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Eucalyptus spp. in plantations are negatively affected by canker and wilt diseases caused by several species of Ceratocystis , particularly those in the Latin American Clade (LAC). Ceratocystis eucalypticola and Ceratocystis manginecans are of particular concern where disease epidemics are reported globally, with recent outbreaks emerging in South African and Indonesian Eucalyptus plantations. Consequently, a rapid screening protocol is required for these pathogens. In this study, a high-resolution melting curve analysis (HRMA) was developed to detect C. eucalypticola and C. manginecans that bypasses time-consuming isolation and post-PCR procedures. Primers targeting a 172 bp region of the cerato-platanin (CP) gene were designed. Using these primers, the accuracy of HRMA to detect and distinguish between these two LAC species was assessed using pure fungal DNA, and DNA extracted directly from Eucalyptus samples naturally infected with C. eucalypticola. The assay accurately detected the presence of C. eucalypticola and C. manginecans and quantifies their DNA, both from cultures, and directly from wood samples. HRMA further differentiated these two species from all other tested LAC individuals. This assay was also able to detect the presence of all the tested LAC species and distinguish seven of these, including C. fimbriata, to species level. Ceratocystis polyconidia was the only non-LAC off-target species detected. Based on these results, the developed assay can be used to rapidly identify C. eucalypticola and C. manginecans directly from infected plant material or fungal cultures, with the potential to also screen for several other LAC species. • Rapid diagnostic assay to detect and differentiate C. eucalypticola and C. manginecans in the form of a qPCR-HRMA assay. • The assay can identify C. eucalypticola and C. manginecans from fungal cultures or directly from infected plant material. • The assay shows the potential to be used for other species in the LAC. [ABSTRACT FROM AUTHOR]

Acacia mangium plantations in Sabah, Malaysia are seriously affected by a vascular wilt and canker disease caused by a species of Ceratocystis. A similar and devastating disease occurs in Indonesia and is caused by the fungal pathogen Ceratocystis manginecans. A closely related fungus, Ceratocystis fimbriata sensu stricto, is a common soil-borne pathogen of sweet potato (Ipomoea batatas) in areas of Malaysia where A. mangium is grown. This study characterised the species causing wilting on A. mangium and compared it with the I. batatas pathogen using DNA sequence-based comparisons used artificial inoculations to assess the effect of the A. mangium pathogen on Acacia auriculiformis and Acacia crassicarpa and considered the ability of the sweet potato pathogen to cause disease on the three Acacia species. DNA sequence comparisons confirmed that isolates from diseased A. mangium were C. manginecans and those on sweet potato were C. fimbriata s.s. Ceratocystis manginecans was pathogenic on all Acacia spp., with A. mangium being most susceptible followed by =A. auriculiformis and A. crassicarpa. Pathogenicity tests showed that C. fimbriata s.s. from sweet potato is not able to cause disease on any of the three Acacia spp. considered. This study also confirmed that C. manginecans is the primary cause of ceratocystis canker and wilt disease in Sabah and that the sweet potato fungus, C. fimbriata s.s., poses no threat to propagated Acacia spp. [ABSTRACT FROM AUTHOR]

Transcriptional regulation controls gene expression through regulatory promoter regions that contain conserved sequence motifs. These motifs, also known as regulatory elements, are critically important to expression, which is driving research efforts to identify and characterize them. Yeasts have been the focus of such studies in fungi, including in several in silico approaches. This study aimed to determine whether in silico approaches could be used to identify motifs in the Ceratocystidaceae family, and if present, to evaluate whether these correspond to known transcription factors. This study targeted the 1000 base-pair region upstream of the start codon of 20 single-copy genes from the BUSCO dataset for motif discovery. Using the MEME and Tomtom analysis tools, conserved motifs at the family level were identified. The results show that such in silico approaches could identify known regulatory motifs in the Ceratocystidaceae and other unrelated species. This study provides support to ongoing efforts to use in silico analyses for motif discovery. [ABSTRACT FROM AUTHOR]

The North American clade (NAC) of Ceratocystis includes pathogenic species that infect a wide range of woody hosts. Previous phylogenetic analyses have suggested that this clade includes cryptic species and a paraphyletic C. variospora. In this study, we used morphological data and phylogenetic analyses to characterize NAC taxa, including Ceratocystis isolates causing a serious disease of almond trees in California. Phylogenetic analyses based on six gene regions supported two new species of Ceratocystis. Ceratocystis destructans is introduced as the species causing severe damage to almond trees in California, and it has also been isolated from wounds on Populus and Quercus in Iowa. It is morphologically similar to C. tiliae, a pathogen on Tilia and the most recently characterized species in the NAC. Ceratocystis betulina collected from Betula platyphylla in Japan is also newly described and is the sister taxon to C. variospora. Our six-locus phylogenetic analyses and morphological characterization resolved several cryptic species in the NAC.

Fungal species of the Ceratocystidaceae grow on their host plants using a variety of different lifestyles, from saprophytic to highly pathogenic. Although many genomes of fungi in the Ceratocystidaceae are publicly available, it is not known how the genes that encode catechol dioxygenases (CDOs), enzymes involved in the degradation of phenolic plant defense compounds, differ among members of the Ceratocystidaceae. The aim of this study was therefore to identify and characterize the genes encoding CDOs in the genomes of Ceratocystidaceae representatives. We found that genes encoding CDOs are more abundant in pathogenic necrotrophic species of the Ceratocystidaceae and less abundant in saprophytic species. The loss of the CDO genes and the associated 3-oxoadipate catabolic pathway appears to have occurred in a lineage-specific manner. Taken together, this study revealed a positive association between CDO gene copy number and fungal lifestyle in Ceratocystidaceae representatives. [ABSTRACT FROM AUTHOR]

Two recently introduced fungal plant pathogens (Ceratocystis lukuohia and Ceratocystis huliohia) are responsible for Rapid 'ōhi'a Death (ROD) in Hawai'i. Despite being sexually incompatible, the two pathogens often co-occur in diseased 'ōhi'a sapwood, where genetic interaction is possible. We sequenced and annotated 33 mitochondrial genomes of the two pathogens and related species, and investigated 35 total Ceratocystis mitogenomes. Ten mtDNA regions [one group I intron, seven group II introns, and two autonomous homing endonuclease (HE) genes] were heterogeneously present in C. lukuohia mitogenomes, which were otherwise identical. Molecular surveys with specific primers showed that the 10 regions had uneven geographic distribution amongst populations of C. lukuohia. Conversely, identical orthologs of each region were present in every studied isolate of C. huliohia regardless of geographical origin. Close relatives of C. lukuohia lacked or, rarely, had few and dissimilar orthologs of the 10 regions, whereas most relatives of C. huliohia had identical or nearly identical orthologs. Each region included or worked in tandem with HE genes or reverse transcriptase/maturases that could facilitate interspecific horizontal transfers from intron-minus to intron-plus alleles. These results suggest that the 10 regions originated in C. huliohia and are actively moving to populations of C. lukuohia , perhaps through transient cytoplasmic contact of hyphal tips (anastomosis) in the wound surface of 'ōhi'a trees. Such contact would allow for the transfer of mitochondria followed by mitochondrial fusion or cytoplasmic exchange of intron intermediaries, which suggests that further genomic interaction may also exist between the two pathogens. [ABSTRACT FROM AUTHOR]

Terpenes represent the biggest group of natural compounds on earth. This large class of organic hydrocarbons is distributed among all cellular organisms, including fungi. The different classes of terpenes produced by fungi are mono, sesqui, di- and triterpenes, although triterpene ergosterol is the main sterol identified in cell membranes of these organisms. The availability of genomic data from members in the Ceratocystidaceae enabled the detection and characterization of the genes encoding the enzymes in the mevalonate and ergosterol biosynthetic pathways. Using a bioinformatics approach, fungal orthologs of sterol biosynthesis genes in nine different species of the Ceratocystidaceae were identified. Ergosterol and some of the intermediates in the pathway were also detected in seven species (Ceratocystis manginecans, C. adiposa, Huntiella moniliformis, Thielaviopsis punctulata, Bretziella fagacearum, Endoconidiophora polonica and Davidsoniella virescens), using gas chromatography-mass spectrometry analysis. The average ergosterol content differed among different genera of Ceratocystidaceae. We also identified all possible terpene related genes and possible biosynthetic clusters in the genomes used in this study. We found a highly conserved terpene biosynthesis gene cluster containing some genes encoding ergosterol biosynthesis enzymes in the analysed genomes. An additional possible terpene gene cluster was also identified in all of the Ceratocystidaceae. We also evaluated the sensitivity of the Ceratocystidaceae to a triazole fungicide that inhibits ergosterol synthesis. The results showed that different members of this family behave differently when exposed to different concentrations of triazole tebuconazole. [ABSTRACT FROM AUTHOR]

Huntiella species are wood-infecting, filamentous ascomycetes that occur in fresh wounds on a wide variety of tree species. These fungi are mainly known as saprobes although some have been associated with disease symptoms. Six fungal isolates with typical culture characteristics of Huntiella spp. were collected from wounds on native forest trees in Greece and South Africa. The aim of this study was to identify these isolates, using morphological characters and multigene phylogenies of the rRNA internal transcribed spacer (ITS) region, portions of the ß-tubulin (BT1) and translation elongation factor 1a (TEF-1a) genes. The mating strategies of these fungi were also determined through PCR amplification of mating type genes. The study revealed two new species; one from Platanus orientalis in Greece and one from Colophospermum mopane and Senegalia nigrescens in South Africa. These novel taxa have been provided with the names, H. hellenica sp. nov. and H. krugeri sp. nov., respectively. The former species was found to have a homothallic and the latter a heterothallic mating system. [ABSTRACT FROM AUTHOR]

Wilt and death of an E. grandis × E. urophylla variety was recently observed in the Zululand region of KwaZulu-Natal, South Africa. Symptoms on the dying trees included a streaking pattern of discolouration in the sapwood and cambium of stems and roots. A fungus resembling a Ceratocystis sp. was consistently found sporulating on diseased material and isolated from the symptomatic root and stem tissue. DNA sequence analyses of the Ceratocystis isolates, including multiple gene regions, identified the isolates as C. eucalypticola. Multiple ITS types were identified among the isolates sequenced, similar to those found in other, closely related, Ceratocystis species. Artificial inoculations under field conditions confirmed the pathogenicity of the isolates. This is the first report of a Ceratocystis sp. causing a wilt disease of Eucalyptus in South Africa. [ABSTRACT FROM AUTHOR]

• Study reveals MAT1 locus drives unidirectional mating-type switching in fungi. • Self-fertile isolates: MAT1-1 genes, MAT1-1-1 disrupted by MAT1-2. • Self-sterile isolates: Only MAT1-1 genes, recombination removes MAT1-2. • Commonalities: "Secondary" MAT1-1 genes are present in both arrangements. • Unidirectional switching may ensure reproductive assurance. Unidirectional mating-type switching is a form of homothallic reproduction known only in a small number of filamentous ascomycetes. Their ascospores can give rise to either self-sterile isolates that require compatible partners for subsequent sexual reproduction, or self-fertile individuals capable of completing this process in isolation. The limited studies previously conducted in these fungi suggest that the differences in mating specificity are determined by the architecture of the MAT1 locus. In self-fertile isolates that have not undergone unidirectional mating-type switching, the locus contains both MAT1-1 and MAT1-2 mating-type genes, typical of primary homothallism. In the self-sterile isolates produced after a switching event, the MAT1-2 genes are lacking from the locus, likely due to a recombination-mediated deletion of the MAT1-2 gene information. To determine whether these arrangements of the MAT1 locus support unidirectional mating-type switching in the Ceratocystidaceae , the largest known fungal assemblage capable of this reproduction strategy, a combination of genetic and genomic approaches were used. The MAT1 locus was annotated in representative species of Ceratocystis, Endoconidiophora, and Davidsoniella. In all cases, MAT1-2 genes interrupted the MAT1-1 – 1 gene in self-fertile isolates. The MAT1-2 genes were flanked by two copies of a direct repeat that accurately predicted the boundaries of the deletion event that would yield the MAT1 locus of self-sterile isolates. Although the relative position of the MAT1-2 gene region differed among species, it always disrupted the MAT1-1 – 1 gene and/or its expression in the self-fertile MAT1 locus. Following switching, this gene and/or its expression was restored in the self-sterile arrangement of the locus. This mirrors what has been reported in other species capable of unidirectional mating-type switching, providing the strongest support for a conserved MAT1 locus structure that is associated with this process. This study contributes to our understanding of the evolution of unidirectional mating-type switching. [ABSTRACT FROM AUTHOR]

Terpenes represent the biggest group of natural compounds on earth. This large class of organic hydrocarbons is distributed among all cellular organisms, including fungi. The different classes of terpenes produced by fungi are mono, sesqui, di- and triterpenes, although triterpene ergosterol is the main sterol identified in cell membranes of these organisms. The availability of genomic data from members in the Ceratocystidaceae enabled the detection and characterization of the genes encoding the enzymes in the mevalonate and ergosterol biosynthetic pathways. Using a bioinformatics approach, fungal orthologs of sterol biosynthesis genes in nine different species of the Ceratocystidaceae were identified. Ergosterol and some of the intermediates in the pathway were also detected in seven species (Ceratocystis manginecans, C. adiposa, Huntiella moniliformis, Thielaviopsis punctulata, Bretziella fagacearum, Endoconidiophora polonica and Davidsoniella virescens), using gas chromatography-mass spectrometry analysis. The average ergosterol content differed among different genera of Ceratocystidaceae. We also identified all possible terpene related genes and possible biosynthetic clusters in the genomes used in this study. We found a highly conserved terpene biosynthesis gene cluster containing some genes encoding ergosterol biosynthesis enzymes in the analysed genomes. An additional possible terpene gene cluster was also identified in all of the Ceratocystidaceae. We also evaluated the sensitivity of the Ceratocystidaceae to a triazole fungicide that inhibits ergosterol synthesis. The results showed that different members of this family behave differently when exposed to different concentrations of triazole tebuconazole.

Black root rot caused by the pathogen Thielaviopsis basicola has been known since the mid 1800s. The disease is important on many agricultural and ornamental plant species and has been found in at least 31 countries. Since its description, the pathogen has had a complex taxonomic history that has resulted in a confused literature. A recent revision of the Ceratocystidaceae following the advent of DNA sequencing technology has made it possible to resolve this confusion. Importantly, it has also shown that there are two pathogens in the Ceratocystidaceae that cause black root rot. They reside in the newly established genus Berkeleyomyces and are now known as B. basicola and B. rouxiae. This review considers the taxonomic history of the black root rot pathogens, and their global distribution. Prospects relating to the serious diseases that they cause and the likely impact that the era of genomics will have on our understanding of the pathogens are also highlighted. [ABSTRACT FROM AUTHOR]

The ascomycete genus Huntiella (Microascales) has a cosmopolitan distribution and occurs on a wide range of woody plants. Little is known regarding the identity, diversity, origin, or impact of these fungi in China. Recently, isolates of Huntiella spp. were collected from stumps of freshly felled trees or wounds on plantation-grown Eucalyptus in Guangdong, Guangxi, Fujian, and Hainan provinces of southern China. Additional isolates were obtained from stumps of Acacia confusa near Eucalyptus plantations in Hainan Province. The aim of this study was to identify these Huntiella species and to test their pathogenicity on Eucalyptus seedlings. Morphology and multigene phylogenies of the nuclear rDNA internal transcribed spacer (ITS1-5.8S-ITS2 = ITS) region and partial β-tubulin (BT1) and translation elongation factor 1α (TEF1α) genes revealed nine previously unknown Huntiella species, eight from Eucalyptus and one from A. confusa. The mating types of these species were determined, showing that seven are heterothallic, one is homothallic, and one is unisexual (MAT1-2-1 gene). Pathogenicity tests showed that the nine Huntiella species can produce lesions on Eucalyptus seedlings, larger than wounds caused by controls on these plants. This study provides a basic understanding of the distribution, diversity, and pathogenicity of Huntiella species in southern China. [ABSTRACT FROM AUTHOR]

The native 'ōhi'a lehua (Metrosideros polymorpha) has cultural, biological and ecological significance to Hawai'i, but it is seriously threatened by a disease commonly referred to as rapid 'ōhi'a death (ROD). Preliminary investigations showed that a Ceratocystis species similar to C. fimbriata s.lat. was the cause of the disease. In this study, we used a combination of the phylogenetic, morphological and biological species concepts, as well as pathogenicity tests and microsatellite analyses, to characterise isolates collected from diseased 'ōhi'a trees across Hawai'i Island. Two distinct lineages, representing new species of Ceratocystis, were evident based on multigene phylogenetic analyses. These are described here as C. lukuohia and C. huliohia. Ceratocystis lukuohia forms part of the Latin American clade (LAC) and was most closely associated with isolates from Syngonium and Xanthosoma from the Caribbean and elsewhere, including Hawai'i, and C. platani, which is native to eastern USA. Ceratocystis huliohia resides in the Asian-Australian clade (AAC) and is most closely related to C. uchidae, C. changhui and C. cercfabiensis, which are thought to be native to Asia. Morphology and interfertility tests support the delineation of these two new species and pathogenicity tests show that both species are aggressive pathogens on seedlings of M. polymorpha. Characterisation of isolates using microsatellite markers suggest that both species are clonal and likely represent recently-introduced strains. Intensive research is underway to develop rapid screening protocols for early detection of the pathogens and management strategies in an attempt to prevent the spread of the pathogens to the other islands of Hawai'i, which are currently disease free. [ABSTRACT FROM AUTHOR]

The ascomycete genus Ceratocystis has a broad geographic distribution and includes pathogens of a wide range of mostly woody hosts. Black rot of Colocasia esculenta (taro), a popular cultivated root crop in China, is caused by a species of Ceratocystis broadly treated as C. fimbriata sensu lato. Recently, isolates of Ceratocystis were obtained from black rot lesions on C. esculenta corms in two Chinese provinces. Sequence comparison of the ITS, partial β‐tubulin, TEF‐1α, MS204 and RPBII gene regions were used to identify these isolates and compare them to other Ceratocystis species. Furthermore, the diversity of Ceratocystis species in the Asian‐Australian clade (AAC) was investigated using 23 microsatellite markers. Results showed that the isolates from C. esculenta represent a novel species, which is morphologically and phylogenetically different to closely related species in the AAC, and is described here as Ceratocystis changhui sp. nov. In microsatellite analyses, this new species also emerged as distinct from others in the AAC. Inoculation tests showed that C. changhui sp. nov. is a virulent pathogen of C. esculenta corms, but produces only small lesions on Eucalyptus grandis and Eriobotrya japonica. [ABSTRACT FROM AUTHOR]

The African fungal tree pathogen, Ceratocystis albifundus, undergoes uni-directional mating type switching, giving rise to either self-fertile or self-sterile progeny. Self-sterile isolates lack the MAT1-2-1 gene and have reduced fitness such as slower growth and reduced pathogenicity, relative to self-fertile isolates. While it has been hypothesized that there is a 1:1 ratio of self-fertile to self-sterile ascospore progeny in relatives of C. albifundus , some studies have reported a significant bias in this ratio. This could be due to the fact that either fewer self-sterile ascospores are produced or that self-sterile ascospores have low viability. We quantified the percentage of self-sterile and self-fertile ascospores from ascospore masses in C. albifundus using real-time PCR. Primers were designed to distinguish between spores that contained the MAT1-2-1 gene and those where this gene had been deleted. A significant bias towards the self-fertile mating type was observed in all single ascospore masses taken from sexual structures produced in haploid-selfed cultures. The same result was observed from a disease outbreak situation in an intensively managed field of cultivated native trees, and this was coupled with very low population diversity in the pathogen. This was in contrast to the results obtained from ascospore masses taken from the crosses performed under laboratory conditions or ascomata on native trees in a non-disease situation, where either self-fertile or self-sterile ascospores were dominant. The results suggest that reproductive strategies play a significant role in the infection biology and genetic structure of C. albifundus populations. [ABSTRACT FROM AUTHOR]

The genomes of Cercospora zeina, Fusarium pininemorale, Hawksworthiomyces lignivorus, Huntiella decipiens, and Ophiostoma ips are presented in this genome announcement. Three of these genomes are from plant pathogens and otherwise economically important fungal species. Fusarium pininemorale and H. decipiens are not known to cause significant disease but are closely related to species of economic importance. The genome sizes range from 25.99 Mb in the case of O. ips to 4.82 Mb for H. lignivorus. These genomes include the first reports of a genome from the genus Hawksworthiomyces. The availability of these genome data will allow the resolution of longstanding questions regarding the taxonomy of these species. In addition these genome sequences through comparative studies with closely related organisms will increase our understanding of how these species or close relatives cause disease. [ABSTRACT FROM AUTHOR]

Vascular wilt in cocoa (MVC) caused by different species of the genus Ceratocystis spp is a lethal disease that causes the death of the tree. In Colombia, the species of the genus Ceratocystis spp associated with the disease are unknown. This research aimed to characterize 24 isolates of Ceratocystis spp. by morphology, physiology and at the molecular level. coming from producing regions of Huila, Santander, Tolima and Valle del Cauca. For morphological characterization, micrometric measurements of the diameter of the perithecium (DP), the length of the perithecium neck (LC) and the length/width ratio of the ascospores (RA) were made in 30 structures per isolation. At a physiological level, daily colony growth measurements were carried out on malt extract agar medium (MAA) at pH (5, 7 and 9). Molecular characterization was performed by sequencing nuclear DNA regions of four gene regions: internal transcribed spacer (ITS), betatubulin (β-tubulin), elongation factor (TEF) and beta subunit of binding protein guanine nucleotides (MS204). Morphological and physiological measurements were analyzed using ANOVA and Tukey (SAS program). A high phenotypic variability was determined between the isolates because they presented wide ranges in the size of the structures: DP (101.23 to 264.25 µm), LC (199.35 to 701.28 µm) and RA (1 to 2, 12 µm) (P<0.05). Ceratocystis adelpha, Ceratocitys fimbriata and Ceratocyistis cacaofunesta were the species identified associated with MVC. Neutral to basic pH conditions favored the growth of the fungus in AEM (P<0.05). As a preliminary management recommendation, it is suggested to avoid planting the crop in soils with basic pH. [ABSTRACT FROM AUTHOR]

Recent reclassification of the Ceratocystidaceae (Microascales) based on multi-gene phylogenetic inference has shown that the oak wilt fungus Ceratocystis fagacearum does not reside in any of the four genera in which it has previously been treated. In this study, we resolve typification problems for the fungus, confirm the synonymy of Chalara quercina (the first name applied to the fungus) and Endoconidiophora fagacearum (the name applied when the sexual state was discovered). Furthermore, the generic placement of the species was determined based on DNA sequences from authenticated isolates. The original specimens studied in both protologues and living isolates from the same host trees and geographical area were examined and shown to represent the same species. A lectotype was designated for Chalara quercina and Endoconidiophora fagacearum and an epitype linked to a living ex-epitype isolate was designated. Phylogenetic analyses confirmed that the species resides in a well-supported monophyletic lineage in the Ceratocystidaceae, distinct from all other genera in the family. The new genus Bretziella is described to accommodate the oak wilt fungus. [ABSTRACT FROM AUTHOR]

Genera of ambrosia beetles in the tribe Xyleborini with large, mesonotal mycangia host unique fungal symbionts in the genus Ambrosiella. The symbiont of a recent invasive to the USA from Asia, Anisandrus maiche Stark, had not been previously characterized. We found the mycangium anatomy of An. maiche collected in Ohio to be similar to that of Anisandrus dispar and consistently isolated a novel fungus, Ambrosiella cleistominuta sp. nov., from An. maiche mycangia and galleries. The fungus was distinguished from other named Ambrosiella by morphological characters and DNA sequences (ITS rDNA and tef-1α). The mycangial symbionts of ambrosia beetles had been assumed to be strictly asexual, but A. cleistominuta produces cleistothecious ascomata with ascospores in beetle galleries and in culture. In contrast to ascomata of other Ceratocystidaceae, the relatively small ascomata of A. cleistominuta are neckless and without ostioles. The ascospores are relatively large, and single-ascospore colonies produced ascomata and ascospores in culture, showing that A. cleistominuta is homothallic. [ABSTRACT FROM AUTHOR]

Ceratocystis tsitsikammensis was first isolated from bark harvesting wounds on two indigenous tree species in the Afromontane forests of the Western Cape Province of South Africa. Inoculation studies indicated that it is a potential pathogen of native Rapanea melanophloeos trees. In this study, we investigated the distribution, ecology and biology of C. tsitsikammensis in the Garden Route National Park of South Africa. Isolates were obtained from wounds on R. melanophloeos, three non-native hosts as well as from nitidulid and staphylinid beetles visiting wounds on these trees. The genetic diversity and population biology of the fungus was examined using microsatellite markers. Its mating strategy was also determined by amplifying its mating type genes and the fungus was shown to be homothallic. Despite the homothallic nature of the fungus, high levels of random mating and absence of genetic structure was found in the investigated population, suggesting a strong effect of gene flow, probably linked to insect dispersal. The gene diversity of C. tsitsikammensis was similar to that of a related fungus, Ceratocystis albifundus , that is known to be native in Africa. This, together with the fact that C. tsitiskamensis is not known elsewhere, within or outside South Africa, suggests that it is native and endemic to the Cape Afromontane region. [ABSTRACT FROM AUTHOR]

Little is known about the biology of the monotypic genus Cornuvesica ( Microascales ), apart from that isolates are notoriously difficult to culture on artificial media. A recent collection of material resembling this genus from freshly made wounds on Gmelina arborea in Indonesia, provided an opportunity to reconsider all available material of Cornuvesica falcata , type species of the genus. In addition to morphological comparisons, multigene phylogenetic analyses were made using sequences of the SSU, ITS, LSU and TEF-1α genes. Our results showed that the holotype of Cor. falcata from pine in Canada differed from all other material previously considered to represent this species and also from the new Indonesian collections. The collections considered represented three additional species that we describe here as new. Three New Zealand isolates and an isolate from UK were respectively described as Cor. acuminata and Cor. crypta , while the Indonesian isolates were described as Cor. magnispora . Phylogenies based on the SSU and LSU data sets showed that Cornuvesica spp. do not belong in the Ceratocystidaceae as previously suggested, but represent a distinct lineage in the Microascales that has yet to be named. Results showed that culture filtrates from other fungi or ferric chloride markedly stimulated the growth of Cor. magnispora . [ABSTRACT FROM AUTHOR]

During routine surveys for possible fungal pathogens in the rapidly expanding plantations of Eucalyptus and Cunninghamia lanceolata in China, numerous isolates of unknown species in the genus Ceratocystis (Microascales) were obtained from tree wounds. In this study we identified the Ceratocystis isolates from Eucalyptus and Cunninghamia in the GuangDong, GuangXi, FuJian and HaiNan Provinces of South China based on morphology and through comparisons of DNA sequence data for the ITS, partial β-tubulin and TEF-1α gene regions. Morphological and DNA sequence comparisons revealed two previously unknown species residing in the Indo-Pacific Clade. These are described here as Ceratocystis cercfabiensis sp. nov. and Ceratocystis collisensis sp. nov. Isolates of Ceratocystis cercfabiensis showed intragenomic variation in their ITS sequences and four strains were selected for cloning of the ITS gene region. Twelve ITS haplotypes were obtained from 17 clones selected for sequencing, differing in up to seven base positions and representing two separate phylogenetic groups. This is the first evidence of multiple ITS types in isolates of Ceratocystis residing in the Indo-Pacific Clade. Caution should thus be exercised when using the ITS gene region as a barcoding marker for Ceratocystis species in this clade. This study also represents the first record of a species of Ceratocystis from Cunninghamia. [ABSTRACT FROM AUTHOR]

The Ceratocystis paradoxa complex accommodates a group of fungal pathogens that have become specialized to infect mostly monocotyledonous plants. Four species currently are recognized in this group, including C. paradoxa, which has a widespread distribution and broad host range. In this study, multigene phylogenetic analyses involving sequences of the ITS, β-tubulin and TEF-1α gene loci, in combination with phenotypic and mating studies, were used to characterize purported C. paradoxa isolates from Cameroon and to compare them with isolates from elsewhere, including proto-logs and type specimens of known species. We show that the C. paradoxa complex comprises substantially greater species diversity than previously recognized. One new species in this group is described from Cameroon as Ceratocystis cerberus, while C. paradoxa sensu stricto (s. str.) and four other species are redefined. Lectotypes are designated for C. ethacetica and Endoconidium fragrans (synonym of C. ethacetica), while epitypes are designated for C. paradoxa s. str., C. ethacetica and C. musarum. A neotype is designated for Catenularia echinata (synonym of C. ethacetica) and two species, previously treated in Thielaviopsis, are transferred to Ceratocystis. [ABSTRACT FROM AUTHOR]

Commercial plantations of Eucalyptus species have been established in South China, especially during the past 20 years, to meet the needs of a rapidly growing national economy. As part of a survey of fungal diseases affecting Eucalyptus species in South China, Ceratocystis species were collected from Eucalyptus plantations in the GuangDong Province. The aims of this study were to identify these Ceratocystis isolates and to test their pathogenicity to Eucalyptus. The most aggressive isolates were also used to screen different species and clones of Eucalyptus for susceptibility to infection under field conditions. The fungi were identified based on morphology and through comparisons of DNA sequence data of the ITS, partial β-tubulin and TEF-1α gene regions. Morphological and DNA sequence comparisons showed that isolates collected from Chinese Eucalyptus plantations represent two species, C. acaciivora in the C. fimbriata s. l. species complex and a previously undescribed species belonging to the C. moniliformis s. l. species complex, for which the name C. chinaeucensis sp. nov. is provided. In pathogenicity trials, both C. acaciivora and C. chinaeucensis gave rise to lesions on wounded Eucalyptus trees, and the former fungus was most pathogenic. Differences were also observed in the responses of different Eucalyptus clones to inoculation and this could be useful in reducing disease, if C. acaciivora should emerge as a pathogen in the future. [ABSTRACT FROM AUTHOR]