Fungal Planet description sheets: 868-950.

Novel species of fungi described in this study include those from various countries as follows: Australia, Chaetomella pseudocircinoseta and Coniella pseudodiospyri on Eucalyptus microcorys leaves, Cladophialophora eucalypti, Teratosphaeria dunnii and Vermiculariopsiella dunnii on Eucalyptus dunnii leaves, Cylindrium grande and Hypsotheca eucalyptorum on Eucalyptus grandis leaves, Elsinoe salignae on Eucalyptus saligna leaves, Marasmius lebeliae on litter of regenerating subtropical rainforest, Phialoseptomonium eucalypti (incl. Phialoseptomonium gen. nov.) on Eucalyptus grandis × camaldulensis leaves, Phlogicylindrium pawpawense on Eucalyptus tereticornis leaves, Phyllosticta longicauda as an endophyte from healthy Eustrephus latifolius leaves, Pseudosydowia eucalyptorum on Eucalyptus sp. leaves, Saitozyma wallum on Banksia aemula leaves, Teratosphaeria henryi on Corymbia henryi leaves. Brazil, Aspergillus bezerrae, Backusella azygospora, Mariannaea terricola and Talaromyces pernambucoensis from soil, Calonectria matogrossensis on Eucalyptus urophylla leaves, Calvatia brasiliensis on soil, Carcinomyces nordestinensis on Bromelia antiacantha leaves, Dendryphiella stromaticola on small branches of an unidentified plant, Nigrospora brasiliensis on Nopalea cochenillifera leaves, Penicillium alagoense as a leaf endophyte on a Miconia sp., Podosordaria nigrobrunnea on dung, Spegazzinia bromeliacearum as a leaf endophyte on Tilandsia catimbauensis, Xylobolus brasiliensis on decaying wood. Bulgaria, Kazachstania molopis from the gut of the beetle Molops piceus. Croatia, Mollisia endocrystallina from a fallen decorticated Picea abies tree trunk. Ecuador, Hygrocybe rodomaculata on soil. Hungary, Alfoldia vorosii (incl. Alfoldia gen. nov.) from Juniperus communis roots, Kiskunsagia ubrizsyi (incl. Kiskunsagia gen. nov.) from Fumana procumbens roots. India, Aureobasidium tremulum as laboratory contaminant, Leucosporidium himalayensis and Naganishia indica from windblown dust on glaciers. Italy, Neodevriesia cycadicola on Cycas sp. leaves, Pseudocercospora pseudomyrticola on Myrtus communis leaves, Ramularia pistaciae on Pistacia lentiscus leaves, Neognomoniopsis quercina (incl. Neognomoniopsis gen. nov.) on Quercus ilex leaves. Japan, Diaporthe fructicola on Passiflora edulis × P. edulis f. flavicarpa fruit, Entoloma nipponicum on leaf litter in a mixed Cryptomeria japonica and Acer spp. forest. Macedonia, Astraeus macedonicus on soil. Malaysia, Fusicladium eucalyptigenum on Eucalyptus sp. twigs, Neoacrodontiella eucalypti (incl. Neoacrodontiella gen. nov.) on Eucalyptus urophylla leaves. Mozambique, Meliola gorongosensis on dead Philenoptera violacea leaflets. Nepal, Coniochaeta dendrobiicola from Dendriobium lognicornu roots. New Zealand, Neodevriesia sexualis and Thozetella neonivea on Archontophoenix cunninghamiana leaves. Norway, Calophoma sandfjordenica from a piece of board on a rocky shoreline, Clavaria parvispora on soil, Didymella finnmarkica from a piece of Pinus sylvestris driftwood. Poland, Sugiyamaella trypani from soil. Portugal, Colletotrichum feijoicola from Acca sellowiana. Russia, Crepidotus tobolensis on Populus tremula debris, Entoloma ekaterinae, Entoloma erhardii and Suillus gastroflavus on soil, Nakazawaea ambrosiae from the galleries of Ips typographus under the bark of Picea abies. Slovenia, Pluteus ludwigii on twigs of broadleaved trees. South Africa, Anungitiomyces stellenboschiensis (incl. Anungitiomyces gen. nov.) and Niesslia stellenboschiana on Eucalyptus sp. leaves, Beltraniella pseudoportoricensis on Podocarpus falcatus leaf litter, Corynespora encephalarti on Encephalartos sp. leaves, Cytospora pavettae on Pavetta revoluta leaves, Helminthosporium erythrinicola on Erythrina humeana leaves, Helminthosporium syzygii on a Syzygium sp. bark canker, Libertasomyces aloeticus on Aloe sp. leaves, Penicillium lunae from Musa sp. fruit, Phyllosticta lauridiae on Lauridia tetragona leaves, Pseudotruncatella bolusanthi (incl. Pseudotruncatellaceae fam. nov.) and Dactylella bolusanthi on Bolusanthus speciosus leaves. Spain, Apenidiella foetida on submerged plant debris, Inocybe grammatoides on Quercus ilex subsp. ilex forest humus, Ossicaulis salomii on soil, Phialemonium guarroi from soil. Thailand, Pantospora chromolaenae on Chromolaena odorata leaves. Ukraine, Cadophora helianthi from Helianthus annuus stems. USA, Boletus pseudopinophilus on soil under slash pine, Botryotrichum foricae, Penicillium americanum and Penicillium minnesotense from air. Vietnam, Lycoperdon vietnamense on soil. Morphological and culture characteristics are supported by DNA barcodes.

The forgotten Calonectria collection: Pouring old wine into new bags.

The genus Calonectria with its Cylindrocladium asexual morphs has been subject to several taxonomic revisions in the past. These have resulted in the recognition of 116 species, of which all but two species (C. hederae and C. pyrochroa) are supported by ex-type cultures and supplemented with DNA barcodes. The present study is based on a large collection of unidentified Calonectria isolates that have been collected over a period of 20 years from various substrates worldwide, which has remained unstudied in the basement of the CBS-KNAW Fungal Biodiversity Centre. Employing a polyphasic approach, the identities of these isolates were resolved and shown to represent many new phylogenetic species. Of these, 24 are newly described, while C. uniseptata is reinstated at species level. We now recognise 141 species that include some of the most important plant pathogens globally.

Diversity and potential impact of Calonectria species in Eucalyptus plantations in Brazil.

Species in the genus Calonectria (Hypocreales) represent an important group of plant pathogenic fungi that cause serious losses to plant crops in tropical and subtropical climates. Calonectria leaf blight is currently one of the main impediments to Eucalyptus cultivation in Brazil, and various species of Calonectria have been associated with this disease. Since most previous identifications were solely based on morphological characters, much of the published literature needs to be re-evaluated. The aim of this study was thus to identify and determine the phylogenetic relationships among species that occur in the Eucalyptus growing regions of Brazil by using partial sequences of the ß-tubulin, calmodulin, translation elongation factor 1-α and histone H3 gene regions. Based on extensive collections from soil and infected eucalypt leaf samples from plantations, phylogenetic inference revealed the Ca. pteridis complex to be the most common species complex present in Eucalyptus plantations in Brazil. By elucidating taxa in the Ca. pteridis, Ca. cylindrospora and Ca. candelabra species complexes, 20 novel Calonectria species were identified, and a new name in Calonectria provided for Cylindrocladium macrosporum as Ca. pseudopteridis.

Ceratocystis tiliae sp. nov., a wound pathogen on Tilia americana.

Species in the North American clade (NAC) of the Ceratocystis fimbriata complex are mostly weak pathogens that infect native tree hosts through fresh wounds. Isolations from discolored tissue of wounded Tilia americana (basswood) in Iowa and Nebraska yielded a Ceratocystis species that was similar to but distinct from isolates of C. variospora from other hosts. Sequences of 28S rDNA showed that isolates from basswood did not differ from C. variospora, but there were minor differences in ITS rDNA sequences. The DNA sequences of a portion of the Cerato-platanin gene and TEF1α showed the basswood fungus to be a unique lineage. Cross inoculations in two experiments showed that the basswood isolates and C. variospora isolates from Quercus spp. were most aggressive to their respective hosts. Isolates from basswood grew slower and were less pigmented than C. variospora isolates from Quercus spp. The basswood fungus thus is distinguished from C. variospora based on phylogenetic analyses and phenotype and is herein described as C. tiliae sp. nov.

Fungal Planet description sheets: 214-280.

Novel species of microfungi described in the present study include the following from South Africa: Cercosporella dolichandrae from Dolichandra unguiscati, Seiridium podocarpi from Podocarpus latifolius, Pseudocercospora parapseudarthriae from Pseudarthria hookeri, Neodevriesia coryneliae from Corynelia uberata on leaves of Afrocarpus falcatus, Ramichloridium eucleae from Euclea undulata and Stachybotrys aloeticola from Aloe sp. (South Africa), as novel member of the Stachybotriaceae fam. nov. Several species were also described from Zambia, and these include Chaetomella zambiensis on unknown Fabaceae, Schizoparme pseudogranati from Terminalia stuhlmannii, Diaporthe isoberliniae from Isoberlinia angolensis, Peyronellaea combreti from Combretum mossambiciensis, Zasmidium rothmanniae and Phaeococcomyces rothmanniae from Rothmannia engleriana, Diaporthe vangueriae from Vangueria infausta and Diaporthe parapterocarpi from Pterocarpus brenanii. Novel species from the Netherlands include: Stagonospora trichophoricola, Keissleriella trichophoricola and Dinemasporium trichophoricola from Trichophorum cespitosum, Phaeosphaeria poae, Keissleriella poagena, Phaeosphaeria poagena, Parastagonospora poagena and Pyrenochaetopsis poae from Poa sp., Septoriella oudemansii from Phragmites australis and Dendryphion europaeum from Hedera helix (Germany) and Heracleum sphondylium (the Netherlands). Novel species from Australia include: Anungitea eucalyptorum from Eucalyptus leaf litter, Beltraniopsis neolitseae and Acrodontium neolitseae from Neolitsea australiensis, Beltraniella endiandrae from Endiandra introrsa, Phaeophleospora parsoniae from Parsonia straminea, Penicillifer martinii from Cynodon dactylon, Ochroconis macrozamiae from Macrozamia leaf litter, Triposporium cycadicola, Circinotrichum cycadis, Cladosporium cycadicola and Acrocalymma cycadis from Cycas spp. Furthermore, Vermiculariopsiella dichapetali is described from Dichapetalum rhodesicum (Botswana), Ophiognomonia acadiensis from Picea rubens (Canada), Setophoma vernoniae from Vernonia polyanthes and Penicillium restingae from soil (Brazil), Pseudolachnella guaviyunis from Myrcianthes pungens (Uruguay) and Pseudocercospora neriicola from Nerium oleander (Italy). Novelties from Spain include: Dendryphiella eucalyptorum from Eucalyptus globulus, Conioscypha minutispora from dead wood, Diplogelasinospora moalensis and Pseudoneurospora canariensis from soil and Inocybe lanatopurpurea from reforested woodland of Pinus spp. Novelties from France include: Kellermania triseptata from Agave angustifolia, Zetiasplozna acaciae from Acacia melanoxylon, Pyrenochaeta pinicola from Pinus sp. and Pseudonectria rusci from Ruscus aculeatus. New species from China include: Dematiocladium celtidicola from Celtis bungeana, Beltrania pseudorhombica, Chaetopsina beijingensis and Toxicocladosporium pini from Pinus spp. and Setophaeosphaeria badalingensis from Hemerocallis fulva. Novel genera of Ascomycetes include Alfaria from Cyperus esculentus (Spain), Rinaldiella from a contaminated human lesion (Georgia), Hyalocladosporiella from Tectona grandis (Brazil), Pseudoacremonium from Saccharum spontaneum and Melnikomyces from leaf litter (Vietnam), Annellosympodiella from Juniperus procera (Ethiopia), Neoceratosperma from Eucalyptus leaves (Thailand), Ramopenidiella from Cycas calcicola (Australia), Cephalotrichiella from air in the Netherlands, Neocamarosporium from Mesembryanthemum sp. and Acervuloseptoria from Ziziphus mucronata (South Africa) and Setophaeosphaeria from Hemerocallis fulva (China). Several novel combinations are also introduced, namely for Phaeosphaeria setosa as Setophaeosphaeria setosa, Phoma heteroderae as Peyronellaea heteroderae and Phyllosticta maydis as Peyronellaea maydis. Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

Sizing up Septoria.

Septoria represents a genus of plant pathogenic fungi with a wide geographic distribution, commonly associated with leaf spots and stem cankers of a broad range of plant hosts. A major aim of this study was to resolve the phylogenetic generic limits of Septoria, Stagonospora, and other related genera such as Sphaerulina, Phaeosphaeria and Phaeoseptoria using sequences of the the partial 28S nuclear ribosomal RNA and RPB2 genes of a large set of isolates. Based on these results Septoria is shown to be a distinct genus in the Mycosphaerellaceae, which has mycosphaerella-like sexual morphs. Several septoria-like species are now accommodated in Sphaerulina, a genus previously linked to this complex. Phaeosphaeria (based on P. oryzae) is shown to be congeneric with Phaeoseptoria (based on P. papayae), which is reduced to synonymy under the former. Depazea nodorum (causal agent of nodorum blotch of cereals) and Septoria avenae (causal agent of avenae blotch of barley and rye) are placed in a new genus, Parastagonospora, which is shown to be distinct from Stagonospora (based on S. paludosa) and Phaeosphaeria. Partial nucleotide sequence data for five gene loci, ITS, LSU, EF-1α, RPB2 and Btub were generated for all of these isolates. A total of 47 clades or genera were resolved, leading to the introduction of 14 new genera, 36 new species, and 19 new combinations. TAXONOMIC NOVELTIES: New genera - Acicuseptoria Quaedvlieg, Verkley & Crous, Cylindroseptoria Quaedvlieg, Verkley & Crous, Kirstenboschia Quaedvlieg, Verkley & Crous, Neoseptoria Quaedvlieg, Verkley & Crous, Neostagonospora Quaedvlieg, Verkley & Crous, Parastagonospora Quaedvlieg, Verkley & Crous, Polyphialoseptoria Quaedvlieg, R.W. Barreto, Verkley & Crous, Ruptoseptoria Quaedvlieg, Verkley & Crous, Septorioides Quaedvlieg, Verkley & Crous, Setoseptoria Quaedvlieg, Verkley & Crous, Stromatoseptoria Quaedvlieg, Verkley & Crous, Vrystaatia Quaedvlieg, W.J. Swart, Verkley & Crous, Xenobotryosphaeria Quaedvlieg, Verkley & Crous, Xenoseptoria Quaedvlieg, H.D. Shin, Verkley & Crous. New species - Acicuseptoria rumicis Quaedvlieg, Verkley & Crous, Caryophylloseptoria pseudolychnidis Quaedvlieg, H.D. Shin, Verkley & Crous, Coniothyrium sidae Quaedvlieg, Verkley, R.W. Barreto & Crous, Corynespora leucadendri Quaedvlieg, Verkley & Crous, Cylindroseptoria ceratoniae Quaedvlieg, Verkley & Crous, Cylindroseptoria pistaciae Quaedvlieg, Verkley & Crous, Kirstenboschia diospyri Quaedvlieg, Verkley & Crous, Neoseptoria caricis Quaedvlieg, Verkley & Crous, Neostagonospora caricis Quaedvlieg, Verkley & Crous, Neostagonospora elegiae Quaedvlieg, Verkley & Crous, Paraphoma dioscoreae Quaedvlieg, H.D. Shin, Verkley & Crous, Parastagonospora caricis Quaedvlieg, Verkley & Crous, Parastagonospora poae Quaedvlieg, Verkley & Crous, Phlyctema vincetoxici Quaedvlieg, Verkley & Crous, Polyphialoseptoria tabebuiae-serratifoliae Quaedvlieg, Alfenas & Crous, Polyphialoseptoria terminaliae Quaedvlieg, R.W. Barreto, Verkley & Crous, Pseudoseptoria collariana Quaedvlieg, Verkley & Crous, Pseudoseptoria obscura Quaedvlieg, Verkley & Crous, Sclerostagonospora phragmiticola Quaedvlieg, Verkley & Crous, Septoria cretae Quaedvlieg, Verkley & Crous, Septoria glycinicola Quaedvlieg, H.D. Shin, Verkley & Crous, Septoria oenanthicola Quaedvlieg, H.D. Shin, Verkley & Crous, Septoria pseudonapelli Quaedvlieg, H.D. Shin, Verkley & Crous, Setophoma chromolaenae Quaedvlieg, Verkley, R.W. Barreto & Crous, Setoseptoria phragmitis Quaedvlieg, Verkley & Crous, Sphaerulina amelanchier Quaedvlieg, Verkley & Crous, Sphaerulina pseudovirgaureae Quaedvlieg, Verkley & Crous, Sphaerulina viciae Quaedvlieg, H.D. Shin, Verkley & Crous, Stagonospora duoseptata Quaedvlieg, Verkley & Crous, Stagonospora perfecta Quaedvlieg, Verkley & Crous, Stagonospora pseudocaricis Quaedvlieg, Verkley, Gardiennet & Crous, Stagonospora pseudovitensis Quaedvlieg, Verkley & Crous, Stagonospora uniseptata Quaedvlieg, Verkley & Crous, Vrystaatia aloeicola Quaedvlieg, Verkley, W.J. Swart & Crous, Xenobotryosphaeria calamagrostidis Quaedvlieg, Verkley & Crous, Xenoseptoria neosaccardoi Quaedvlieg, H.D. Shin, Verkley & Crous. New combinations - Parastagonospora avenae (A.B. Frank) Quaedvlieg, Verkley & Crous, Parastagonospora nodorum (Berk.) Quaedvlieg, Verkley & Crous, Phaeosphaeria papayae (Speg.) Quaedvlieg, Verkley & Crous, Pseudocercospora domingensis (Petr. & Cif.) Quaedvlieg, Verkley & Crous, Ruptoseptoria unedonis (Roberge ex Desm.) Quaedvlieg, Verkley & Crous, Septorioides pini-thunbergii (S. Kaneko) Quaedvlieg, Verkley & Crous, Sphaerulina abeliceae (Hiray.) Quaedvlieg, Verkley & Crous, Sphaerulina azaleae (Voglino) Quaedvlieg, Verkley & Crous, Sphaerulina berberidis (Niessl) Quaedvlieg, Verkley & Crous, Sphaerulina betulae (Pass.) Quaedvlieg, Verkley & Crous, Sphaerulina cercidis (Fr.) Quaedvlieg, Verkley & Crous, Sphaerulina menispermi (Thüm.) Quaedvlieg, Verkley & Crous, Sphaerulina musiva (Peck) Quaedvlieg, Verkley & Crous, Sphaerulina oxyacanthae (Kunze & J.C. Schmidt) Quaedvlieg, Verkley & Crous, Sphaerulina patriniae (Miura) Quaedvlieg, Verkley & Crous, Sphaerulina populicola (Peck) Quaedvlieg, Verkley & Crous, Sphaerulina quercicola (Desm.) Quaedvlieg, Verkley & Crous, Sphaerulina rhabdoclinis (Butin) Quaedvlieg, Verkley & Crous, Stromatoseptoria castaneicola (Desm.) Quaedvlieg, Verkley & Crous. Typifications: Epitypifications - Phaeosphaeria oryzae I. Miyake, Phaeoseptoria papayae Speg.; Neotypification - Hendersonia paludosa Sacc. & Speg.

First Report of Enterobacter cowanii Causing Bacterial Spot on Mabea fistulifera, a Native Forest Species in Brazil.

In the summer of 2011, in a nursery located in Viçosa City, Minas Gerais State, brownish, necrotic, irregular spots were observed on leaves of Mabea fistulifera Mart. (Euphorbiaceae), an indigenous forest species commonly found in Brazil. Around 6,300 seedlings were evaluated and as many as 60% of them showed disease symptoms, including severe defoliation and plant death. Leaves with coalescing lesions turned papery in texture and had a blighted appearance. Bacterial colonies were isolated from these symptomatic leaves on King B's medium and identified based on biochemical and molecular analysis, as a member of the Enterobacteriaceae family. Like other members of the Enterobacteriaceae family, the bacteria were facultative anaerobic, gram-negative, cream-colored on YDC medium, urease and oxidase negative, as well as catalase and asparagine positive. Bacterial DNA was extracted from pure culture grown overnight in liquid 523 medium at 28°C using the Wizard Genomic DNA Purification kit (Promega) and conserved sequences in 16S rDNA (3) and rpoB (1) were amplified by PCR. The sequence of the 1,300-bp 16S rDNA fragment and the 750-bp rpoB gene were analyzed by NCBI BLAST. Related sequences were aligned and analyzed by ClustalW in MEGA 5 software. Phylogenetic analysis by maximum likelihood, using PAUP version 4.0 and TBR algorithm with 1,000 bootstrap replications, grouped the isolate in a clade with Enterobacter cowanii and the result showed 99% and 98% identity to the 16s rDNA and rpoB, respectively. The isolate clustered closely with the type strain of E. cowanii in both phylogenetic trees constructed. Pathogenicity tests were carried out by inoculating leaves of healthy seedlings either by spraying or cutting with a scissor previously dipped into a 108 CFU/ml bacterial suspension. The experiment was in a completely randomized design, with six replications. A pot with one plant was considered one experimental unit. Control seedlings were sprayed or cut with a scissor treated with saline solution. Prior to and after inoculation, plants were kept in a humid chamber for 24 h at 26°C in the dark and at room temperature. Subsequently, plants were transferred to growth chamber at 26°C, under a 12-h photoperiod (40 µmol/s/m2). Consistent with the symptoms observed originally, 7 days after inoculation, all seedlings developed leaf spots. No characteristic symptoms could be observed in the negative control. Furthermore, Koch's postulates were confirmed by reisolation of the bacterium from symptomatic tissues. In summary, the phenotypic, biochemical, and molecular tests identified the pathogen as E. cowanii. Recently, E. cowanii was isolated from Eucalyptus trees with symptoms of bacterial blight, although its pathogenicity was not demonstrated (2). To the best of our knowledge, this is the first report of a member of the Enterobacteriaceae family causing disease in M. fistulifera. The result has a great importance to better understand the role of E. cowanii as a pathogen-causing disease on a forest species. References: (1) C. L. Brady et al. Syst. Appl. Microbiol. 31:447, 2008. (2) C. L. Brady et al. Lett. Appl. Microbiol. 49:461, 2009. (3) W. G. Weisburg et al. J. Bacteriol. 173:697, 1991.

Isoenzyme analysis of Arthrobotrys, a nematode-trapping fungus.

Extraction and isoenzyme analysis of four isolates of Arthrobotrys including A. musiformis, A. robusta and A. conoides were conducted. Among the 14 enzymes studied by starch gel electrophoresis, using morpholine-citrate as gel/electrode buffer, the following nine enzymes showed interpretable banding patterns: alpha-esterase, fumarase, hexokinase, isocitrate dehydrogenase, leucine aminopeptidase, malate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase and phosphoglucoisomerase. All isolates studied displayed typical isoenzyme phenotypes for each species. Two isolates of A. conoides differed in their alpha-isoesterase banding patterns, but no differences were observed for the other enzymes. The assay was satisfactory for enzyme extraction and resolution of Arthrobotrys and could be used in future taxonomic and genetic studies of this organism.

Resistance of Eucalyptus Clones to Ceratocystis fimbriata.

Ceratocystis fimbriata, the inciting agent of wilt, canker, and dieback in eucalyptus plantations, was first reported in Brazil in 1998. There is no information regarding the resistance of Eucalyptus spp. to this pathogen. We determined the reaction of 18 Brazilian, commercial clones of the hybrid Eucalyptus grandis × E. urophylla to inoculation by two isolates of the pathogen in two experiments. Container-grown, 8-month-old rooted cuttings of each clone were wound-inoculated with a conidial suspension (2.5 × 106/ml). Plants similarly injected with sterile distilled water served as controls. The plants were evaluated after 30 days for length of xylem discoloration. There was a significant isolate by clone interaction, but most clones reacted similarly to the two isolates. Six clones, including one observed to be highly susceptible under field conditions, were highly susceptible (>20 cm discoloration) to one or both isolates of the pathogen. Four clones showed no more discoloration with either isolate than with the control inoculations, and the other eight clones were intermediate in susceptibility. Thus, highly resistant clones are available to manage this disease.

Eucalyptus Rust: A Disease with the Potential for Serious International Implications.

Eucalyptus spp. are propagated extensively as non-natives in plantations in many parts of the tropics and sub-tropics. A number of diseases result in serious losses to this economically important forest resource. Eucalyptus rust, caused by Puccinia psidii, is one such example. The economic losses due to this disease are the result of infections of seedlings, young trees, and coppice. P. psidii occurs predominately in Central and South America, but reports of a similar rust are known from other areas. Eucalyptus rust is a remarkable disease in that the pathogen is not known on eucalypts in their centers of origin. It has apparently originated on native Myrtaceae in South America and is highly infective on some Eucalyptus spp. planted there. P. psidii causes one of the most serious forestry diseases in Brazil and is considered to be the most serious threat to eucalypt plantations worldwide. Advances in eucalyptus rust research are reviewed here, with a focus on topics such as distribution, host range, pathogen specialization, symptomatology, etiology, epidemiology, and control.

Genera of diaporthalean coelomycetes associated with leaf spots of tree hosts.

Four different genera of diaporthalean coelomycetous fungi associated with leaf spots of tree hosts are morphologically treated and phylogenetically compared based on the DNA sequence data of the large subunit nuclear ribosomal DNA gene (LSU) and the internal transcribed spacers and 5.8S rRNA gene of the nrDNA operon. These include two new Australian genera, namely Auratiopycnidiella, proposed for a leaf spotting fungus occurring on Tristaniopsis laurina in New South Wales, and Disculoides, proposed for two species occurring on leaf spots of Eucalyptus leaves in Victoria. Two new species are described in Aurantiosacculus, a hitherto monotypic genus associated with leaf spots of Eucalyptus in Australia, namely A. acutatus on E. viminalis, and A. eucalyptorum on E. globulus, both occurring in Tasmania. Lastly, an epitype specimen is designated for Erythrogloeum hymenaeae, the type species of the genus Erythrogloeum, and causal agent of a prominent leaf spot disease on Hymenaea courbaril in South America. All four genera are shown to be allied to Diaporthales, although only Aurantiosacculus (Cryphonectriaceae) could be resolved to family level, the rest being incertae sedis.

Fungal Planet description sheets: 69-91.

Novel species of microfungi described in the present study include the following from Australia: Bagadiella victoriae and Bagadiella koalae on Eucalyptus spp., Catenulostroma eucalyptorum on Eucalyptus laevopinea, Cercospora eremochloae on Eremochloa bimaculata, Devriesia queenslandica on Scaevola taccada, Diaporthe musigena on Musa sp., Diaporthe acaciigena on Acacia retinodes, Leptoxyphium kurandae on Eucalyptus sp., Neofusicoccum grevilleae on Grevillea aurea, Phytophthora fluvialis from water in native bushland, Pseudocercospora cyathicola on Cyathea australis, and Teratosphaeria mareebensis on Eucalyptus sp. Other species include Passalora leptophlebiae on Eucalyptus leptophlebia (Brazil), Exophiala tremulae on Populus tremuloides and Dictyosporium stellatum from submerged wood (Canada), Mycosphaerella valgourgensis on Yucca sp. (France), Sclerostagonospora cycadis on Cycas revoluta (Japan), Rachicladosporium pini on Pinus monophylla (Netherlands), Mycosphaerella wachendorfiae on Wachendorfia thyrsifolia and Diaporthe rhusicola on Rhus pendulina (South Africa). Novel genera of hyphomycetes include Noosia banksiae on Banksia aemula (Australia), Utrechtiana cibiessia on Phragmites australis (Netherlands), and Funbolia dimorpha on blackened stem bark of an unidentified tree (USA). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

Phylogeny and taxonomy of obscure genera of microfungi.

The recently generated molecular phylogeny for the kingdom Fungi, on which a new classification scheme is based, still suffers from an under representation of numerous apparently asexual genera of microfungi. In an attempt to populate the Fungal Tree of Life, fresh samples of 10 obscure genera of hyphomycetes were collected. These fungi were subsequently established in culture, and subjected to DNA sequence analysis of the ITS and LSU nrRNA genes to resolve species and generic questions related to these obscure genera. Brycekendrickomyces (Herpotrichiellaceae) is introduced as a new genus similar to, but distinct from Haplographium and Lauriomyces. Chalastospora is shown to be a genus in the Pleosporales, with two new species, C. ellipsoidea and C. obclavata, to which Alternaria malorum is added as an additional taxon under its oldest epithet, C. gossypii. Cyphellophora eugeniae is newly described in Cyphellophora (Herpotrichiellaceae), and distinguished from other taxa in the genus. Dictyosporium is placed in the Pleosporales, with one new species, D. streliziae. The genus Edenia, which was recently introduced for a sterile endophytic fungus isolated in Mexico, is shown to be a hyphomycete (Pleosporales) forming a pyronellea-like synanamorph in culture. Thedgonia is shown not to represent an anamorph of Mycosphaerella, but to belong to the Helotiales. Trochophora, however, clustered basal to the Pseudocercospora complex in the Mycosphaerellaceae, as did Verrucisporota. Vonarxia, a rather forgotten genus of hyphomycetes, is shown to belong to the Herpotrichiellaceae and Xenostigmina is confirmed as synanamorph of Mycopappus, and is shown to be allied to Seifertia in the Pleosporales. Dichotomous keys are provided for species in the various genera treated. Furthermore, several families are shown to be polyphyletic within some orders, especially in the Capnodiales, Chaetothyriales and Pleosporales.

Resistance to rust ( Puccinia psidii Winter) in eucalyptus: mode of inheritance and mapping of a major gene with RAPD markers.

Rust is one of the most-damaging eucalypt diseases in Brazil and is considered a potential threat to eucalypt plantations worldwide. To determine the mode of inheritance of resistance in the Eucalyptus grandis- Puccinia psidii pathosystem, ten full-sib families, generated from crosses between susceptible and resistant trees, were inoculated with a single-pustule isolate of the pathogen and rust severity was scored. The observed segregation ratios in segregating families suggested major gene control of rust resistance, although clearly incomplete penetrance, variable expressivity and minor genes are also involved in the global rust-resistance response. To identify markers linked to the resistance locus, screening of RAPD polymorphisms was conducted using bulked segregant analysis in a large full-sib family. A linkage group was built around the Ppr1 gene ( P. psidii resistance gene 1) encompassing six RAPD markers, with a genetic window spanning 5 cM with the two most-closely linked flanking markers. Besides these two flanking markers, RAPD marker AT9/917 co-segregated with Ppr1 without a single recombinant in 994 meioses. This tightly linked marker should prove useful for marker-assisted introgression and will provide an initial lead for a positional cloning effort of this resistance allele. This is the first report of a disease resistance gene identified in Eucalyptus, and one of the few examples of the involvement of a major gene in a non-coevolved pathosystem.

Isoenzyme analysis of Arthrobotrys, a nematode-trapping fungus

Extraction and isoenzyme analysis of four isolates of Arthrobotrys including A. musiformis, A. robusta and A. conoides were conducted. Among the 14 enzymes studied by starch gel electrophoresis, using morpholine-citrate as gel/electrode buffer, the following nine enzymes showed interpretable banding patterns: alpha-esterase, fumarase, hexokinase, isocitrate dehydrogenase, leucine aminopeptidase, malate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase and phosphoglucoisomerase. All isolates studied displayed typical isoenzyme phenotypes for each species. Two isolates of A. conoides differed in their alpha-isoesterase banding patterns, but no differences were observed for the other enzymes. The assay was satisfactory for enzyme extraction and resolution of Arthrobotrys and could be used in future taxonomic and genetic studies of this organism.

A priori choice of hybrid parents in plants

Plant breeding deals with high-yielding genotypes. However, how best to choose parents of these genotypes remains an unsolved question. Here, we focus on a priori choice based on parental distances by means of agronomic and molecular data. Despite numerous theoretical and empirical studies, a priori choice continues to be a controversial procedure. Both success and failure are commonly reported. We looked at these ambiguous results in order to investigate their possible causes. A total of 139 articles on genetic divergence were sampled to examine aspects such as type and number of markers utilized. We suggest that the mean number of 160, 281 and 25 for RAPD and RFLP markers, and SSR loci, respectively, which we found in these papers, should be increased for accurate analysis. A second sample composed of 54 articles was used to evaluate the divergence-heterosis association. Most of them (28) detected positive divergence-heterosis association, whereas 26 revealed negative or inconclusive results. We examined several causes that influence a priori choice positively and negatively.