidence. <i>Samsoniella</i> differs from <i>Akanthomyces</i> in producing orange cylindrical to clavate stromata with superficial perithecia and orange conidiophores with isaria-like phialides and white to cream conidia. A new combination for CBS 240.32, originally identified as <i>Paecilomyces farinosus</i> (<i>Isaria farinosa</i>), and CBS 262.58, originally identified as <i>Penicillium alboaurantium</i>, respectively, is made in <i>Samsoniella</i>. Two new species, <i>Samsoniella aurantia</i> and <i>S. inthanonensis</i>, are described from lepidopteran larvae. Two new species of <i>Cordyceps, C. blackwelliae</i> and <i>C. lepidopterorum</i>, were also found on coleopteran and lepidopteran larvae. Both produce isaria-like morphs with globose phialides and attenuated long necks and white mycelium in culture. The authors established a sexual-asexual link for <i>Cordyceps javanica</i> (= <i>Isaria javanica</i>) on lepidopteran larvae. Four new species, <i>Akanthomyces kanyawimiae, A. sulphureus, A. thailandicus</i>, and <i>A. waltergamsii</i>, were pathogenic on spiders, with some strains of <i>A. kanyawimiae</i> also found on unidentified insect larvae. These four species of <i>Akanthomyces</i> occur on the underside of leaves and produce white to cream white powdery conidia, whereas <i>S. aurantia</i> and <i>S. inthanonensis</i> were found in leaf litter and produce bright orange stromata and synnemata with white conidia. Another new combination, <i>Akanthomyces ryukyuensis</i>, is proposed. Phylogenetic analyses based on a combined data set comprising the nuc rDNA region encompassing the internal transcribed spacers 1 and 2 along with the 5.8S rDNA (ITS), nuc 28S rDNA (28S), partial sequences of translation elongation factor 1-α gene (<i>TEF1</i>), and the genes for RNA polymerase II largest (<i>RPB1</i>) and second-largest (<i>RPB2</i>) subunits strongly support the delimitation of these new species of <i>Cordyceps, Akanthomyces</i>, and in a new genus <i>Samsoniella</i> in Cordycipitaceae.</p