Four putative entomopathogenic fungi of armoured scale insects on <Emphasis Type="Italic">Citrus</Emphasis> in Australia

This study led to the discovery of four putative entomopathogenic fungi of armoured scale insects on citrus trees in coastal New South Wales. Two of these species belong in Podonectria as P. coccicola (Ellis & Everh.) Petch (syn. Tetracrium coccicola (Höhn.) Ellis & Everh.) and P. novae-zelandiae Dingley. Members of this genus are grown in culture for the first time. Formerly placed in the Pleosporales, Tubeufiaceae, or more recently in the Tubeufiales, these species are herein placed in the new family Podonectriaceae fam. nov., Pleosporales. Another species is placed in the Hypocreales, Bionectriaceae as Clonostachys coccicola (J.A. Stev.) H.T. Dao comb. nov. (basionym Tubercularia coccicola J.A. Stev., syn. Nectria tuberculariae Petch). The fourth species is Myriangium citri Henn. (Myriangiales, Myriangiaceae). Each fungal species is characterized and the phylogenetic placement confirmed by molecular analyses of the ITS and 28 s rDNA regions. In addition, their biology is noted, including location of the fungi within tree canopies.     

A new species of <Emphasis Type="Italic">Cosmospora</Emphasis> and the first record of sexual state of <Emphasis Type="Italic">C. lavitskiae</Emphasis>

A new fungicolous species, Cosmospora inonoticola, is described and illustrated based on a specimen collected from northeast China. It is characterized by the occurrence of fruitbodies of Inonotus sp.; perithecia nonstromatic, subglobose to pyriform, not collapsing when dry; clavate asci containing (3–)6(?8) spores; ascospores ellipsoidal to broadly ellipsoidal, pale brown, finely warted, bicellular, conspicuously constricted at septum; and producing a verticillium-like asexual state. A multi-locus analysis of the combined ITS, rpb1 and tub sequences confirmed its taxonomic position, and revealed the distinction from its morphologically similar species including the type species, C. coccinea, which occurs also on Inonotus. A specimen with sexual state of C. lavitskiae is reported for the first time, and a reference specimen is indicated.     

An unusual <Emphasis Type="Italic">Lophodermium</Emphasis> species on needles of <Emphasis Type="Italic">Pinus taiwanensis</Emphasis> from China

An interesting fungus, which appeared to resemble a contaminated or infected Lophodermium species, is described and illustrated in this paper. The circinate apex of paraphyses, which intertwined with each other, and the broad slit exposing the unusual-white hymenium distinguished the new species from other known Lophodermium species. Evidence from two markers including internal transcribed spacer (ITS) region and the partial Actin gene indicated that L. pini-taiwanensis was in a robust and separate clade. It is, therefore, described as a new Lophodermium species.     

Isolation and molecular characterization of the fungal endophytic microbiome from conventionally and organically grown avocado trees in South Florida

Fungal endophytes are the most ubiquitous and highly diverse microorganisms that inhabit the interior of healthy plants. They are important in plant ecology and offer untapped potential to improve plant health and productivity in agroecosystems. The endophytic assemblage of avocado is poorly understood; therefore, surveys of fungal endophytes of Persea americana Mill. (Avocado) in South Florida organic and conventional orchards were conducted. A total of 17 endophytic fungal species were recovered from healthy avocado terminal branches. Endophytic fungal species were identified by rDNA sequencing of the internal transcribed spacer (ITS) region, using UNITE Species Hypotheses to reliably assign a taxon name, and determined as belonging to the genera Alternaria, Cladosporium, Colletotrichum, Corynespora, Diaporthe, Lasiodiplodia, Neofusicoccum, Neopestalotiopsis, Phyllosticta, and Strelitziana. Endophyte community assemblage differed between organic and conventional agroecosystems. This is the first report of Alternaria eichhorniae, Cladosporium tenuissimum, Corynespora cassiicola, Colletotrichum alatae, Diaporthe fraxini-angustifoliae, Lasiodiplodia gonubiensis, Neofusicoccum algeriense, Neofusicoccum andinum, Neopestalotiopsis foedans, Phyllosticta capitalensis, and Strelitziana africana as endophytes of avocado. Evaluation using pathogenicity tests on avocado leaves and terminal branches showed that endophytic fungal isolates did not cause disease symptoms.     

Taxonomic and phylogenetic placement of <Emphasis Type="Italic">Nodulosphaeria</Emphasis>

Nodulosphaeria is a ubiquitous genus that comprises saprobic, endophytic and pathogenic species associated with a wide variety of substrates and has 64 species epithets listed in Index Fungorum. The classification of species in the genus has been a major challenge due to a lack of understanding of the importance of characters used to distinguish taxa, as well as the lack of reference strains. The present study clarifies the phylogenetic placement of the genus and related species, using fresh collections from Italy. Four Nodulosphaeria species are characterized based on multi-loci analyses of ITS, LSU, SSU, TEF and RPB2 sequence datasets. Phylogenetic analyses indicate that Nodulosphaeria species group within the family Phaeosphaeriaceae as a distinct genus. The sexual morphs of Nodulosphaeria hirta and N. spectabilis are described and illustrated using modern concepts. Two new Nodulosphaeria species are introduced. The phylogenetic relationships and taxonomy of the genus Nodulosphaeria are discussed, but further sampling with fresh collections, reference or ex-type strains and molecular data are needed to obtain a better and natural classification for the genus.     

The biosynthesis of gibberellic acids by the transformants of orchid-associated <Emphasis Type="Italic">Fusarium oxysporum</Emphasis>

The genus Fusarium, including multiple strains in the Gibberella fujikuroi species complex (GFC), is well known for its production of diverse secondary metabolites. F. fujikuroi, associated with the “bakanae” disease of rice, is an active producer of gibberellins (GAs), a wide class of plant hormones. In addition to some members of the GFC, the GA biosynthetic gene cluster, or parts of it, occurs also in some isolates of the closely related species of F. oxysporum, which does not belong to the GFC. However, production of GAs has never been observed in any F. oxysporum strain. In this study, we report on the GA biosynthetic activity in an orchid-associated F. oxysporum strain by transforming a cosmid with the entire F. fujikuroi GA gene cluster. Southern and Northern blot analyses confirmed not only the integration of the entire gene cluster into the genome but also the active expression of the seven GA biosynthetic genes under nitrogen-limiting conditions. The transformants produced GAs at levels similar to those of F. fujikuroi. These data show that the regulatory network for expression of GA genes is fully active in the F. oxysporum background.     

New species and reports of <Emphasis Type="Italic">Hypoxylon</Emphasis> from Argentina recognized by a polyphasic approach

A preliminary account of Hypoxylon species (Xylariaceae) from the hitherto widely unexplored “Yungas” mountain forests of Northwest Argentina is presented. Two new species are described based on extensive morphological, molecular (ITS region of rDNA, partial β-tubulin gene) and chemotaxonomic data. Hypoxylon spegazzinianum is close to H. erythrostroma, but differs by larger ascospores and a virgariella-like asexual morph. Hypoxylon calileguense resembles H. subgilvum when growing on wood, but can be distinguished by larger ascospores and a fawn to brick stromatal surface colour. Stromata found on bark have affinities to H. pelliculosum, but differ in their stromatal surface colour and conspicuous amyloid apical apparatus. In addition, nine taxa of Hypoxylon are reported for Argentina for the first time, and some details on their asexual state and stromatal secondary metabolites are reported. An updated dichotomous key for Hypoxylon species from Argentina is provided.