Multigene phylogenetic and population differentiation data confirm the existence of a cryptic species within Chrysoporthe cubensis

Chrysoporthe cubensis is one of the most important pathogens of Eucalyptus. Based on phylogenetic evidence and geographic origin, isolates of this fungus are known to reside in distinct 'South America' and 'Southeast Asia' clades. In this study, reproductive isolation amongst these isolates of C. cubensis was tested using gene flow statistics for 12 polymorphic loci, and to support these data, phylogenetic affiliations based on gene trees and a multigene phylogeny were used. Gene flow statistics between populations, and relative to the closely related Chrysoporthe austroafricana, were low and not significantly different (P<0.05). Additionally, phylogenetic analyses of DNA sequence data for four gene regions convincingly distinguished the two subclades of C. cubensis. Isolates in the Southeast Asian subclade are described in the new species, Chrysoporthe deuterocubensis. Chrysoporthe cubensis and C. deuterocubensis represent closely related fungi that are thought to be native to South America and Southeast Asia, respectively. A technique is presented that allows for rapid differentiation between these species and that will aid in quarantine procedures to limit their spread to new environments.     

New records of the Cryphonectriaceae from southern Africa including Latruncellus aurorae gen. sp. nov

The Cryphonectriaceae accommodates some of the world's most important tree pathogens, including four genera known from native and introduced Myrtales in Africa. Surveys in the past 3 y in southern Africa have led to the discovery of cankers with fruiting structures resembling those of the Cryphonectriaceae on trees in the Myrtales in Namibia, South Africa, Swaziland and Zambia. These fungi were identified with morphological characteristics and DNA sequence data. For the first time we report Chrysoporthe austroafricana from Namibia and on Syzygium guineense and Holocryphia eucalypti in Swaziland on a Eucalyptus grandis clone. The host and geographic ranges of Celoporthe dispersa are expanded to include S. legatti in South Africa and S. guineense in Zambia. In addition a monotypic genus, Latruncellus aurorae gen. sp. nov., is described from Galpinia transvaalica (Lythraceae, Myrtales) in Swaziland. The present and other recent studies clearly emphasize the limited understanding of the diversity and distribution of fungi in the Cryphonectriaceae in Africa.     

Novel hosts of the Eucalyptus canker pathogen Chrysoporthe cubensis and a new Chrysoporthe species from Colombia

The pathogen Chrysoporthe cubensis (formerly Cryphonectria cubensis) is best known for the important canker disease that it causes on Eucalyptus species. This fungus is also a pathogen of Syzygium aromaticum (clove), which is native to Indonesia, and like Eucalyptus, is a member of Myrtaceae. Furthermore, C. cubensis has been found on Miconia spp. native to South America and residing in Melastomataceae. Recent surveys have yielded C. cubensis isolates from new hosts, characterized in this study based on DNA sequences for the ITS and β-tubulin gene regions. These hosts include native Clidemia sericea and Rhynchanthera mexicana (Melastomataceae) in Mexico, and non-native Lagerstroemia indica (Pride of India, Lythraceae) in Cuba. Isolates from these hosts and areas group in the sub-clade of C. cubensis accommodating the South American collections of the fungus. This sub-clade also includes isolates recently collected from Eucalyptus in Cuba, which are used to epitypify C. cubensis. New host records from Southeast Asia include exotic Tibouchina urvilleana from Singapore and Thailand and native Melastoma malabathricum (Melastomataceae) in Sumatra, Indonesia. Consistent with their areas of occurrence isolates from the latter collections group in the Asian sub-clade of C. cubensis. DNA sequence comparisons of isolates from Tibouchina lepidota in Colombia revealed that they represent a new sub-clade within the greater Chrysoporthe clade. Isolates in this clade are described as Chrysoporthe inopina sp. nov., based on distinctive morphological differences.     

Genetic control of Eucalyptus urophylla and E. grandis resistance to canker caused by Chrysoporthe cubensis

Chrysophorte cubensis induced canker occurs in nearly all tropical and subtropical regions where eucalypts are planted, causing losses in both wood quality and volume productivity, especially so in the warmer and more humid regions of Brazil. The wide inter and intra-specific genetic variability of resistance to canker among Eucalyptus species facilitates the selection of resistant plants. In this study, we evaluated resistance to this pathogen in five Eucalyptus grandis (G) and 15 E. urophylla (U) trees, as well as in 495 individuals from 27 progenies derived from crosses between the trees. In the field, six-months-old test seedlings were inoculated with C. cubensis. Lesion length in the xylem and bark was measured eight months later. The results demonstrated that xylem lesions could preferentially be used for the selection of resistant clones. Eight trees (7 U and 1 G) were susceptible, and the remainder (8 U and 4 G) resistant. Individual narrow and broad sense heritability estimates were 17 and 81%, respectively, thereby suggesting that canker resistance is quantitative and highly dependent on dominance and epistasis.     

Ceratocystis pirilliformis, a new species from Eucalyptus nitens in Australia

Several species of Ceratocystis have been recorded on Eucalyptus. These include C. fimbriata, C. eucalypti, C. moniliformis and C. moniliformopsis. Of these, only C. fimbriata is known as a pathogen; it recently has been found causing serious wilt diseases in Uganda, Congo and Brazil. This study was undertaken to collect Ceratocystis species, including C. eucalypti, from artificially induced wounds on Eucalyptus nitens near Canberra in southeastern Australia. Trees were wounded in October 2000, and wounds were examined approximately one month later. Ascomata characteristic of a Ceratocystis species were found covering the wounds, and this fungus also was isolated from the wood using carrot baiting. This species of Ceratocystis has hat-shaped ascospores similar to those of C. fimbriata, but it differs from C. fimbriata and all other species of Ceratocystis in that it possesses ascomata with a pyriform base. Comparison of DNA sequences from the ITS and 5.8S rRNA operon confirmed that the fungus from E. nitens in Australia is unique, and we describe it here as a new species, C. pirilliformis.     

Ophiostoma breviusculum sp. nov. (Ophiostomatales, Ascomycota) is a new species in the Ophiostoma piceae complex associated with bark beetles infesting larch in Japan

A new species of the Ophiostoma piceae-complex was isolated from bark beetles and the insect galleries of Larix kaempferi in Japan. This species was described as Ophiostoma breviusculum. The fungus was morphologically similar to O. piceae and O. quercus. However the average length of the perithecial necks and synnemata were shorter than for O. piceae and O. quercus. Synnemata morphological characteristics also differentiated O. breviusculum from the other species of the Ophiostoma piceae-complex isolated from conifers. Mating tests demonstrated that this fungus did not produce perithecia with O. floccosum, O. piceae and O. quercus. In phylogenetic trees using rDNA ITS O. breviusculum was placed in a clade with O. canum, O. piceae and O. subalpinum, but when using beta-tubulin it was placed into a separate clade.     

Novel species of Celoporthe from Eucalyptus and Syzygium trees in China and Indonesia

Many species in the Cryphonectriaceae cause diseases of trees, including those in the genera Eucalyptus and Syzygium. During disease surveys on these trees in southern China, fruiting structures typical of fungi in the Cryphonectriaceae and associated with dying branches and stems were observed. Morphological comparisons suggested that these fungi were distinct from the well known Chrysoporthe deuterocubensis, also found on these trees in China. The aim of this study was to identify these fungi and evaluate their pathogenicity to Eucalyptus clones/species as well as Syzygium cumini. Three morphologically similar fungal isolates collected previously from Indonesia also were included in the study. Isolates were characterized based on comparisons of morphology and DNA sequence data for the partial LSU and ITS nuclear ribosomal DNA, β-tubulin and TEF-1α gene regions. After glasshouse trials to select virulent isolates field inoculations were undertaken to screen different commercial Eucalyptus clones/species and S. cumini trees for susceptibility to infection. Phylogenetic analyses showed that the Chinese isolates and those from Indonesia reside in a clade close to previously identified South African Celoporthe isolates. Based on morphology and DNA sequence comparisons, four new Celoporthe spp. were identified and they are described as C. syzygii, C. eucalypti, C. guangdongensis and C. indonesiensis. Field inoculations indicated that the three Chinese Celoporthe spp., C. syzygii, C. eucalypti and C. guangdongensis, are pathogenic to all tested Eucalyptus and S. cumini trees. Significant differences in the susceptibility of the inoculated Eucalyptus clones/species suggest that it will be possible to select disease-tolerant planting stock for forestry operations in the future.     

Fungal Infection of Mantis Shrimp (<Emphasis Type="Italic">Oratosquilla oratoria</Emphasis>) Caused by Two Anamorphic Fungi Found in Japan

Two fungal pathogens of the mantis shrimp (Oratosquilla oratoria) in Yamaguchi and Aichi Prefectures, Japan are described as the new species Plectosporium oratosquillae and Acremonium sp. (a member of the Emericellopsis marine clade). Both fungi infect the gills of the mantis shrimp, which become brown or black due to melanization. The former species is characterized by its slow growth on artificial seawater yeast extract peptone glucose (PYGS) agar, pale yellow to pale orange or grayish yellow colonies, short cylindrical solitary phialides with a wavy tip, and one-celled ellipsoidal conidia. Although lacking the two-celled conidia demonstrated by the type species Plectosporium tabacinum, the taxonomic placement of the new species was confirmed by DNA sequence analysis of the internal transcribed spacer (ITS) region of ribosomal DNA (ITS1, 5.8S rDNA and ITS2). Acremonium sp., the other causal pathogen, differs from P. oratosquillae by its fast growth on PYGS agar, pale orange to salmon-colored colonies, long, slender conidiophores consisting of solitary phialides with tips lacking an undulate outline, and typically cylindrical conidia. Analysis of ITS and β-tubulin gene sequences placed this fungus within the phylogenetically distinct Emericellopsis (anam. Acremonium) marine clade. Various physiological characteristics of both pathogens were also investigated. This is the first report of a fungal infection found on the mantis shrimp in Japan.     

Phylogenetic analyses of Septoria species based on the ITS and LSU-D2 regions of nuclear ribosomal DNA

The phylogenetic relationships of 17 selected Septoria spp. (eight with a known Mycosphaerella teleomorph), Phloeospora ulmi (teleomorph M. ulmi) and 18 additional taxa (10 with a Mycosphaerella teleomorph) were inferred from ITS and D2-LSU nrDNA sequences. In total, 10 anamorph genera associated with Mycosphaerella were represented. Intraspecific variation in ITS was limited in Septoria, with the exception of three strains that all were identified as S. rubi but originated from different Rubus spp. and probably belong to different species of Septoria. The results of D2 region sequencing confirmed Mycosphaerella sense lato (including Davidiella and Eruptio) as monophyletic. The cereal pathogen Septoria tritici, which is closely related to S. passerinii as found in ITS analysis, clusters with Ramularia spp. in the D2 analyses, distant from the other Septoria spp. The pathogens S. apiicola, S. linicola and S. populicola cluster in a major clade containing Phl. ulmi, and other Septoria spp. and Cercospora spp. Short branch lengths in this clade suggest a very recent evolution. Septoria castaneicola and S. pyricola also might represent relatively distant lineages. Both analyses of the regions indicated that Septoria is not monophyletic within Mycosphaerella and that conidiomatal structure (acervulus, pycnidium) has little value for predicting phylogenetic relatedness. As a consequence, the separation between the acervular Phloeospora and pycnidial Septoria is untenable. The loss of the teleomorph most likely has occurred several times in the evolutionary history of Mycosphaerella.     

Puccinia psidii infecting cultivated Eucalyptus and native myrtaceae in Uruguay

Eucalyptus or guava rust caused by Puccinia psidii is a serious disease of Eucalyptus and other Myrtaceae. In Uruguay, it has been previously found on Eucalyptus globulus and Psidium brasiliensis. Almost nothing is known regarding the occurrence of this pathogen on other Eucalyptus species or native Myrtaceae in that country. In this study, we determined the presence of P. psidii on Eucalyptus species and native Myrtaceae trees in Uruguay and evaluated the pathogenicity of specimens from native myrtaceous hosts on E. globulus and E. grandis. Phylogenetic analyses based on the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA operon were used to confirm pathogen identity. Comparisons of ITS sequences confirmed the identity of P. psidii on Eucalyptus globulus, E. grandis, Myrcianthes pungens, and Myrrhinium atropurpureum var. octandrum. This is the first report of P. psidii on M. atropurpureum var. octandrum. Pathogenicity tests showed that isolates from native Myrtaceae could infect both Eucalyptus species tested, indicating a strong biological relationship between both introduced and native Myrtaceae. This study supplies relevant field data, morphological information, molecular phylogenetic analyses and infection studies that contribute to a better understanding of an important and little studied pathogen.     

Colletotrichum gigasporum sp. nov., a new species of Colletotrichum producing long straight conidia

A new species of Colletotrichum was described, based on morphology and phylogeny. The fungus was isolated in Madagascar from healthy leaves of Centella asiatica, in Mexico from wild native of Stylosanthes guianensis and in Colombia from Coffea arabica. The fungus differed from the currently related species in the genus by its longer and wider size of conidia. In potato dextrose agar medium supplemented with sterilized leaf powder of Ce. asiatica, the fungus produced fertile perithecia containing asci and unusual long ascospores measuring up to 90 μm. In addition to these morphological characteristics, the maximum parsimony analysis of the ITS region and β-tubulin gene placed the fungus in a distinct clade far from the currently valid Colletotrichum species. Based on the morphological and molecular characterization, Colletotrichum gigasporum sp. nov. was proposed as a new species in the genus Colletotrichum Corda.     

Phylogenetic relationships of Cryphonectria and Endothia species, based on DNA sequence data and morphology

The fungal genera Endothia and Cryphonectria include some of the most important pathogens of forest trees. Despite available new technology, no comprehensive comparative study based on DNA sequence data and morphology has been done on the available isolates representing these two genera. The main objectives of this study were to assess the phylogenetic relationships among species of Cryphonectria and Endothia, for which cultures are available, and to establish a taxonomic framework based on DNA sequence and morphological data, which will aid future studies and identification of species in these and related genera. Comparisons were based on sequence variation found in the ITS region of the ribosomal RNA operon and two regions of the β-tu-bulin gene. In addition, the morphology of these species was examined. The phylogenetic data indicated that Endothia and Cryphonectria reside in two distinct phylogenetic clades. Cryphonectria parasitica, C. macrospora, C. nitschkei, C. eucalypti and C. radicalis represented the Cryphonectria clade. Endothia gyrosa and E. singularis were included in the Endothia clade. An isolate representing E. viridistroma grouped outside the Endothia clade and separately from other groups. Other clades outside the one encompassing Cryphonectria were those represented by the C. cubensis isolates and fungi isolated from Elaeocarpus dentatus originating from New Zealand. These clades could be distinguished from Endothia and Cryphonectria, based on anamorph morphology, stromatal structure and ascospore septation. Cryphonectria and Endothia, therefore, appear to be paraphyletic and taxonomic relationships for these fungi need to be revised.     

基于叶绿体基因组探讨桃金娘目及其近缘类群的系统发育关系

该研究基于叶绿体基因组数据,对桃金娘目(6科44属97种)及其近缘类群(牻牛儿苗目2科5属25种)的系统发育关系进行了分析.结果表明:(1)桃金娘目基因组大小为152～171 kb,包括的蛋白质编码基因数目为74～90个;牻牛儿苗目基因组大小为116～242 kb,包括的蛋白质编码基因数目为75～132个.(2)对比叶...     

ITS sequence data resolve higher level relationships among the eucalypts.

Sequences of the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA were obtained for 35 species of Eucalyptus s.s. and seven taxa representing five outgroup genera (Allosyncarpia, Angophora, Arillastrum, Corymbia, and Stockwellia). The sequences were analyzed cladistically. The data distinguished clearly between the two major subgenera of Eucalyptus s.s. (Symphyomyrtus and Monocalyptus) but indicated that subgenus Eudesmia may be paraphyletic. ITS sequence data demonstrated the potential to resolve relationships between sections within subgenus Symphyomyrtus. Within sections, however, taxa were poorly differentiated. At the generic level, Corymbia appeared to be paraphyletic due to the exclusion of Angophora. The positions of Allosyncarpia and Arillastrum relative to the ingroup remain unresolved. ITS sequence data may prove valuable for resolving other phylogenetic relationships at higher taxonomic levels within Eucalyptus.     

Multilocus phylogenetic analyses within Blumeria graminis, a powdery mildew fungus of cereals

Blumeria graminis, a powdery mildew fungus, is an important plant pathogen that causes serious damage to a variety of cereal crops. In spite of the importance of the pathogen, information on phylogenetic structure within B. graminis is scarce. In this study we conducted phylogenetic analyses of B. graminis based on the DNA sequences of four different DNA regions (ITS, 28S rDNA, chitin synthase 1, and beta-tubulin). The analyses revealed that the protein-coding regions have higher amounts of phylogenetic signals than rDNA regions and are useful for phylogenetic analyses of B. graminis. The present phylogenetic analyses revealed nine distinct groups in the B. graminis isolates used in this study, a result which was commonly supported by all trees constructed from the four DNA regions. Isolates from a single host genus belonged to a single group except for isolates from Lolium and Bromus, in which the isolates were split into two and three groups, respectively. Isolates from Agropyron, Secale and Triticum formed a distinct clade (Triticum clade) with identical or similar DNA sequences. The Hordeum clade was a sister of the Triticum clade, and Poa and Avena clades were distantly related to the Triticum and Hordeum clades. This phylogenetic relationship of B. graminis is well concordant with the level of reproductive isolation between formae speciales and also with phylogeny inferred from a cytological study. Shimodaira-Hasegawa and Templeton tests using sequences of four different DNA regions significantly rejected the tree topology of plants. Therefore, possibility of co-speciation between B. graminis and its host plants was obscure in this study.     

Morphological and molecular characterization of Phomopsis vaccinii and additional isolates of Phomopsis from blueberry and cranberry in the eastern United States

Forty isolates of Phomopsis were obtained from twigs and berries of highbush blueberry, Vaccinium corymbosum, and cranberry, Vaccinium macrocarpon, isolated primarily from plants grown in the eastern United States. They were characterized using conidiomatal morphology, conidial dimensions, colony appearance and growth rate, and sequences of ITS rDNA. Based on morphological and molecular similarities, most isolates grouped together with an authentic culture of Phomopsis vaccinii Shear. This taxon is described and illustrated. However, some Phomopsis isolates from Vaccinium differed in colony and conidiomatal morphology from P. vaccinii and, based on ITS sequences, were related to isolates of Phomopsis from diverse hosts. These isolates were excluded from P. vaccinii.     

Sequence analysis of the ribosomal DNA internal transcribed spacer 2 from populations of Anopheles nuneztovari (Diptera: Culicidae)

Sequence variation of the ribosomal DNA internal transcribed spacer 2 (ITS2) was examined for populations of the malaria vector Anopheles nuneztovari collected in Colombia, Venezuela, Bolivia, Suriname, and Brazil. Mosquitoes from Colombia and Venezuela had identical ITS2 sequences and were distinguished from sequences in other populations by three insertion/deletion events (indels) and by one transversion. The length of the ITS2 was 363-369 bp, and it had a G+C content of 55.3%- 55.7%. Variation in the length of the ITS2 between and within populations was due to indels in simple repeats. ITS2 consensus sequences were similar or identical for samples from the following three groups: (1) Colombia, Bolivia, and Venezuela; (2) Suriname and northern Brazil; and (3) eastern and central Brazil. The presence of two different consensus sequences from a single location near Manaus, Brazil, suggests that populations from eastern Brazil and those from Suriname converge in this region of the Amazon Basin. These data show that putative cryptic species of An. nuneztovari are distinguished by very minor differences in DNA sequence of the ITS2 region.      

Trichoderma amazonicum, a new endophytic species on Hevea brasiliensis and H. guianensis from the Amazon basin

A new species of Trichoderma (teleomorph Hypocrea, Ascomycota, Sordariomycetes, Hypocreales, Hypocreaceae), T. amazonicum, endophytic on the living sapwood and leaves of Hevea spp. trees is described. Trichoderma amazonicum is distinguished from closely related species in the Harzianum clade (e.g. Hypocrea alni, H. brunneoviridis, H. epimyces, H. parepimyces, T. aggressivum, T. harzianum, T. pleuroticola and T. pleuroti) by morphological and ecological characteristics and phylogenetic analysis of three loci (ITS nrDNA, tef1 and rpb2). The closest relatives of this species are the facultatively fungicolous species T. pleuroticola and T. pleuroti.     

<Emphasis Type="Italic">Aurifilum,</Emphasis> a new fungal genus in the Cryphonectriaceae from <Emphasis Type="Italic">Terminalia</Emphasis> species in Cameroon

Native Terminalia spp. in West Africa provide a popular source of construction timber as well as medical, spiritual and social benefits to rural populations. Very little is, however, known regarding the diseases that affect these trees. During an investigation into possible diseases of Terminalia spp. in Cameroon, orange to yellow fungal fruiting structures, resembling those of fungi in the Cryphonectriaceae, were commonly observed on the bark of native Terminalia ivorensis, and on dead branches of non-native Terminalia mantaly. In this study the fungus was identified based on morphological features as well as DNA sequence data (ITS and β-tubulin) and its pathogenicity was tested on T. mantaly seedlings. Our results showed that isolates of this fungus represent a previously undescribed genus in the Cryphonectriaceae, which we describe as Aurifilum marmelostoma gen. et sp. nov. Pathogenicity tests revealed that A. marmelostoma is pathogenic on T. mantaly. These tests, and the association of A. marmelostoma with disease symptoms on T. ivorensis, suggest that the fungus is a pathogen of this important tree.