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Ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) are small wood-boring insects that live in an obligate symbiosis with fungi, which serve as their primary food source. Beetles residing in the genus Euwallacea have evolved a unique association with a clade of Fusarium that falls within the aptly named Ambrosia Fusarium Clade (AFC). The discovery of the invasive polyphagous shot hole borer, E. fornicatus, in South Africa, has heightened awareness of ambrosia beetles and their symbionts in the country. In this study, we investigated the Fusarium symbionts of three species of Euwallacea in South Africa, with a specific focus on those associated with E. xanthopus. Isolations of Fusarium strains from both living and dissected beetles yielded nearly 100 isolates. Using multigene phylogenetic analyses, these isolates were identified as six different Fusarium species. Fusarium hypothenemi and F. euwallaceae have previously been reported from South Africa. Fusarium pseudensiforme and Fusarium AF-6 are new records for the country. The remaining two species are new to science and are described here as F. rufum sp. nov. and F. floriferum sp. nov. Targeted fungal isolation from specific beetle body parts revealed that the AFC species collected were typically associated with the dissected beetle heads and helped us identify the likely nutritional symbiont of E. xanthopus. This study highlights the understudied diversity of fungal associates of ambrosia beetles present in South Africa. [ABSTRACT FROM AUTHOR]

Several economically important pathogens, including species of Chrysoporthe, pose a threat to the rapidly expanding eucalypt plantation industry in Southeast Asia. During 2019 disease surveys in Riau and Kalimantan (Indonesia), cankers were observed on eucalypt trees and a collection of fungal isolates was obtained from them. The aim of this study was to confirm the identity of the isolates and to evaluate their relative pathogenicity on different eucalypt clones. Using the DNA sequence data based on the internal transcribed spacer (ITS) region of the ribosomal DNA and two regions of the β-tubulin gene (TUB1 and TUB2), 31 fungal isolates were identified as C. deuterocubensis. Pathogenicity trials showed that C. deuterocubensis isolates differed in their pathogenicity and that different eucalypt genotypes differed in their susceptibility to the pathogen. These results will provide valuable information to reduce the threat of stem canker to future eucalypt plantation development. [ABSTRACT FROM AUTHOR]

Graphium species form a well-supported monophyletic lineage within the Microascales (Ascomycota). Members of this genus can be found in association with bark beetles, as well as on tree wounds and in soils. During surveys of bark and ambrosia beetle–associated fungi and cavities made by woodpeckers on hardwood trees in Poland, many isolates with an affinity to Graphium were recovered. They were identified based on their morphological characters and sequence data for the internal transcribed spacer (ITS), 28S rDNA, β-tubulin (TUB2), and translation elongation factor 1-α (TEF1) gene regions. The results revealed five new species, described here as G. brachiatum, G. longistipitatum, G. polonicum, G. radicatum, and G. trypophloei. [ABSTRACT FROM AUTHOR]

Diseases increasingly threaten the rapidly expanding eucalypt plantation industry of Indonesia. Of these, leaf blight caused by Calonectria spp. is considered amongst the more important problems, causing losses both in production nurseries and plantations. Using DNA sequence data based on the translation elongation factor 1-alpha, β-tubulin, calmodulin, and histone H3 gene regions, 163 isolates of Calonectria spp. obtained from diseased eucalypt seedlings in nurseries and infected leaves in plantations were identified as Calonectria acicola, C. hawksworthii, C. lombardiana, C. multiseptata, C. pseudoreteaudii and C. reteaudii. Of these, C. lombardiana was by far the most commonly isolated and accounted for approximately 84% of the isolates. Given the predominance of this fungus, it is interesting that it has not previously been reported from Indonesia. This is also the first report of C. pseudoreteaudii and C. acicola from the country. All six species of Calonectria were found to be pathogenic to eucalypts in artificial inoculation studies. Calonectria lombardiana was generally the most pathogenic species and eucalypt genotypes displayed different levels of susceptibility, providing confidence that disease caused by this fungus can be reduced by selecting disease-tolerant planting stock. [ABSTRACT FROM AUTHOR]

Eucalypt plantations in South Africa make up an important part of the local forestry industry. Recently, one-year-old nursery plants of a Eucalyptus grandis × Eucalyptus urophylla variety displayed symptoms of leaf and shoot anthracnose disease. Samples were collected from these plants and isolations were made from the disease symptoms. Isolates were identified based on their morphological characteristics and DNA sequence data for eight gene regions. Phylogenetic analyses led to the isolates being identified as Colletotrichum theobromicola and the reduction of Colletotrichum pseudotheobromicola to synonymy with the former species. Pathogenicity trials with isolates of C. theobromicola were conducted on clones of E. grandis and hybrids of E. grandis × E. urophylla and E. grandis × Eucalyptus camaldulensis. Resulting symptoms were similar to those found on naturally infected plants and the fungus was re-isolated from the infections. Colletotrichum theobromicola is known to cause anthracnose on various plants including eucalypts in Brazil, but this is the first record of the pathogen in South Africa. [ABSTRACT FROM AUTHOR]

The Ophiostomatales (Ascomycota) accommodates more than 300 species characterized by similar morphological adaptations to arthropod dispersal. Most species in this order are wood-inhabiting fungi associated with bark or ambrosia beetles. However, a smaller group of species occur in other niches such as in soil and Protea infructescences. Recent surveys of Termitomyces fungus gardens (fungus combs) of fungus-growing termites led to the discovery of characteristic ophiostomatalean-like fruiting structures. In this study, these ophiostomatalean-like fungi were identified using morphological characteristics, conventional molecular markers, and whole genome sequencing. In addition, the influence of the extracts derived from various parts of Termitomyces combs on the growth of these fungi in culture was considered. Based on phylogenomic analyses, two new genera (Intubia and Chrysosphaeria) were introduced to accommodate these ophiostomatalean species. Phylogenetic analyses revealed that the isolates resided in three well-supported lineages, and these were described as three new species (Intubia macrotermitinarum, I. oerlemansii, and Chrysosphaeria jan-nelii). Culture-based studies showed that these species do not depend on the Termitomyces comb material for growth. [ABSTRACT FROM AUTHOR]

Several species in the Euwallacea fornicatus complex have emerged as important pests of woody plants globally, particularly in habitats where they are invasive aliens. These beetles live in obligate symbioses with fungi in the genus Fusarium. In this study, we identified Euwallacea spp. and their fungal mutualists that have emerged as pests of planted Acacia crassicarpa in Riau, Indonesia. Morphological identification and phylogenetic analyses of the mitochondrial cytochrome oxidase c subunit I (COI) gene confirmed that E. similis and E. perbrevis are the most abundant beetles infesting these trees. Multilocus phylogenetic analyses of their fungal mutualists revealed their nonspecific association with six Fusarium species. These included F. rekanum and five novel Fusarium mutualists within the Fusarium solani species complex (FSSC), four of which reside in the Ambrosia Fusarium Clade (AFC). These new species are described here as F. akasia, F. awan, F. mekan, F. variasi, and F. warna. [ABSTRACT FROM AUTHOR]

During surveys of insect-associated mycobiomes in Norway, Poland, and Russia, isolates with affinity to Graphilbum (Ophiostomatales, Ascomycota) were recovered. In this study, eight known Graphilbum species as well as the newly collected isolates were compared based on morphology and DNA sequence data for four gene regions. The results revealed seven new species, described here as G. acuminatum, G. carpaticum, G. curvidentis, G. furuicola, G. gorcense, G. interstitiale, and G. sexdentatum. In addition to these species, G. crescericum and G. sparsum were commonly found in Norway. All new species were recovered from conifers in association with bark beetles, cerambycid beetles, and weevils and were morphologically similar, predominantly with pesotum-like asexual morphs. Where sexual morphs were present, these were small ascomata with short necks and rod-shaped ascospores having hyaline sheaths. The results suggest that Graphilbum species are common members of the Ophiostomatales in conifer ecosystems. [ABSTRACT FROM AUTHOR]

Fusarium circinatum L. is an important pathogen in countries that grow and manage Pinus species. Approximately 50% or 600 000 ha of South Africa's commercial plantations are planted to Pinus spp. and some of these are threatened by this fungus. Contaminated plants, planting trays, soil and water can all act as sources of inoculum. In this study, we considered the role of grasses as a possible source of inoculum for F. circinatum-associated disease of Pinus in South Africa. Isolates of F. circinatum were collected from grasses in the understories of pitch-canker affected stands of Pinus radiata D.Don and Pinus patula Schiede ex Schltdl. & Cham. in the Western Cape and Limpopo provinces, respectively. The mating types and microsatellite-based genotypes of the isolates were then compared with those in collections of this pathogen associated with pitch-canker on P. radiata and P. patula in the respective regions. The results showed that the F. circinatum isolates from grass originated from inoculum produced from stem and branch cankers on the trees above the grasses. The discovery of F. circinatum from five grass species in Limpopo increases the total number of known grasses associated with the fungus to nine in South Africa and seventeen globally. All of the F. circinatum isolates recovered from grass in South Africa displayed levels of aggressiveness to P. patula seedlings that were comparable with those of an isolate used for routine screening of commercial planting stock. The data also suggest that grass might influence the expression of disease caused by F. circinatum on Pinus. This was because a specific genotype of the pathogen originating from grass was less aggressive on P. patula seedlings than its counterpart from diseased Pinus. Taken collectively, the results indicate that phytosanitary practices for the management of F. circinatum should include grass as a significant source of inoculum, and this should be an important quarantine consideration, both nationally and internationally. [ABSTRACT FROM AUTHOR]

During a survey of putative fungal pathogens infecting oak trees in the Gangwon Province of the Republic of Korea, a fungus resembling a Ceratocystis sp. was repeatedly isolated from natural wounds on Quercus variabilis. Morphological comparisons and DNA sequence comparisons based on partial β-tubulin and TEF-1α gene regions showed that the fungus resided in a distinct lineage. This novel Ceratocystis species is described here as C. quercicola sp. nov. This is the first novel species of Ceratocystis to be reported from Korea. A pathogenicity test showed that it can cause lesions on inoculated trees but that it had a very low level of aggressiveness. The discovery of this fungus suggests that additional taxa residing in Ceratocystis are likely to be discovered in Korea in the future. [ABSTRACT FROM AUTHOR]

Eucalyptus camaldulensis can be seen as an iconic tree of superlatives. It is the eucalypt with the widest native range, and one of the most widely planted eucalypts around the globe. In South Africa, it is the most widespread and the most aggressively invasive eucalypt. It has many uses, but also causes major impacts. However, little is known about key aspects of its ecology in South Africa, including its invasion history, invasion processes and dynamics, and people's perceptions of its positive and negative effects on ecosystems. Such knowledge is crucial for developing robust and defendable guidelines for sustainable management of the species. This paper provides a comprehensive dossier of the species in South Africa. It reviews what is known of its introduction and planting history, its current distribution, its value for commercial forestry and other uses, its impacts as an invasive species, pests and pathogens associated with the species, people's perceptions of the species and conflicts of interest, and the options for management and restoration. The review reveals that E. camaldulensis is a tree of many contradictions in South Africa, making it a poster-child example of a conflict-generating non-native species. Based on available knowledge, we assess options for improved management. We highlight several knowledge gaps which need to be addressed in more detail through future research. It is hoped that this species profile will serve as a model for the types of information that are needed for developing objective management strategies for non-native tree species in different parts of the world. [ABSTRACT FROM AUTHOR]

The disease known as pitch canker results from infection of Pinus species by the fungus Fusarium circinatum. This fungus also causes a serious root disease of Pinus seedlings and cuttings in forestry nurseries. Pinus radiata and P. patula are especially susceptible to the pathogen, but there are no records of pitch canker on P. patula in established plantations. To date, only planting material of this tree species in nurseries or in plantations at the time of establishment have been infected by F. circinatum. Symptoms of pitch canker have recently emerged in an established P. patula plantation in South Africa and this study sought to determine whether the symptoms were caused by F. circinatum. Isolates from cankers were identified as F. circinatum using morphology and DNA-based diagnostic markers. Microsatellite markers were then used to determine the genetic diversity of a collection of 52 isolates. The entire population included 17 genotypes representing 30 alleles, with a greater number of genotypes collected from younger (three- to six-year-old) than older (12- to 19-year-old) trees. Both mating types of F. circinatum were present, but no evidence of sexual recombination was inferred from population genetic analyses. This is the first record globally of pitch canker on P. patula trees in managed plantations. It is of significant concern to South Africa, where P. patula is the most important Pinus species utilised for plantation forestry. [ABSTRACT FROM AUTHOR]

Uromycladium acaciae is the cause of a severe wattle rust epidemic in plantations of Acacia mearnsii (black wattle) in southern Africa. Research on the biology of this damaging rust is assisting in the development of control strategies. One strategy under investigation is the identification and deployment of resistant lines of A. mearnsii. Selection of resistant families currently relies on large-scale, time-consuming and expensive field trials. In this study, we present a detailed artificial inoculation protocol for U. acaciae, which can be used to screen for resistance. The results of an experiment that used the protocol to screen the relative resistance of 12 families of A. mearnsii to U. acaciae are also presented. The developed artificial inoculation protocol can also be used to investigate several other aspects of this host-pathogen system. [ABSTRACT FROM AUTHOR]

Vietnam and Indonesia have rapidly growing and extensive plantation forestry programs, especially of Acacia spp. and Eucalyptus spp. As these plantations expand, the threat from pests and diseases also increases. Calonectria species are among those pathogens causing diseases of trees in plantations and nurseries in these countries. Extensive surveys were conducted across plantations and nurseries of Vietnam and parts of Indonesia, where a large number of Calonectria isolates were retrieved from diseased leaves and soils associated with symptomatic trees. The aim of this study was to identify and resolve the phylogenetic relationships among these isolates using DNA sequence comparisons of four gene regions as well as morphological characters. From a collection of 165 isolates, the study revealed five known and 10 undescribed species. The relatively high diversity of Calonectria species found in this study supports the view that many more species in this genus remain to be discovered in other areas of Southeast Asia. [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]

Deladenus siricidicola is the primary biocontrol agent of the invasive woodwasp, Sirex noctilio. The nematode is mass-reared in culture on the S. noctilio symbiotic fungus, A. areolatum, but can also be induced to convert into its infective form in culture. The aim of this study was to explore the level of variation among a collection of D. siricidicola strains to convert into the infective form in culture. In addition, we measured variation in growth of the nematode on a strain of A. areolatum that is commonly used for laboratory rearing. Both traits could influence laboratory rearing and efficiency in the field. The 22 strains from three countries showed significant variation in the frequency of conversion into the infective form in culture. Even genetically uniform strains from South Africa displayed a range of variation in this trait. There was also significant variation in the growth of D. siricidicola on A. areolatum. These results emphasise the importance of considering variation in traits in D. siricidicola that could influence a biological control program. They also provide tools that could be used to screen larger collections of D. siricidicola for variation in traits linked to virulence and reproduction. [ABSTRACT FROM AUTHOR]

Plantations of Pinus spp. in Colombia are severely damaged by various phasmid (Phasmatodea: Diapheromeridae) insects. Of these, Litosermyle ocanae is one of the most serious defoliators. Since 1988, several outbreaks have been recorded in Pinus patula plantations, resulting in substantial economic losses. The aim of this study was to determine the life cycle of Litosermyle ocanae in P. patula plantations in Colombia. In addition, we assessed the population levels of L. ocanae and the presence of natural enemies of L. ocanae in these plantations. The development of L. ocanae was monitored under controlled conditions, and population fluctuations and the presence of natural enemies was assessed from field-collected eggs and field observations. The results showed a total life cycle of 225 d and 235 d for males and females, respectively, and a complete fourth instar nymph cycle of 121 d and 116 d for males and females, respectively. The sex ratio was 1:1.7 female to male. Females laid an average of 112 eggs. The number of eggs peaked in November and the most dominant natural enemy observed was a parasitoid wasp Adelphe sp. (Hymenoptera: Chrysididae). The results provide important information for the management of L. ocanae in P. patula plantations. [ABSTRACT FROM AUTHOR]

In South Africa, there is currently a phenomenon where a Eucalyptus grandis × E. urophylla clone is dying on a large scale, whereas co-occurring clones in the same plantation area remain healthy. No primary biotic pathogen has been isolated from these dying trees. However, the plantation region has endured severe drought conditions. We hypothesised that the specific E. grandis × E. urophylla clone dieback is due in part to the affected trees having an elevated drought vulnerability. We tested this hypothesis retrospectively by examining how the dying (branch dieback started) as compared with two healthy and co-occurring E. grandis × E. urophylla clones vary in branch xylem anatomy (water transport) and leaf stable carbon isotopes (gas exchange) across two levels of mean annual precipitation in the planted landscape. There was significant intra-hybrid variation in the range of studied hydraulic traits. It appeared that the dying clone is maladapted to drier field conditions relative to the two healthy growing clones. Individuals of the drought-susceptible clone had increased hydraulic conductivity, having both wider vessel lumens and larger lumen fractions, and also did not regulate leaf-level transpiration in the drier landscape as efficiently as the two unaffected clones (lower δ13C ratios). In turn, one of the healthy growing clones had a completely different hydraulic strategy, having higher wood density, lower lumen fractions, and higher δ13C ratios that are widely considered as hydraulically resilient during water stress. The other clone appeared to also gain drought tolerance via higher leaf-level water-use efficiency, although drought tolerance was less clear regarding xylem anatomy. We highlight how variation in relative drought vulnerability can be highly significant even between clones within a single hybrid group. Knowledge of this variation in plant hydraulics between commercially planted and closely related Eucalyptus trees would complement clone deployment programmes in a target landscape. [ABSTRACT FROM AUTHOR]

Euphorbia ingens, landmark succulent trees in savannas of South Africa, have been dying in large numbers over the last 10–15 years. Initial studies conducted in the Limpopo province of South Africa revealed a diverse group of biotic agents including fungi, beetles and moths associated with dying trees, but due to the limited geographic extent of these studies, it was not known if the same agents were associated with dying trees regionally. In this study, diseased and insect-infested trees were sampled for fungal pathogens and insects at six sites in four provinces located across South Africa. Fungi were identified based on morphology and DNA sequencing of the ITS, LSU, β-tubulin and TEF 1-α gene regions, and insects were identified based on morphology. Fungal isolates were identified asAureovirgo volantis,Fusarium solani,Lasiodiplodia×egyptiacae,Ophiostoma thermarumand aReaderiellaspecies. Five insects were identified, all in the family Curculionidae, including two ambrosia beetles,Cyrtogenius africusand aStenoscelisspecies. All fungi and insects collected are known to be opportunistic and occur on stressed trees as secondary agents of mortality or disease. These results suggest that the die-off is not related to attack of the trees by aggressive insects or pathogens, but rather thatE. ingensin this region is under stress from environmental factors that supports the ability of opportunistic insects and pathogens to establish. [ABSTRACT FROM PUBLISHER]

Entomopathogenic nematodes (EPNs) in the families Steinernematidae and Heterorhabditidae are obligate insect pathogens. Their favourable characteristics as biocontrol agents have resulted in some species of EPNs being released globally and widely used for the control of diverse insect pests. In this review, we consider the occurrence of currently described EPN species, including those that have been released globally for commercial purposes. We also discuss the contribution of regulation policies to the global distribution of these species and issues that influence import regulations. Possible non-target effects, the use of commercial versus native EPNs and the possible interaction between these species are considered. Finally, we provide a view as to whether existing policies adequately deal with the risks associated with the global movement of EPNs and we suggest future directions that should be considered for the use of EPNs as biological control agents. [ABSTRACT FROM AUTHOR]

Increasing incidences of drought-induced tree mortality are being recorded worldwide, including Africa. African forests cover a significant proportion of the continent, which implies that African forest sustainability is threatened from a climate-change perspective. This is especially problematic in a developing nation context, because forest ecosystems such as plantation forestry provide important goods and services that sustain human well-being and economic growth. Disentangling the likely triggers of tree mortality (including those linked to drought) in landscapes would not only explain the mechanisms underlying local die-offs, but also better predict future mortality events. Methods applied in the field of ecophysiology are particularly useful to studyin situplant responses to an environment. We consider thestatus quoof global peer-reviewed publication outputs during the past century that have made use of key ecophysiological research approaches, specifically studies concerning ‘tree xylem anatomy’, ‘tree xylem cavitation’, ‘tree leaf gas-exchange’ and ‘tree xylem hydraulic conductivity’. We highlight the growth and applicability of this research field in understanding tree ecology. We also assess the role that the forestry sector has had in promoting such research to ensure future-proof forest products. Most importantly, we consider how Africa with its vast forested landscapes fits within this research spectrum. The last decade saw an increase of up to 60% in the total number of articles published, particularly with a focus on tree xylem cavitation and conductivity. Although forest research contributed greatly to the global tally of ecophysiological studies, and such studies in Africa have also increased by up to 88% in the past decade, there remains a general lack of this research topic in the continent. It is clear an optimisation of applied ecophysiological concepts and techniques will promote an improved understanding of tree mortality patterns. We argue that ecophysiological data will be crucial to future-proof tree improvement strategies in African commodity production landscapes, especially given future drier climates. [ABSTRACT FROM AUTHOR]

In the mid-1970s, Mozambique embarked on several forestry projects to promote and establish large plantation areas with eucalypt trees. The planted species includedCorymbia citriodora,Eucalyptus camaldulensis,E. salignaandE. tereticornis. Similar to other regions of the world, pests and pathogens pose a significant threat to eucalypt plantations in Mozambique, but little is known regarding the diseases of trees in the country. The aim of this study was to provide the first detailed consideration of the possible disease problems affecting plantation- grown eucalypt species in the central and northern provinces of Mozambique. Isolates of fungal pathogens were obtained from material displaying disease symptoms collected during two field surveys conducted in 2010 and 2011. Representative fungal isolates were identified using DNA sequence data. Stem canker diseases caused by fungi in the Botryosphaeriaceae, Cryphonectriaceae and Teratosphaeriaceae, as well as leaf spots caused by species ofCalonectria,Pilidiella,PilidiumandPhakopsora myrtacearumwere commonly encountered. Their relative importance to the future of planation forestry in Mozambique is discussed. [ABSTRACT FROM PUBLISHER]

Species ofTeratosphaeriainclude some of the most important fungal pathogens of plantation-grown eucalypt trees. During routine disease surveys, symptoms and signs of leaf spot and blight were observed on the foliage of one-year-oldE. grandis×E. urophyllahybrids in the Zululand region of KwaZulu-Natal, South Africa. These were distinct from those caused by the well-known and leaf-infecting fungusTeratosphaeria suttonii, which is not considered an important pathogen in the country. Culture and morphological characteristics as well as DNA sequences for three gene regions were used to compare the fungus isolated from the newly emerging symptoms with those for knownTeratosphaeriaspecies. DNA sequences were the same as those forT. destructansand this was consistent with the distinctive morphology of the asexual spores and the symptoms on leaves.Teratosphaeria destructansis an aggressive pathogen and actions will be needed to ensure that it does not impart serious losses to the local forestry industry. [ABSTRACT FROM AUTHOR]

The diversity of Phytophthora spp. in rivers and riparian ecosystems has received considerable international attention, although little such research has been conducted in South Africa. This study determined the diversity of Phytophthora spp. within a single river in Gauteng province of South Africa. Samples were collected over 1 y including biweekly river baiting with Rhododendron indicum leaves. Phytophthora isolates were identified with phylogenetic analyses of sequences for the internal transcribed spacer (ITS) region of the ribosomal DNA and the mitochondrial cytochrome oxidase c subunit I (coxI) gene. Eight Phytophthora spp. were identified, including a new taxon, P. taxon Sisulu-river, and two hybrid species from Cooke's ITS clade 6. Of these, species from Clade 6 were the most abundant, including P. chlamydospora and P. lacustris. Species residing in Clade 2 also were encountered, including P. multivora, P. plurivora and P. citrophthora. The detection of eight species in this investigation of Phytophthora diversity in a single riparian river ecosystem in northern South Africa adds to the known diversity of this genus in South Africa and globally. [ABSTRACT FROM AUTHOR]

Zimbabwe embarked on plantingEucalyptusspecies in the early 1900s. Based on a robust breeding programme, it has become a major source of seed for other countries in and outside Africa. Tree health surveys conducted onEucalyptusin some east and southern African countries over the past two decades have revealed several important fungal diseases that were previously not known in the region, but little is known regarding these problems in Zimbabwe. The aim of this study was to identify importantEucalyptusdiseases across Zimbabwe's agroclimatic regions. Morphological characteristics and DNA sequence data were used to identify pathogens collected to species level. Widespread stem canker diseases, caused by species belonging to the Botryosphaeriaceae and Teratosphaeriaceae, and leaf spot diseases caused by fungi in the Capnodiales, were identified. Armillaria root and stem rot was restricted to a single site in the Eastern Highlands. Fungi that could cause canker or blue stain of timber were isolated from recently harvested stumps and included species ofCeratocystisandOphiostoma. This study is the first to identifyEucalyptuspathogens to species level in Zimbabwe and we report for the first time the presence of the stem canker pathogenT. gauchensisin southern Africa. The results will provide a foundation for the formulation of future disease management strategies in the country. [ABSTRACT FROM PUBLISHER]

Adelgids (Hemiptera) in the genusPineushave been reported as introduced insect pests causing serious losses toPinusplantations worldwide. In 2008,Pineus boerneriwas recorded for the first time in Colombia, with infestations noted onPinus kesiya,P. tecunumanii,P. maximinoiandP. oocarpa. The lack of information on this insect in Colombia prompted investigations of its life cycle and infestation levels as well as host susceptibility of the mainPinusspecies planted in Colombia. In addition, the possibility of using aCeraeochrysaspecies, an already established predator of adelgids in Colombia, for biological control was considered. Results showed thatPineus boerneriin Colombia has an anholocyclic life cycle comprised of four instars with a complete duration of between 49 and 97 d. Infestations were higher in the middle and upper part of trees.Pinus kesiyaandP. maximinoihad the highest levels of susceptibility in field as well as in greenhouse trials. A survey of naturally infested trees showedP. tecunumaniito be moderately susceptible, whereasP. patulaandP. oocarpahad low levels of susceptibility in a greenhouse trial but were not susceptible in the field. Investigations considering the impact of predation ofCeraeochrysaspecies showed a high predation rate of up to 140P. boernericonsumed per day by a singleCeraeochrysaindividual. Other predators ofP. boerneriwere recorded but were not sufficiently common to warrant detailed study. [ABSTRACT FROM AUTHOR]

A dramatic rise in the incidence of a serious canker and wilt disease ofAcacia mangiumhas led to the replacement of thousands of hectares of plantation forests in eastern Sabah. A disease screening program was initiated to evaluate levels of disease resistance and tolerance to the causative fungus,Ceratocystis acaciivora, in anA. mangiumbreeding population. Resistance was evaluated as the presence or absence of external symptoms in two open-pollinated progeny trials. In addition, tolerance was evaluated in one of these trials by measuring the size of lesions produced following a controlled inoculation withC. acaciivora. Heritability estimates were low to moderate for growth traits but were close to zero for the range of traits used to evaluateCeratocystisresistance and tolerance. Nevertheless, significant differences were found among the three sources (families from the local land race, Queensland and Papua New Guinea origins, all selected in progeny trials in Sabah) and among populations within these sources for many of the traits used to assess damage by the pathogen. Significant differences in lesion length among sources were evident, but no differences among populations within sources were found. Differences among sources and populations would have been reduced as seed was sourced from a progeny within provenance trial where hybridisation among origins and populations would have occurred. Results of this study suggest that modest genetic improvement may be realised from selecting among populations and sources for resistance and tolerance to this pathogen. However, the lack of additive genetic variation will make the development of resistant breeds challenging. [ABSTRACT FROM AUTHOR]

Subsequent to 1950, commercially propagated and non-native trees, includingPinus, EucalyptusandCupressusspecies in Colombian plantations, have been damaged by several native defoliating insects, residing mainly in the Lepidoptera (Geometridae), Phasmatodea (Heteronemiidae) and the Hymenoptera (Formicidae). We report on the relatively recent appearance of three important and damaging new insect pests of plantation-grownPinusandEucalyptusspp. in Colombia, two of which are not native to this country. These includeMonalonion velezangeli(Hemiptera: Miridae),Glycaspis brimblecombei(Hemiptera: Psyllidae) andPineus boerneri(Hemiptera: Adelgidae). This report provides information on the basic biology of these new pests, their hosts, areas of occurrence, likely origin and prospects for their management in the future. [ABSTRACT FROM AUTHOR]

Fusarium circinatumis an important fungal pathogen ofPinusspecies. In South Africa, it is the most significant pathogen ofPinus patulaseedlings in forestry nurseries where it presents a substantial constraint to productivity and can continue to cause mortality in-field for up to two years after establishment. This study describes the results from two trials whereP. patulaseedlings were inoculated withF. circinatumto determine the impact of the pathogen on nursery and field performance. Seedlings were also subjected to water stress treatments to ascertain whether this would trigger the onset of disease symptoms. Inoculum load and timing of inoculation had significant effects on seedling survival in both the nursery and field. High inoculum concentrations caused greater levels of mortality and, where seedlings were inoculated at a young age, they showed higher levels of susceptibility toF. circinatum. Temporary water-stress in the nursery produced smaller plants and improved in-field survival, but this treatment did not trigger higher mortality in inoculated treatments. On the other hand, transplant stress was a major contributor to the higher levels of mortality observed in inoculated treatments. Overall, these studies confirmed that infection in the nursery leads to the disease problems observed during early plant establishment in the field. [ABSTRACT FROM AUTHOR]

The pitch canker pathogen,Fusarium circinatum, has major impacts on production in pine nurseries and plantations in South Africa. Thus far, efforts to reduce local spread have focused on rouging of infected pines and sanitation to eliminate local sources of inoculum. Although the host range ofF. circinatumwas thought to be limited to pines and Douglas-fir, recent studies in California indicate that this fungus is capable of infecting grasses as a symptomless endophyte. Consequently, it is possible that grasses represent a reservoir of inoculum that influences the occurrence of disease in South African pine nurseries and plantations. The objectives of this study were to survey a wide range of grass species in both nurseries and plantations in South Africa for the presence ofF. circinatum. In all, 22 species of grass were sampled at a nursery in Mpumulanga and in a plantation on the Western Cape. Isolates obtained from grasses were identified based on morphological criteria and DNA sequence data.Fusarium circinatumwas recovered from vegetative tissues of four grass species includingBriza maxima, Ehrharta erectavar.erecta, Pentameris pallidaand one species that could not be identified. All isolates were pathogenic to pines and comparable in virulence to a knownF. circinatumisolate that was included as a positive control. These studies indicate that grasses may constitute inoculum reservoirs that could facilitate persistence and dissemination of the pathogen in nurseries, and provide a means for the pathogen to move between widely separated pine stands, where grass hosts occur in intervening areas. [ABSTRACT FROM AUTHOR]

Since the first appearance ofFusarium circinatumin South Africa in 1990, foresters have been challenged with poor field survival ofPinus patulaseedlings at establishment. One of the best long-term solutions is to improve the genetic tolerance ofP. patulato infection by the pathogen. Currently, large numbers of families are routinely screened for their tolerance toF. circinatumby infecting open-pollinated seedlings from orchard clones in a greenhouse and assessing lesion development. In this study, nine-year-oldP. patulatrees from 96 families were inoculated withF. circinatumin the field. Their levels of tolerance were assessed and compared to those observed in seedlings originating from seed harvested from the same trees. The field results were also compared with those from previous greenhouse screening trials where seedlings from a number of the same families had been inoculated withF. circinatum. The results showed that there was a strong phenotypic (r= 0.71) and genetic (rg= 0.94) correlation in the performance of the families common in both the greenhouse studies. A comparison of the tolerance of the families, screened as both seedlings and as trees, was also meaningful (r= 0.40). Furthermore, the seedlings raised from seeds collected from the infectedP. patulatrees, that ranked more tolerant than the mean of theP. elliottiitrees, were similar in tolerance toP. elliottiiseedlings in the greenhouse trial. Our results indicate that utilising seedlings from clones known to be tolerant should improve the tolerance of mature trees to infection byF. circinatum. [ABSTRACT FROM AUTHOR]

The primary symptoms associated withFusarium circinatuminfection in pine seedling nurseries are root and collar rot, shoot and tip die-back and seedling mortality. Management of this pathogen in nurseries usually involves the integration of various strategies relating to sanitation, insect control and fungicide treatment. The overall goal of this study was to use quantitative real-time PCR (qPCR) to detect and quantify the airborne inoculum ofF. circinatumin a commercial pine seedling nursery. For this purpose, an existing qPCR method was optimised and evaluated for its efficacy to quantify and monitor airborne conidia over a one-year period. Results showed thatF. circinatumoccurred at relatively low levels in the nursery throughout the year and that its distribution was spatially sporadic. The data suggest that standard nursery sanitation practices in the test nursery maintained the airborne inoculum ofF. circinatumat low levels. The uneven distribution of infection also suggests that airborne inoculum does not represent the primary source of inoculum for theF. circinatum-associated seedling disease. [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]

Ophiostoma species, some of which cause sapstain in timber and/or are mild pathogens, are common fungal associates of bark beetles (Coleoptera: Scolytinae). Three new Ophiostomataceae from Spain are recognized in the present study based on comparisons of sequence data for three gene regions as well as morphological characteristics. The new taxa are described as Ophiostoma nebulare sp. nov., Ophiostoma euskadiense sp. nov. and Graphilbum crescericum sp. nov. [ABSTRACT FROM AUTHOR]

Despite their importance in ecosystems and biodiversity, very little is known about the health of trees in the native environments of South Africa. The vision and primary goal of the Centre of Excellence in Tree Health Biotechnology (CTHB) is therefore to promote the health of native trees by making use of biotechnology. In this paper, we use the CTHB as an example to explore the positive impacts of the Department of Science and Technology's Centre of Excellence programme on the science system of South Africa and, furthermore, to consider the programme's overall contribution to the strategic priorities set out in the South African Government's Medium Term Strategic Framework that guides the national mandate. We also discuss briefly how the outputs of the CTHB are put into practice in the form of tangible services provided to stakeholders from all sectors ranging from academia, the forestry industry and the general public through to government. Finally, we consider the various factors that have contributed to the success of the CTHB and conclude with a reflection on the far-reaching effects that a relatively small investment by the Department of Science and Technology has had on research and development in South Africa. This is not only in terms of human capacity development, but also overall research excellence. For the CTHB specifically, this initiative also has facilitated a deep appreciation of the factors threatening the health of native trees. Such knowledge provides a crucial foundation towards our understanding of the challenges associated with trees in native woody ecosystems and those propagated commercially, which have emerged and will continue to emerge as a result of trade, transport and tourism, as well as climate change. [ABSTRACT FROM AUTHOR]

The genus Celoporthe was first described when C. dispersa was discovered in South Africa associated with dieback and cankers on trees in the Myrtales. Four additional species were recently described from Eucalyptus and Syzygium cumini in China as well as S. aromaticum and Eucalyptus in Indonesia. Inoculation trials have shown that all Celoporthe species, including those that have not been found on Eucalyptus species in nature, are pathogenic to Eucalyptus and they are thus potentially threatening to commercial Eucalyptus forestry. New isolates, morphologically similar to Celoporthe, have been collected from S. legatti in South Africa and S. guineense in Zambia. Multigene phylogenetic analyses based on DNA sequences of the ITS region, TEF1α gene and two areas of the β-tubulin gene revealed additional cryptic species in Celoporthe. Phylogenetic data were supported by morphological differences. These resulted in the description of two previously unknown species of Celoporthe, namely C. fontana and C. woodiana, for two of these cryptic groups, while the third group represented C. dispersa. These species all can readily infect Eucalyptus as well as several species of Syzygium, the latter of which are native to Africa. [ABSTRACT FROM AUTHOR]

Grosmannia serpens was first described from pine in Italy in 1936 and it has been recorded subsequently from many countries in both the northern and southern hemispheres. The fungus is vectored primarily by root-infesting bark beetles and has been reported to contribute to pine-root diseases in Italy and South Africa. The objective of this study was to consider the identity of a global collection of isolates not previously available and using DNA sequence-based comparisons not previously applied to most of these isolates. Phylogenetic analyses of the ITS2-LSU, actin, beta-tubulin, calmodulin and translation elongation factor-1 alpha sequences revealed that these morphologically similar isolates represent a complex of five cryptic species. Grosmannia serpens sensu stricto thus is redefined and comprises only isolates from Italy including the ex-type isolate. The ex-type isolate of Verticicladiella alacris was shown to be distinct from G. serpens, and a new holomorphic species, G. alacris, is described. The teleomorph state of G. alacris was obtained through mating studies in the laboratory, confirming that this species is heterothallic. Most of the available isolates, including those from South Africa, USA, France, Portugal and some from Spain, represent G. alacris. The remaining three taxa, known only in their anamorph states, are described as the new species Leptographium gibbsii for isolates from the UK, L. yamaokae for isolates from Japan and L. castellanum for isolates from Spain and the Dominican Republic [ABSTRACT FROM AUTHOR]

Gondwanamyces and its Custingophora anamorphs were first described from Protea infructescences in South Africa. Subsequently these unusual fungi were also found on Cecropia in Central America. During all investigation into the decline and death of native Euphorbia trees in South Africa, several fungal isolates resembling the anamorph state of Gondwanamyces were obtained from diseased tissues. In this study these isolates are identified based on morphology and comparisons of DNA sequences. Two previously unknown Gondwanamyces species were identified, both were associated with damage caused by beetles (Cossonus sp.). Inoculation studies showed that the new species of Gondwanamyces are pathogenic on Euphorbia ingens and may contribute to the decline of these trees. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

There have been several recent reports of Pterocarpus angolensis (kiaat) trees dying in South Africa, Zambia and Zimbabwe, where this tree is used in traditional medicine and is a valuable source of timber for woodcarving and furniture. A survey of material from diseased P. angolensis trees in South Africa yielded isolates of the Botryosphaeriaceae, an important fungal family known to cause a number of tree diseases. The aim of this study was to identify these Botryosphaeriaceae and to determine their pathogenicity to P. angolensis with branch inoculations. Seven species of the Botryosphaeriaceae were identified based on a combination of morphological characteristics and sequences from the ITS and EF-1α gene regions. Four of these represent undescribed taxa for which the names Pseudofusicoccum violaceum, P. olivaceum, Diplodia alatafructa and Fusicoccum atrovirens are provided. The remaining three species collected include Lasiodiplodia theobromae, L. pseudotheobromae and L. crassispora. Inoculation trials on tree branches showed that L. pseudotheobromae and one isolate of D. alatafructa differed significantly from control inoculations. The high levels of virulence and common occurrence of L. pseudotheobromae suggest that this species could play a role in tree dieback and death. [ABSTRACT FROM AUTHOR]

Leptographium species provide an ideal model to test the applications of a PCR microcoding system for differentiating species of other genera of ascomycetes. Leptographium species are closely related and share similar gross morphology. Probes designed for a PhyloChip for Leptographium have been transferred and tested as primers for PCR diagnostic against Leptographium species. The primers were combined with complementary universal primers to identify known and suspected undescribed species of Leptographium. The primer set was optimized for 56 species, including the three varieties of L. wageneri, then blind-tested against 10 random DNA samples. The protocols established in this study successfully identified species from the blind test as well as eight previously undescribed isolates of Leptographium. The undescribed isolates were identified as new species of Leptographium with the aid of the microcoding PCR identification system established in this study. The primers that were positive for each undescribed isolate were used to determine close relatives of these species and some of their biological characteristics. The transfer of oligonucleotides from a micro-array platform to a PCR diagnostic was successful, and the identification system is robust for both known and unknown species of Leptographium. [ABSTRACT FROM AUTHOR]

The taxonomy of Armillaria in southern South America has received little attention since the work of Singer and others. In this study we examine the morphological traits and cultural features for taxa representing the lineages revealed based on molecular phylogenyi and we link them to previously described taxa based on morphology. Lineages I-IV were identified as Armillaria novae-zelandiae, A. montagnei, A. umbrinobrunnea comb. nov. and A. sparrei respectively. They could be differentiated morphologically based on dimension, features of the epicutis, annulus, stipe, hymenophoral trama and flavor and characteristics in culture. Furthermore there was no evidence of host preference for the species recognized. This is the first study integrating the phylogeny and morphology of Armillaria species from Patagonia, and it provides a foundation for future research on these fungi in South America. [ABSTRACT FROM AUTHOR]

Neofusicoccum parvum and N. ribis are closely related species whose identities often have been confused. These fungal plant pathogens were identified recently as the most abundant species of Botryosphaeriaceae (Ascomycetes) isolated from native Syzygium cordatum trees in South Africa. In another study using multiple gene genealogies from five nuclear loci three undescribed cryptic phylogenetic species as well as N. parvum were identified among 30 of these isolates. The aim of this study was to clarify the identity of the remaining isolates in the N. parvum/N. ribis complex from S. cordatum in South Africa, to describe newly identified cryptic species and to test their pathogenicity. Based on the RNA polymerase II subunit (RPB2) sequence comparisons, the isolates were identified as N. parvum or one of three previously recognized phylogenetic species that are described here as N. cordaticola, N. kwambonambiense and N. umdonicola. These species cannot be separated a priori based on morphological characteristics, although a posteriori analysis of variance showed that the differences in conidial length and width between the species were statistically significant. The isolates of the newly described species as well as N. parvum and N. ribis were tested for pathogenicity on S. cordatum under greenhouse conditions. Isolates representing the three new species were significantly more aggressive than N. parvum and N. ribis with N. kwambonambiense being the most aggressive. This study resolved long-standing questions of identity of species within N. parvum/N. ribis complex and lays a foundation for filrther studies on this group of pathogens. [ABSTRACT FROM AUTHOR]

After recent changes to the taxonomy of the Botryosphaeriaceae species with diplodia-like (= dark, ovoid, often pigmented) conidia are considered to belong to at least three genera including Diplodia, Lasiodiplodia and Dothiorella. In a recent molecular phylogenetic study it became apparent that two groups of isolates with diplodia-like conidia required taxonomic revision. One group of isolates originated from Cupressus sempervirens in Greece and Cyprus and had been identified as D. pinea f. sp. cupressi based on morphological characteristics. The other isolates originated from a Casuarina sp. in Australia and were superficially similar to those in the first group based on their morphologically similar diplodia-like conidia. The aim of this study was to resolve the taxonomy of these two groups of isolates by combining the information from the multiple gene genealogies with morphological characters. The results showed that the isolates from C. sempervirens in Greece and Cyprus represent D. cupressi. The isolates from Casuarina in Australia belong to the more distantly related genus Dothiorella and represent a distinct species that is described here as Do. casuarini sp. nov. [ABSTRACT FROM AUTHOR]

In this study seven new species of the Botryosphaeriaceae are described from baobab (Adansonia gibbosa) and surrounding endemic tree species growing in the Kimberley region of northwestern Australia. Members of the Botryosphaeriaceae were predominantly endophytes isolated from apparently healthy sapwood and bark of endemic trees; others were isolated from dying branches. Phylogenetic analyses of ITS and EF1-α sequence data revealed seven new species: Dothiorella longicollis, Fusicoccum ramosum, Lasiodiplodia margaritacea, Neoscytalidium novaehollandiae, Pseudofusicoccum adansoniae, P. ardesiacum and P. kimberleyense. [ABSTRACT FROM AUTHOR]

Sporothrix, one of the anamorph genera of Ophiostoma, includes the important human pathogen S. schenckii and various fungi associated with insects and sap stain of wood. A survey of fungi from wood utility poles in South Africa yielded two distinct groups of Sporothrix isolates from different geographical areas. DNA sequence and morphological data derived in this study showed that isolates in these groups represent two novel species in the S. schenckii-O. stenoceras species complex. A new species isolated from pine poles and rosebush wood and phylogenetically closely related to S. pallida is described here as Sporothrix stylites. Phylogenetic analyses also confirmed the synonymy of S. albicans and S. nivea with S. pallida. Sporothrix stylites and S. pallida also are related closely to the isolates from soil, previously treated as "environmental" isolates of S. schenckii. Soil isolates are clearly distinct from human isolates of S. schenckii. We describe the former here as Sporothrix humicola. The isolates from eucalypt poles group peripheral to most other species in the S. schenckii-O. stenoceras complex and are newly described as Sporothrix lignivora. Phylogenetic analyses of sequences of isolates from soil and wood together with those of clinical isolates showed that the human-pathogenic strains form an aggregate of several cryptic species. [ABSTRACT FROM AUTHOR]

Ophiostoma (Ophiostomatales) represents a large genus of fungi mainly known from associations with bark beetles (Curculionidae: Scolytinae) infesting conifers in the northern hemisphere. Few southern hemisphere native species are known, and the five species that consistently occur in the infructescences of Protea spp. in South Africa are ecologically unusual. Little is known about the vectors of Ophiostoma spp. from Protea infructescences, however recent studies have considered the possible role of insects and mites in the distribution of these exceptional fungi. In this study we describe a new species of Ophiostoma and a new Sporothrix spp. with affinities to Ophiostoma, both initially isolated from mites associated with Protea spp. They are described as Ophiostoma gemellus sp. nov. and Sporothrix variecibatus sp. nov. based on their morphology and comparisons of DNA sequence data of the 28S ribosomal, β-tubulin and internal transcribed spacer (ITS1, 5.8S, ITS2) regions. DNA sequences of S. variecibatus were identical to those of a Sporothrix isolate obtained from Eucalyptus leaf litter in the same area in which S. vanecibatus occurs in Protea infructescences. Results of this study add evidence to the view that mites are the vectors of Ophiostoma spp. that colonize Protea infructescences. They also show that DNA sequence comparisons are likely to reveal additional cryptic species of Ophiostoma in this unusual niche. [ABSTRACT FROM AUTHOR]

The majority of Mycosphaerella species from eucalypts (Eucalyptus, Corymbia and Angophora) in Australia have been recorded only from trees growing in plantations. This illustrates a bias in research in the past two decades toward commercial enterprise, and it emphasises a lack of understanding of the occurrence of these important fungi under natural conditions. Smweys of foliar fungi in native forests in eastern Australia, as well as adjacent plantations, thus have been initiated in recent years. In this study we describe four new species of Mycosphaerella from Eucalyptus spp. as well as other Myrtaceae. Mycosphaerella tumulosa sp. nov. (anamorph: Pseudocercospora sp.) was found on more than seven species of Eucalyptus and Corymbia in native forests and plantations in northeastern New South Wales and southeastern Queensland and appears to be relatively common, although not damaging to these trees. Mycosphaerella multiseptata sp. nov. was recorded from several locations on species of Angophora in native forests and amenity plantings. Mycosphaerella pseudovespa sp. nov. was found in one location in native forest on E. biturbinata. The first species of Mycosphaerella to be described from Syncarpia, M. syncarpiae sp. nov., was found in native forests in numerous locations from Sydney through to northeastern New South Wales and appears to be relatively common. [ABSTRACT FROM AUTHOR]

Botryosphaeria rhodina (anamorph Lasiodiplodia theobromae) is a common endophyte and opportunistic pathogen on more than 500 tree species in the tropics and subtropics. During routine disease surveys of plantations in Australia and Venezuela several isolates differing from L. theobromae were identified and subsequently characterized based upon morphology and ITS and EFI-α nucleotide sequences. These isolates grouped into three strongly supported clades related to but different from the known laxa, B. rhodina and L. gonubiensis, These have been described here as three new species L. vrnezuelensis sp. nov., L. crassifora sp. nov. and L. rubropurpurea sp. nov. The three could he distinguished easily from each other and the two described species of Lasiodiplodia, thus confirming phylogenetic separations. Furthermore all live Lasiodiplodia spp. now recognized separated from Diplodia spp. and Dothiorella spp. with 100% bootstrap support. [ABSTRACT FROM AUTHOR]