Molecular phylogenies using 1-4 gene regions and information on ecology, morphology and pigment chemistry were used in a partial revision of the agaric family Hygrophoraceae. The phylogenetically supported genera we recognize here in the Hygrophoraceae based on these and previous analyses are: Acantholichen, Ampulloclitocybe, Arrhenia, Cantharellula, Cantharocybe, Chromosera, Chrysomphalina, Cora, Corella, Cuphophyllus, Cyphellostereum, Dictyonema, Eonema, Gliophorus, Haasiella, Humidicutis, Hygroaster, Hygrocybe, Hygrophorus, Lichenomphalia, Neohygrocybe, Porpolomopsis and Pseudoarmillariella. A new genus that is sister to Chromosera is described as Gloioxanthomyces. Revisions were made at the ranks of subfamily, tribe, genus, subgenus, section and subsection. We present three new subfamilies, eight tribes (five new), eight subgenera (one new, one new combination and one stat. nov.), 26 sections (five new and three new combinations and two stat. nov.) and 14 subsections (two new, two stat. nov.). Species of Chromosera, Gliophorus, Humidicutis, and Neohygrocybe are often treated within the genus Hygrocybe; we therefore provide valid names in both classification systems. We used a minimalist approach in transferring genera and creating new names and combinations. Consequently, we retain in the Hygrophoraceae the basal cuphophylloid grade comprising the genera Cuphophyllus, Ampulloclitocybe and Cantharocybe, despite weak phylogenetic support. We include Aeruginospora and Semiomphalina in Hygrophoraceae based on morphology though molecular data are lacking. The lower hygrophoroid clade is basal to Hygrophoraceae s.s., comprising the genera Aphroditeola, Macrotyphula, Phyllotopsis, Pleurocybella, Sarcomyxa, Tricholomopsis and Typhula.

Bradyrhizobium sp. S23321 is an oligotrophic bacterium isolated from paddy field soil. Although S23321 is phylogenetically close to Bradyrhizobium japonicum USDA110, a legume symbiont, it is unable to induce root nodules in siratro, a legume often used for testing Nod factor-dependent nodulation. The genome of S23321 is a single circular chromosome, 7,231,841 bp in length, with an average GC content of 64.3%. The genome contains 6,898 potential protein-encoding genes, one set of rRNA genes, and 45 tRNA genes. Comparison of the genome structure between S23321 and USDA110 showed strong colinearity; however, the symbiosis islands present in USDA110 were absent in S23321, whose genome lacked a chaperonin gene cluster (groELS3) for symbiosis regulation found in USDA110. A comparison of sequences around the tRNA-Val gene strongly suggested that S23321 contains an ancestral-type genome that precedes the acquisition of a symbiosis island by horizontal gene transfer. Although S23321 contains a nif (nitrogen fixation) gene cluster, the organization, homology, and phylogeny of the genes in this cluster were more similar to those of photosynthetic bradyrhizobia ORS278 and BTAi1 than to those on the symbiosis island of USDA110. In addition, we found genes encoding a complete photosynthetic system, many ABC transporters for amino acids and oligopeptides, two types (polar and lateral) of flagella, multiple respiratory chains, and a system for lignin monomer catabolism in the S23321 genome. These features suggest that S23321 is able to adapt to a wide range of environments, probably including low-nutrient conditions, with multiple survival strategies in soil and rhizosphere.

Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands.

Polyporus accommodates morphologically heterogeneous species and is divided into six infrageneric groups based on macromorphological characters. On the other hand allied genera have macro- and microscopic characters similar to those of Polyporus. The phylogenetic relationships of Polyporus and allied genera were established from sequences of RNA polymerase II second largest subunit (RPB2), nuclear ribosomal large subunit (nucLSU) and mitochondrial ATPase subunit 6 (ATP6). The molecular phylogenetic trees confirmed that Polyporus is a polyphyletic genus and recognized six major clades (1-6) containing species of Polyporus and several allied genera. Among the clades one contained three infrageneric groups of Polyporus and two allied genera, Datronia and Pseudofavolus while one other contained group Polyporellus and Lentinus. Five of the six major clades contained species belonging to a single infrageneric group, Favolus, Melanopus, Polyporellus or Polyporus. This suggests that morphological characters used to define these groups have phylogenetic significance and reveals the need for a taxonomic revision of Polyporus and its allied genera.

No abstract