Myxomycetes (slime molds) are unique eukaryotic microorganisms with both characteristics of fungi and amoebae. Artificial cultures grown under controlled conditions were used to study the life cycle and morphogenesis. Physarum pusillum was collected from the field. Spores were inoculated and cultured with the hanging drop method. The complete life cycle was observed from spore to spore on agar without adding any solid nutrients or bacteria as food. Life cycle morphological characteristics were described for spore germination, myxamoebae, zygote, plasmodium and sporangia formation.

To better understand the functions of key genes involved in triterpene biosynthesis in Ganoderma lucidum, we cloned and characterized an acetyl coenzyme A acetyltransferase gene (AACT), designated Ganoderma lucidum AACT (Gl-aact). The open reading frame (ORF) of Gl-aact encoded a 417-amino acid polypeptide with a theoretical pI of 8.89. The Gl-AACT sequence was highly homologous to those of other fungal AACTs. Meanwhile, analysis of the Gl-aact expression profile revealed a positive correlation between Gl-aact transcript abundance and triterpene content changes during the development of G. lucidum. The treatment of mycelia with exogenous methyl jasmonate (MeJA) caused the accumulation of Gl-aact messenger RNA. Gl-aact over-expressing transformants were obtained by Agrobacterium tumefaciens-mediated transformation (ATMT), and triterpene production was observed to be increased when Gl-aact was over-expressed. Our results suggest that this enzyme may play an important role in triterpene biosynthesis.

Misturatosphaeria mariae is described as new from a Robinia pseudoacacia post in southern France. Relationships with other species of Misturatosphaeria are discussed based on morphology and 28S nrDNA sequence comparisons. The geographic distribution of Misturatosphaeria species is also given and discussed and a key to species is provided.

Two new species collected in northern Thailand are herein described and discussed. Tortulomyces thailandicus is the type of a new genus characterized by a combination of such features as a dense subiculum, non-ostiolate ascomata, two kinds of paraphyses (filiform and bead-like), and 1-septate, brown ascospores. Nitschkia siamensis has non-ostiolate, turbinate and stalked ascomata and hyaline, often slightly curved, 1-septate ascospores.

Inonotus amazonicus is described and illustrated as a new species based on specimens collected in Aripuanã, in the state of Mato Grosso, Brazil, and deposited in herbarium INPA 34 years ago. This species is mainly distinguished from the others in the genus by the abundant, huge tramal setae and the duplex context covered by a persistent adpressed dark brown tomentum. Besides the description of the new species, one new combination is proposed: I. calcitratus, I. luteoumbrinus and Phylloporia spathulata are reported as new to the state of Roraima, P. chrysita to the state of Amazonas and P. pectinata to the state of Rondônia. Description and illustration of the new species and keys to the species of Inonotus and Phylloporia known to Brazil are provided.

We examined arbuscular mycorrhizal (AM) fungi colonizing the roots of Stipa krylovii, a grass species dominating the grasslands of the steppe zone in Hustai and Uvurkhangai in Mongolia. The AM fungal communities of the collected S. krylovii roots were examined by molecular analysis based on the partial sequences of a small subunit of ribosomal RNA gene as well as AM fungal colonization rates. Almost all AM fungi detected were in Glomus-group A, and were divided into 10 phylotypes. Among them, one phylotype forming a clade with G. intraradices and G. irregulare was the most dominant. Furthermore, it was also found that most of the phylotypes include AM fungi previously detected in high altitude regions in the Eurasian Continent. Significant correlations were found among soil total N, total plant biomass and AM fungal colonization ratio, which suggested that higher plant biomass may be required for the proliferation of AM fungi in the environment. Meanwhile, redundancy analysis on AM fungal distribution and environmental variables suggested that the effect of plant biomass and most soil chemical properties on the AM fungal communities were not significant.

Pythiogeton is a little-studied genus of pythialean Oomycete. The genus is characterized by producing its zoospores outside of the sporangium within an apparently naked protoplasmic mass, which formed from a discharge tube-vesicle complex. A total of nine morphologically distinct Pythiogeton species were identified, of which six were new species (Pythiogeton abundans, Pythiogeton microzoosporum, Pythiogeton oblongilobum, Pythiogeton paucisporum, Pythiogeton proliferatum, and Pythiogeton puliensis). A phylogenetic analysis based on internal transcribed spacer sequences revealed that all isolates of Pythiogeton formed a highly supported clade, nested within the wider clade of Pythium species. Each newly recognized Pythiogeton species that was established on the basis of morphological characters was found to occur in a well-supported subgroup within the Pythiogeton clade, confirming their assignment to new species. Pythiogeton shares a common ancestor with the monophyletic group of Pythium species that have predominantly filamentous sporangia rather than with the separate clade of Pythium species that have predominantly globose or ovoid sporangia. This study confirms that Pythium is an extremely heterogenous and polyphyletic genus containing a number of distinct clades of species, including Pythiogeton, which possess morphologically distinguishable characters. A synoptic key to all the described Pythiogeton species is provided.

Heterotrimeric GTP-binding proteins (G proteins) and mitogen-activated protein kinase (MAPK) cascades involve vegetative hyphal growth, development of infection-related structure, colonization in host plant and female fertility in phytopathogenic ascomycete fungi. In this study, a heterotrimeric G protein β subunit (Gβ), GPB1, and MAPK, MPK1, were characterized from Fusarium sacchari (= Gibberella sacchari; mating population B of the G. fujikuroi-species complex). GPB1 and MPK1 showed high homology to known Gβ and Fus3/Kss1 MAP kinases of other filamentous ascomycetes, respectively. Disruption (Δ) of gpb1 suppressed hyphal branching and accelerated aerial hyphae formation in F. sacchari. Oppositely, disruption of mpk1 caused delayed aerial hyphae formation. These indicated that GPB1 regulates vegetative hyphal growth negatively, and MPK1 does positively in F. sacchari. Both Δgpb1 and Δmpk1 showed female sterility. Level of intracellular cAMP in Δgpb1 was lower than wild type. Exogenous cyclic AMP (cAMP) partially restored enhanced aerial hyphae formation. These suggested that abnormal hyphal growth was caused by depletion of intracellular cAMP in Δgpb1. cAMP has been reported to suppress development of perithecia in crossing between wild type strains. Thus, precise regulation of intracellular cAMP level via Gβ/MAPK is essential for normal hyphal growth and fertility.

Isaria poprawskii is described as a new entomopathogenic species similar to Isaria javanica (= Paecilomyces javanicus). It was discovered on the sweet potato whitefly, Bemisia tabaci biotype B in the Lower Rio Grande Valley of Texas (LRGV), USA. Morphological and DNA examinations indicated the distinctness of I. poprawskii from the ex-type isolate of I. javanica. I. poprawskii produced light yellow young colonies to darker yellow with a grayish-violet center to a taupe or a brownish-gray mature conidial mass; conidia hyaline, one-celled, 3.9 (2.9–4.6) μm long × 1.6 (1.4–2.1) μm wide; colored synnemata, but I. javanica ex-type produced white colony, hyaline conidia and no synnemata. A phylogenetic position of I. poprawskii was inferred by a nucleotide sequence analysis of β-tubulin along with standard β-tubulin sequences from GenBank. Fifteen unsequenced isolates, including eight from the LRGV, were investigated. The analysis confirmed that I. poprawskii could be recovered from LRGV fields, and that both I. javanica and I. poprawskii are present in the LRGV in sympatry. I. poprawskii was shown to be closely related to I. javanica; however, it formed its own unique clade, thus confirming its status as a new fungal species.