Taxonomic studies of nectrioid fungi in Japan. I: The genus Neonectria

Five species of the genus Neonectria (Nectriaceae, Hypocreales) collected from Japan are described with discussion and illustrated. Among them, one found on dead twigs of a broad-leaved tree is described as a new species, Neonectria tokyoensis (anamorph: Cylindrocarpon tokyoense). Neonectria cinnamomea and Neo. discophora are newly added to the Japanese mycobiota. Nectria azureo-ostiolata, recorded in 1977 from Japan, is reexamined as a synonym of Neo. jungneri. Neonectria radicicola, teleomorph of Cy. destructans, a well-known soil-borne plant pathogen in Japan, is newly recorded from Japan. Additional distribution records are provided for the Neonectria species hitherto recorded in Japan.     

Cyanonectria, a new genus for Nectria cyanostoma and its Fusarium anamorph

The new genus Cyanonectria is proposed for Nectria cyanostoma (≡ Cyanonectria cyanostoma comb. nov.). This genus is characterized by Nectria-like, red perithecia that have a bluish-purple papilla and a Fusarium anamorph. DNA sequences (large subunit and internal transcribed spacers of the nuclear rDNA) indicate that C. cyanostoma is not closely related to Nectria sensu stricto. In addition, the phylogenetic data also show that the closest relatives for Cyanonectria also have Fusarium anamorphs. Taxonomic novelties Cyanonectria Samuels & Chaverri, Cyanonectria cyanostoma (Sacc. & Flageolet) Samuels & Chaverri     

我国丛赤壳类真菌分类研究

丛赤壳类真菌是具有经济重要性的生物类群。该文回顾了我国该类分类研究的简史,概述近年来取得的相关研究进展,揭示我国该类真菌的物种丰富程度,展示建立在分类学基础上的真菌DNA条形码探索以及分子系统学研究成果,表明资源和分类研究与真菌天然产物研究联手的新发现。     

Neonectria amamiensis and Cylindrocarpon amamiense, a new nectrioid fungus and its sporodochial anamorph on Pinus luchuensis from Japan

A new nectrioid fungus with its sporodochial Cylindrocarpon anamorph, collected on dead bark of Luchu pines (Pinus luchuensis) in the southern part of Japan (Kagoshima and Okinawa), having perithecia slightly constricted just below the papilla and conidia with a strongly hooked and acute apical cell, belongs to the genus Neonectria according to the recent concept of the Nectriaceae (Hypocreales). Molecular phylogenetic analysis based on the tub2 region of β-tubulin genes also supports the morphological consideration. This fungus is described as Neonectria amamiensis (anamorph: Cylindrocarpon amamiense).     

Taxonomic studies of nectrioid fungi in Japan. III. The genus <Emphasis Type="Italic">Cosmospora</Emphasis>

Seven species of the genus Cosmospora collected in Japan are reported in this article. Among them, Cosmospora japonica is described as a new species. Cosmospora henanensis, C. rishbethii, and C. triqua, all of which are known only from their type localities, are added to the Japanese mycobiota. The other species, C. chaetopsinaecatenulatae, C. diminuta, and C. peponum, are new records for Japan. Additional distribution records are given for Cosmospora species hitherto known in Japan.     

Pseudocospeciation of the mycoparasite Cosmospora with their fungal hosts

Species of Cosmospora are parasites of other fungi (mycoparasites), including species belonging to the Xylariales. Based on prior taxonomic work, these fungi were determined to be highly host specific. We suspected that the association of Cosmospora and their hosts could not be a result of random chance, and tested the cospeciation of Cosmospora and the their hosts with contemporary methods (e.g., ParaFit, PACo, and Jane). The cophylogeny of Cosmospora and their hosts was found to be congruent, but only host‐parasite links in more recent evolutionary lineages of the host were determined as coevolutionary. Reconciliation reconstructions determined at least five host‐switch events early in the evolution of Cosmospora. Additionally, the rates of evolution between Cosmospora and their hosts were unequal. This pattern is more likely to be explained by pseudocospeciation (i.e., host switches followed by cospeciation), which also produces congruent cophylogenies.     

沉水玛利亚霉新种以及链状玛利亚霉的新生境记录

通过形态特征与系统发育分析(LSU和ITS),报道了玛利亚霉属Mariannaea的1个新种和1个新记录种.新种沉水玛利亚霉Mariannaea submersa的主要形态特征为透明、分支状的分生孢子梗上带有3-6个环生瓶梗,产孢细胞烧瓶形至锥形,分子孢子为宽梭形至卵圆形,无隔膜,颜色透明且带有尖锐顶部和截断底部.链状...     

Seed Rot,a New Disease of Beech Tree Caused by Neonectria ramulariae (anamorph: Cylindrocarpon obtusiusculum)

During a survey of seed diseases of Fagus crenata, a new fungal disease of the seeds was found with high frequency in Akita, northern Japan. Main symptoms are often expressed as browning of the cracked parts from exposed cotyledons and complete loss of viability of infected seeds. Reddish perithecia and whitish yellow sporodochia were occasionally observed symptoms and determined that they were anamorph–telemorph relationship on the basis of both cultural observations. Inoculation studies confirmed that this fungus was the cause of seed rot. The fungus is morphologically identical with Neonectria ramulariae (anamorph: Cylindrocarpon obtusiusculum) that is well known as the soil‐born fungi around the world. Sequences between the authentic isolate of Neo. ramulariae (CBS 151.29) and the pathogenic fungus based on ITS, LSU and tub showed high similarity. Thus, ‘seed rot’, the new disease of beech seeds caused by Neo. ramulariae (anamorph: Cyl. obtusiusculum) was proposed in this study.     

Culturable mycobiome of soya bean cyst nematode (Heterodera glycines) cysts from a long-term soya bean-corn rotation system is dominated by Fusarium

The cyst of the soya bean cyst nematode (SCN; Heterodera glycines), an economically important pathogen of soya beans worldwide, represents a unique microhabitat in soil. The fungi inhabiting cysts may include natural antagonists of the SCN as well as saprotrophs and other opportunists. This study aimed to characterise the entire culturable mycobiome of SCN cysts obtained from a long-term soya bean-corn rotation experiment using ITS fungal barcoding. Fusarium was consistently the most frequently isolated taxon across all sampling time points and crop sequences, followed by Ilyonectria. Among fourteen genera frequently isolated from SCN cysts, five fell within the single family Nectriaceae (Sordariomycetes) and five within the order Pleosporales (Dothideomycetes), suggesting independent evolutionary origins and shared adaptations in these groups towards colonisation of SCN cysts. Six genera (Pochonia, Clonostachys, Fusarium, Neonectria, Alternaria, and Leptosphaeria) varied significantly by crop sequence in at least one year.