Yukio Harada

A class-wide phylogenetic assessment of Dothideomycetes

We present a comprehensive phylogeny derived from 5 genes, nucSSU, nucLSU rDNA, TEF1, RPB1 and RPB2, for 356 isolates and 41 families (six newly described in this volume) in Dothideomycetes. All currently accepted orders in the class are represented for the first time in addition to numerous previously unplaced lineages. Subclass Pleosporomycetidae is expanded to include the aquatic order Jahnulales. An ancestral reconstruction of basic nutritional modes supports numerous transitions from saprobic life histories to plant associated and lichenised modes and a transition from terrestrial to aquatic habitats are confirmed. Finally, a genomic comparison of 6 dothideomycete genomes with other fungi finds a high level of unique protein associated with the class, supporting its delineation as a separate taxon.

Molecular taxonomy of bambusicolous fungi: Tetraplosphaeriaceae, a new pleosporalean family with Tetraploa-like anamorphs.

A new pleosporalean family Tetraplosphaeriaceae is established to accommodate five new genera; 1) Tetraplosphaeria with small ascomata and anamorphs belonging to Tetraploa s. str., 2) Triplosphaeria characterised by hemispherical ascomata with rim-like side walls and anamorphs similar to Tetraploa but with three conidial setose appendages, 3) Polyplosphaeria with large ascomata surrounded by brown hyphae and anamorphs producing globose conidia with several setose appendages, 4) Pseudotetraploa, an anamorphic genus, having obpyriform conidia with pseudosepta and four to eight setose appendages, and 5) Quadricrura, an anamorphic genus, having globose conidia with one or two long setose appendages at the apex and four to five short setose appendages at the base. Fifteen new taxa in these genera mostly collected from bamboo are described and illustrated. They are linked by their Tetraploa s. l. anamorphs. To infer phylogenetic placement in the Pleosporales, analyses based on a combined dataset of small- and large-subunit nuclear ribosomal DNA (SSU+LSU nrDNA) was carried out. Tetraplosphaeriaceae, however, is basal to the main pleosporalean clade and therefore its relationship with other existing families was not completely resolved. To evaluate the validity of each taxon and to clarify the phylogenetic relationships within this family, further analyses using sequences from ITS-5.8S nrDNA (ITS), transcription elongation factor 1-α (TEF), and β-tubulin (BT), were also conducted. Monophyly of the family and that of each genus were strongly supported by analyses based on a combined dataset of the three regions (ITS+TEF+BT). Our results also suggest that Tetraplosphaeria (anamorph: Tetraploa s. str.) is an ancestral lineage within this family. Taxonomic placement of the bambusicolous fungi in Astrosphaeriella, Kalmusia, Katumotoa, Massarina, Ophiosphaerella, Phaeosphaeria, Roussoella, Roussoellopsis, and Versicolorisporium, are also discussed based on the SSU+LSU phylogeny.

Revision of the Massarineae (Pleosporales, Dothideomycetes)

We here taxonomically revise the suborder Massarineae (Pleosporales, Dothideomycetes, Ascomycota). Sequences of SSU and LSU nrDNA and the translation elongation factor 1-alpha gene (tef1) are newly obtained from 106 Massarineae taxa that are phylogenetically analysed along with published sequences of 131 taxa in this suborder retrieved from GenBank. We recognise 12 families and five unknown lineages in the Massarineae. Among the nine families previously known, the monophyletic status of the Dictyosporiaceae, Didymosphaeriaceae, Latoruaceae, Macrodiplodiopsidaceae, Massarinaceae, Morosphaeriaceae, and Trematosphaeriaceae was strongly supported with bootstrap support values above 96 %, while the clades of the Bambusicolaceae and the Lentitheciaceae are moderately supported. Two new families, Parabambusicolaceae and Sulcatisporaceae, are proposed. The Parabambusicolaceae is erected to accommodate Aquastroma and Parabambusicola genera nova, as well as two unnamed Monodictys species. The Parabambusicolaceae is characterised by depressed globose to hemispherical ascomata with or without surrounding stromatic tissue, and multi-septate, clavate to fusiform, hyaline ascospores. The Sulcatisporaceae is established for Magnicamarosporium and Sulcatispora genera nova and Neobambusicola. The Sulcatisporaceae is characterised by subglobose ascomata with a short ostiolar neck, trabeculate pseudoparaphyses, clavate asci, broadly fusiform ascospores, and ellipsoid to subglobose conidia with or without striate ornamentation. The genus Periconia and its relatives are segregated from the Massarinaceae and placed in a resurrected family, the Periconiaceae. We have summarised the morphological and ecological features, and clarified the accepted members of each family. Ten new genera, 22 new species, and seven new combinations are described and illustrated. The complete ITS sequences of nrDNA are also provided for all new taxa for use as barcode markers.

Pleosporales in Japan (1) : the genus Lophiostoma

Abstract Seven species of the genus Lophiostoma were the subject of this study. Among these, Lophiostoma mucosum is described and illustrated as a new species. All other species, L. macrostomum, L. semiliberum, L. arundinis, L. caulium, L. caudatum, and L. winteri, are reported for the first time in Japan. A key to the species of Lophiostoma in Japan is given.

Botryosphaeria spp. isolated from apple and several deciduous fruit trees are divided into three groups based on the production of warts on twigs, size of conidia, and nucleotide sequences of nuclear ribosomal DNA ITS regions.

We examined the phytopathological and biological characters ofBotryosphaeria spp. isolated from apples and other deciduous fruit trees, and determined the nucleotide sequences of their rDNA ITS regions. TheBotryosphaeria isolates from deciduous fruit trees can be divided into three groups based on their production of warts on twigs, size of the conidia, and nucleotide sequences of rDNA ITS 1, ITS 2 and 5.8S rDNA. Isolates ofBotryosphaeria in ITS group A produced conidia of intermediate size and showed warts on infected twigs prior to the development of ring rot on fruit. This group was common on deciduous fruit trees in Japan as a causal agent of ring rot and wart bark diseases of apples and pears; and it appears similar to theB. dothidea from the US that was isolated from apple exhibiting white rot. The ITS group BBotryosphaeria produced small conidia and induced shoot blight without wart development prior to the development of ring rot on fruit. This group was localized on pear, persimmon, and kiwi fruit in restricted areas of Japan. The ITS group CBotryosphaeria consisted ofB. obtusa, the causal agent of apple black rot in the US, which produced large dark brown conidia.

Isolation and Properties of Two Antifungal Substances from Fusarium solani

An antagonistic fungus to Valsa ceratosperma was isolated from soil, and identified as Fusarium solani. The fungus was found to produce at least two antifungal substances in stationary culture. These two substances were isolated from their culture filtrate as chromatographically homogeneous, amorphous solids. Their examined physico-chemical properties appeared to be identical with cyclosporin A and C, obtained from the fermentation broth of Trichoderma polysporum, and they showed a pronounced inhibitory effect on growth of V. ceratosperma.

Monilia mumecola, a new brown rot fungus on Prunus mume in Japan

In 1982, an anamorphic fungus in the genus Monilia was first isolated as the causal agent of brown rot disease of Japanese apricot or mume (Prunus mume) in Oita Prefecture, Kyushu, Japan. Inoculation of flowers, shoots, and fruit of P. mume with the fungus reproduced brown rot disease symptoms similar to those found in nature. The fungus somewhat resembled the colony appearance of Monilinia (anamorph Monilia) laxa, the apricot brown rot fungus, on PSA plates, but it differed from the latter and the other two brown rot fungi, M. fructigena and M. fructicola, in terms of growth rate, temperature optima for mycelial growth and sporulation, morphology and germination pattern of conidia, nuclear number in the conidium, and nucleotide sequences in the ITS region of ribosomal DNA. It is newly described as Monilia mumecola Y. Harada, Y. Sasaki & T. Sano. A key to anamorphic states of four brown rot fungi of fruit trees is provided.

Three new freshwater ascomycetes from rivers in Akkeshi, Hokkaido, northern Japan

Three lignicolous freshwater ascomycetes from rivers in Akkeshi, Hokkaido, northern Japan are reported. All of these are new species belonging to the Lophiostomataceae and described as Lophiostoma breviappendiculatum, Massarina clionina, and Massariosphaeria maxima. Morphological differences between each species and its similar taxa are noted. All three species have been observed to produce only ascomatal states in artificial culture.

Bambusicolous fungi in Japan (3): a new combination, Kalmusia scabrispora

Leptosphaeria scabrispora collected from Phyllostachys bambusoides is reported from Japan. This species was described initially from China and has not been reported subsequently. Based on the morphological features of clypeate ascomata, long stipitate asci, and reddish-brown ascospores with median primary septum, it is transferred to the genus Kalmusia. The fungus produced a Leptodothiorella-like microconidial state in culture.

Taxonomic revision of Pseudolachnea and Pseudolachnella and establishment of Neopseudolachnella and Pseudodinemasporium gen. nov.

The taxonomy of Pseudolachnea and Pseudolachnella is controversial. Some authors have regarded them as congeneric, whereas others have considered them to be distinct genera differentiated merely on the number of conidial septa. A total of 26 isolates of Pseudolachnea-like fungi were subjected to morphological examination and phylogenetic analyses of nuc rDNA internal transcribed spacers 1 and 2 and partial 28S sequences and partial sequence of the translation elongation factor 1α gene. The results indicated that our materials should be classified in four genera: Pseudolachnea, Pseudolachnella, and two new genera, Neopseudolachnella and Pseudodinemasporium. Although the monophyly of both Pseudolachnea and Pseudolachnella was confirmed, it was concluded that differences observed in the conidiomatal structure, such as thickness of basal stroma and the excipulum, were more reliable for their circumscription, instead of conidial septation. Neopseudolachnella was similar to Pseudolachnea and Pseudolachnella in conidial morphology but was characterized by the conidiomata lacking an excipulum, unlike members of the latter two genera. Pseudodinemasporium bore conidia morphologically similar to those of Dinemasporium but was differentiated from the latter by the conidiomata, which was composed of a well developed peridial structure. A total of 12 new species, namely three in Neopseudolachnella (N. acutispora, N. magnispora, N. uniseptata), one in Pseudodinemasporium (P. fabiforme) and eight in Pseudolachnella (P. asymmetrica, P. botulispora, P. brevicoronata, P. campylospora, P. complanata, P. falcatispora, P. fusiformis and P. pachyderma) are described and illustrated.