Morphological,cultural and pathogenic characteristics of Coniothyrium zuluense isolates from different plantation regions in South Africa

Coniothyrium canker caused by Coniothyrium zuluense, is a serious stem canker disease of Eucalyptus species in sub-tropical regions of South Africa. This disease is typified by necrotic bark lesions that coalesce to form large kino-impregnated cankers along the stems of trees. The strategy currently used to manage Coniothyrium canker in plantations is to deploy Eucalyptus species or clones that are resistant to the disease. Considerable success has already been achieved in this regard, but the long-term durability of resistance is of concern. Thus, forest managers are interested in the genetic diversity of the pathogen and its potential to overcome disease resistance in planting stock. In this study, 344 isolates of C. zuluense from different plantation regions in South Africa were compared on the basis of colony colour, conidial morphology, growth characteristics on agar and pathogenicity to a susceptible E. grandis clone. Conidia of all C. zuluense isolates measured were similar in size and shape. The fungus is slow growing in culture, which is indicative of its apparent biotrophic habit, with optimum growth observed at 30 °C. Isolates of C. zuluense displayed considerable variation in colony colour and pathogenicity in inoculation trials. Variation in morphology and pathogenicity amongst isolates suggests that C. zuluense has been present in South Africa for an extended period of time, or that it is changing rapidly due to strong directional selection pressures. This revised version was published online in June 2006 with corrections to the Cover Date.     

Bambusicolous fungi in Japan (7): a new coelomycetous genus, <Emphasis Type="Italic">Versicolorisporium</Emphasis>

A new genus, Versicolorisporium, is established for the coelomycetous fungus collected in Japan on dead culms of the bamboos Pleioblastus chino and Sasamorpha borealis. The type species of the genus, V. triseptatum, is characterized by the production of holoblastic, 3-septate, obovoid, versicolored conidia. Versicolorisporium is similar to Toxosporiella, Neohendersonia, Toxosporiopsis, and Scolicosporium in having versicolored conidia, but differs from these genera by the uniloculate pycnidial conidiomata with a periphysate ostiole, lacking paraphyses, and the conidia without black-banded septa. A BLAST search using LSU nrDNA sequence indicates that the new genus is a member of Pleosporales, Dothideomycetes.     

Species of Mycosphaerellaceae and Teratosphaeriaceae on native Myrtaceae in Uruguay: evidence of fungal host jumps

Mycosphaerella species are well-known causal agents of leaf diseases on many economically and ecologically important plant species. In Uruguay, a relatively large number of Mycosphaerellaceae and Teratosphaeriaceae are found on Eucalyptus, but nothing is known of these fungi on native Myrtaceae. The aim of this study was to identify Mycosphaerellaceae and Teratosphaeriaceae species associated with leaf diseases on native Myrtaceae in Uruguay and to consider whether host jumps by the pathogen from introduced Eucalyptus to native Myrtaceae have occurred. Several native forests throughout the country were surveyed with special attention given to those located close to Eucalyptus plantations. Five species belonging to the Mycosphaerellaceae and Teratosphaeriaceae clades were found on native Myrtaceous trees and three of these had previously been reported on Eucalyptus in Uruguay. Those occurring both on Eucalyptus and native Myrtaceae included Pallidocercospora heimii, Pseudocercospora norchiensis, and Teratosphaeria aurantia. In addition, Mycosphaerella yunnanensis, a species known to occur on Eucalyptus but not previously recorded in Uruguay, was found on leaves of two native Myrtaceous hosts. Because most of these species occur on Eucalyptus in countries other than Uruguay, it appears that they were introduced in this country and have adapted to be able to infect native Myrtaceae. These apparent host jumps have the potential to result in serious disease problems and they should be carefully monitored.     

The Caloscyphaceae (Pezizomycetes, Ascomycota), with a new genus

The family Caloscyphaceae with a single genus, Caloscypha, has been considered to include a single species, C. fulgens. Study of an overlooked second species, Caloscypha incarnata from North Africa and Italy, using SSU, LSU rDNA, and morphology allows placement of this species in a new genus, Kallistoskypha, in the Caloscyphaceae. This fungus is found in association with Eucalyptus species. The species was recently redescribed from Spain under the name Marcelleina parvispora. Caloscypha fulgens, the type species of the genus Caloscypha, shows sequence variation from across its range.     

Five additional genera of conidial lichen-forming fungi from Europe

Three remarkable new genera of conidial lichen-forming fungi, with pycnidial or acervular conidiomata are described and illustrated.Hastifera tenuispora gen. et spec. nov. from the South-Tyrol, Italy, is characterized by very long and narrow hyaline conidia produced in pycnidial conidiomata immersed in thalline warts.Lichingoldia gyalectiformis gen. et spec. nov. from rocks subject to inundation by freshwater in Norway has long sigmoidly curved conidia which appear to be adapted to dispersal in water.Woessia fusarioides gen. et spec. nov. from aQuercus stump in the Burgenland, Austria, has a finely granular thallus and disc-like conidiomata producing falcate conidia; this species is also of interest in that it hasChlorella as the photobiont. The recently described hyphomyceteCheiromycina flabelliformis B. Sutton is reported from Austria for the first time, and is also lichenized. Recent collections ofNigropuncta rugulosa D. Hawksw. from Austria and Italy also show that this species is lichenized rather than parasymbiotic. In all five cases the fungal hyphae of the conidiogenous structures are continuous with those in intimate contact with cells of the algal partners and the biological relationship appears to be mutualistic giving rise to stable crustose lichen thalli.     

A new species of Pseudorobillarda, an endophyte from Thuja occidentalis in Canada, and a key to the species

Pseudorobillarda monica sp. nov. is described and illustrated. The endophyte was isolated from living leaves and bark of twigs of a Thuja occidentalis bonsai (>90 years old) at the Montréal Botanical Garden and ornamental trees in Montréal urban plantations. This pycnidial fungus is typical of the genus in morphology but clearly differs from other species in Pseudorobillarda by the distinct size of the conidiomata and the shape and size of conidia and paraphyses. Its taxonomic placement is discussed and a key to the species of Pseudorobillarda is provided.     

A serious canker disease of Eucalyptus in South Africa caused by a new species of Coniothyrium

Eucalyptus spp. are being propagated extensively as exotics in plantations in South Africa, and many other parts of the world. In South Africa, a number of diseases result in serious losses to this resource. This paper describes a new and very damaging stem canker disease, which has recently appeared on plantation-grown eucalyptus in South Africa. The disease, first noted in an isolated location in Zululand is now common in other parts of the country, and is typified by discrete necrotic lesions on stems. These lesions coalesce to form large, gum-impregnated cankers and malformed stems. The causal agent of the disease, as inferred from pathogenicity tests, is a new species of Coniothyrium described here as C. zuluense. This fungus is a serious impediment to eucalypt propagation in South Africa, and is most likely a threat to similar forest industries elsewhere in the world.     

Pycnidial development ofPhyllosticta harai andSphaeropsis sp.

The development of conidiomatal structures is divided into three stages: primordia, cavity formation, and conidiogenesis. These ontogenetic features of conidiomata indicate diversity. This study clearly shows the difference in pycnidial development betweenPhyllosticta harai and a species ofSphaeropsis. InP. harai, a cavity is formed at the center of the pycnidium following the meristogenous or symphogenous primordium formation. This process is characterized by autolysis of cells at the pycnidium center. The pycnidial primordium ofSphaeropsis sp. is meristogenous. It can be assumed that the cavity is formed by dispersion and spacing of original hypha, with subsequent hypha filling the spaces between hyphal cells. The cavity enlarges gradually due to the mechanical force caused by successive conidium production and increasing conidial size.     

Pyrenochaeta keratinophila sp. nov., isolated from an ocular infection in Spain

The new coelomycete Pyrenochaeta keratinophila, isolated from corneal scrapings of a case of keratitis in Spain, is described and illustrated. This fungus is morphologically characterized by grey-olivaceous to greenish olivaceous colonies, scarce pycnidial setae placed mainly near the ostiole and production of phialoconidia from the aerial mycelium. The latter feature is unknown in any other species of the genus Pyrenochaeta. Sequencing of the ITS rDNA region of this clinical strain confirmed this proposal and revealed its close genetic relationship with the Leptosphaeriaceae.     

<Emphasis Type="Italic">Phialemoniopsis endophytica</Emphasis> sp. nov., a new species of endophytic fungi from <Emphasis Type="Italic">Luffa cylindrica</Emphasis> in Henan,China

During a survey of endophytic fungi in the cucurbit plants collected from Henan, China, a new species, Phialemoniopsis endophytica was isolated from the lower stem of Luffa cylindrica. It differs from other Phialemoniopsis species by its cylindrical to flask-shaped phialides, falcate conidia with blunt ends, ostiolate pycnidium-like conidiomata without marginal setae and ellipsoidal chlamydospores. Multi-locus (ITS, LSU, ACT, and TUB) phylogenetic analysis confirmed that P. endophytica is distinct from other species. A synopsis of the morphological characters of the new species is provided.     

Cretaceous and Paleogene Bourgueticrinina (Echinodermata,Crinoidea) of the USSR

The theca and the columnals of twenty-two lateCretaceous species of the genus Bourgueticrinus (including two new species), of one species of the genus Democrinus, of four species of the genus Conocrinus (including one new species) and of one species of the genus Paleobathycrinus known from USSR are figured and shortly described. Biometric reconstructions of stems for B. aequalis, B. bellus, B. danicus, B. fischeri and C. tauricus nov. sp. are given. A new index is used to suggest the relative flexibility of stem. Decrease in dimension and flexibility of the arms in several species take place simultaneously with an increase of stem flexibility. This fact seems to be closely related to environmental changes.     

Calonectria leaf blight of Eucalyptus: A global review

Calonectria (= Cylindrocladium), an internationally recognised fungal ascomycete genus, causes significant diseases on numerous crops of forestry, horticultural and agricultural interest. Eucalyptus, an economically important multipurpose plantation forestry species, is severely threatened by Calonectria leaf blight (CLB) disease in Brazil, Australia, China, Indonesia, Vietnam and India. The disease causes serious mortality in the nurseries/plantations and yield losses due to defoliation. Since the first report of Calonectria in 1867, efforts have been made for the identification and characterisation of this vastly diverse hypocrealean genus. Currently, the genus Calonectria harbours 131 species grouped within 11 species complexes, and broadly categorised into the Prolate and Sphaero-Naviculate groups. Globally, 35 Calonectria species distributed in seven species complexes cause CLB of Eucalyptus, out of which 29 belong to the Prolate group and five to the Sphaero-Naviculate group. Likewise, 28 Calonectria species distributed in eight species complexes have been reported in association with infected Eucalyptus tissues and plantation soil, however, their pathogenicity remains to be determined. Given the importance of CLB of Eucalyptus, this review compiles its global impact, shifts in taxonomy and nomenclature of Calonectria, pathogenesis mechanism, defence response of Eucalyptus upon infection and disease management. This study identifies and provides direction to crucial areas of future research on CLB which is severely impacting Eucalyptus plantations globally.     

ECOLOGY OF FOLIICOLOUS LICHENS AT THE ‘ BOTARRAMA ’ TRAIL (COSTA RICA), A NEOTROPICAL RAINFOREST. IV. SPECIES ASSOCIATIONS,THEIR SALIENT FEATURES AND THEIR DEPENDENCE ON ENVIRONMENTAL VARIABLES

A community ecology approach using an association of species test and a principal component analysis resulted in the recognition of two major and two minor foliicolous lichen communities in a neotropical rainforest. The major communities are governed by microclimatic factors, one characteristic of the shady understorey and the other confined to light gaps. The minor communities are due to subtle phorophyte preferences towards palm and dicot leaves. The shady understorey community is dominated by the families Arthoniaceae , Opegraphaceae , Trichotheliaceae and Pilocarpaceae , which predominantly have Phycopeltis as their phycobiont, thin thalli, abundant sexual reproduction, small ascospores produced in high numbers, and pycnidial conidiomata. The light-gap community is mainly composed of the families Gomphillaceae and Ectolechiaceae , with Trebouxia as their phycobiont, thickly crystalline or whitish, dispersed thalli, frequent asexual reproduction, large ascospores produced in low numbers, and specialized campylidia and hyphophores as conidiomata. Phycobiont, thallus structure, and the mode of reproduction are considered as adaptations to different microsites, whereas the shape and size of ascospores and conidia seem to be of less importance. The foliicolous lichen communities reflect the spatial and temporal structure of the forest, in particular the continuity of the shady understorey in comparison to the discontinuity of the light gaps. While the formation of the shady understorey community follows more deterministic patterns, the light-gap community exhibits high stochasticity.     

Medium- and Light-dependence of Growth and Conidiomata Production in Phaeocytosporella zeae Pathogenic to Maize

Culture appearance, mycelium growth and pycnidial conidiomata formation in Phaeocytosporella zeae cultivated on potato dextrose agar (PDA), Leonian agar and carnation leaf agar (CLA) during permanent dark (25 C) or a 12-h photoperiod (24/18°C) are described. Different media and light conditions significantly affected fungus growth and the occurrence of conidiomata.
Dark conditions favoured more mycelium growth of the fungus than alternating light and dark. Moreover, fungus growth was more rapid on PDA and CLA media than on Leonian agar. Carnation leaf agar and a 12-h photoperiod provided excellent conditions for the promotion of rapid conidiomata formation in a number of P. zeae isolates.     

Isolation of microsatellite loci from spotted gum (Corymbia variegata), and cross‐species amplification in Corymbia and Eucalyptus

Corymbia variegata (spotted gum) is an important commercial hardwood timber species in Australia. Fourteen polymorphic microsatellite loci were isolated from C. variegata, with 3–5 alleles amplified in three individuals examined. Cross‐species amplification in Corymbia was successful for all primer pairs, while 10 loci (71%) were successfully transferred to at least one species in the closely related genus Eucalyptus.     

Nouvelles espèces d’Ancyrocrinus et d’Ammonicrinus,crinoïdes à pédoncule spécialisé du Dévonien armoricain (Brest,France)

New species of Ancyrocrinus and Ammonicrinus, crinoids, crinoids with specialized stem from the Armorican Devonian (Brest, France). The discovery of the oldest tetrameral grapnels of Ancyrocrinus, A. crozonensis n. sp., in the Lower Eifelian modifies considerably the previous evolutionary scheme and sets the problem of the transition from tetrameral to pentameral symmetry in the ancyrocrinid holdfasts. The presence of a new species of Ammonicrinus, A. kerdreoletensis n. sp., in the Upper Emsian suggests a North-Gondwanan origin of the genus. Its highly specialized structure of the stem, characteristic of the genus, was developed earlier than previously recognized. To cite this article: J. Le Menn, P.A. Jaouen, C. R. Palevol 2 (2003).