Five new species of the Botryosphaeriaceae from Acacia karroo in South Africa

The Botryosphaeriaceae represents an important, cosmopolitan family of latent pathogens infecting woody plants. Recent studies on native trees in southern Africa have revealed an extensive diversity of species of Botryosphaeriaceae, about half of which have not been previously described. This study adds to this growing body of knowledge, by discovering five new species of the Botryosphaeriaceae on Acacia karroo, a commonly occurring native tree in southern Africa. These species were isolated from both healthy and diseased tissues, suggesting they could be latent pathogens. The isolates were characterized based on their morphology and compared to other species for which DNA sequence data are available, in phylogenetic analyses based on the ITS, TEF-1α, β-tubulin and LSU gene regions. The five new species were described as Diplodia allocellula, Dothiorella dulcispinae, Do. brevicollis, Spencermartinsia pretoriensis and Tiarosporella urbis-rosarum. Evidence emerging from this study suggests that many more species of the Botryosphaeriaceae remain to be discovered in the southern Africa.Members of the Tree Protection Cooperative Programme (TPCP), the DST/NRF Centre of Excellence in Tree Health Biotechnology (CTHB) and the University of Pretoria, South Africa.http://www.cryptogamie.com/pagint_en/recherche/affich_sommaire.php?cnumero=65hb201

Botryosphaeriaceae species overlap on four unrelated, native South African hosts

Botryosphaeriaceae represents an important and diverse family of latent fungal pathogens of woody plants. We address the question of host range of these fungi by sampling leaves and branches of four native South African trees, including Acacia karroo (Fabaceae), Celtis africana (Cannabaceae), Searsia lancea (Anacardiaceae), and Gymnosporia buxifolia (Celastraceae).Twonew species of the Botryosphaeriaceae, namely Tiarosporella africana sp. nov. and Aplosporella javeedii sp. nov. were identified, together with fiveknown species, including Neofusicoccum parvum, Neofusicoccum kwambonambiense, Spencermartinsia viticola, Diplodia pseudoseriata, and Botryosphaeria dothidea. Most Botryosphaeriaceae occurred on more than one host. With the exception of S. lancea, which was infected by A. javeedii all the hosts were infected by more than one Botryosphaeriaceae species. Collectively, the results suggest that some intrinsic host factors, possibly combined with local environmental conditions, affect the distribution and co-infectivity of various hosts by the Botryosphaeriaceae. This would counteract the general ability of a species in the Botryosphaeriaceae to infect a broad range of plants. The combination of host and environmental factors might also explain why some Botryosphaeriaceae with apparently broad host ranges, are found on different suites of hosts in different areas of the world.Tree Protection Cooperative Programme (TPCP), the DST/NRF Centre of Excellence in Tree Health Biotechnology (CTHB) and the University of Pretoria, South Africa.http://www.elsevier.com/locate/funbiohb201

New Botryosphaeriales on native red milkwood (Mimusops caffra)

Fungi in the Botryosphaeriales (Ascomycetes) are common endophytes in woody plants with a wide global distribution and in some cases they are important tree pathogens. The aim of this study was to consider the possible cause of die-back on native coastal red milkwood (Mimusops caffra) trees growing on the east coast of South Africa. Samples were taken from symptomatic tissue and isolations were made. The resulting isolates were identified based on DNA sequence data from the rDNA-ITS, translation elongation factor 1-α and β-tubulin loci. Two new species in the Botryosphaeriales, namely Neofusicoccum variabile sp. nov. and Pseudofusicoccum africanum sp. nov., were found together with an isolate of N. mangroviorum. Neofusicoccum mangroviorum produced significantly longer lesions than the other two species and the control inoculations in pathogenicity tests and it appears to be the cause of the die-back disease.Members of the Tree Protection Cooperative Programme (TPCP), the DST/NRF Centre of Excellence in Tree Health Biotechnology (CTHB) and the University of Pretoria, South Africa.http://link.springer.com/journal/133132019-09-01hj2018BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Host specificity of co-infecting Botryosphaeriaceae on ornamental and forest trees in the Western Balkans

The Botryosphaeriaceae is a diverse family of endophytes and fungal pathogens of mainly woody plants. We considered the host range and distribution of these fungi by sampling diseased ornamental and forest trees and shrubs in Serbia, Montenegro, Bosnia and Herzegovina, spanning a Mediterranean and a Continental climatic region. In total, ten Botryosphaeriaceae species were identified in the Western Balkans and with the exception of Sphaeropsis visci and Phaeobotryon cupressi, which occurred on one host, all the species had a broader host range. Phaeobotryon cupressi was found only in the Mediterranean region and S. visci, Dothiorella sp., Dothiorella sarmentorum and Diplodia seriata were present only in the Continental region. Pathogenicity tests were conducted on a variety of hosts from which the Botryosphaeriaceae species were isolated. These included leaves and/or stems of seedlings of 21 hosts, and cut leaves and/or branches of six hosts. Moreover, stems of seedlings of Chamaecyparis lawsoniana, Cedrus deodara, Picea omorika, Pinus patula and Eucalyptus grandis were inoculated as hosts from which some or all of the Botryosphaeriaceae species used for inoculation were not isolated. Inoculations showed that the majority of these fungi could also co-infect hosts other than those from which they were isolated. The results suggest that most of the species have broad host ranges and can potentially cause disease on a broad range of tree species under certain conditions.Members of Tree Protection Co-operative Programme (TPCP), the University of Pretoria, South Africa and the Ministry of Education, Science and Technological Development of the Republic of Serbia (TR37008 and III43007). The first author also wishes to acknowledge partial financial support from European Cooperation in Science and Technology (COST) Actions Pathway Evaluation in Pest Risk Management In Transport (PERMIT FP1002), ALIEN Challenge (TD1209) and A global network of nurseries as early warning system against alien tree pests (Global Warning FP1401).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1439-03292019-04-01hj2018Forestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

New and unexpected host associations for Diplodia sapinea in the Western Balkans

Diplodia sapinea is an important pathogen of pine trees in plantations and urban areas in many parts of the world. This pathogen has recently also been isolated from diseased Cedrus atlantica, C. deodara and Picea omorika planted as ornamentals across the Western Balkans. The aim of this study was to consider the host range of D. sapinea in Serbia and Montenegro. Diplodia sapinea was identified from a broader collection of Botryosphaeriaceae from the Western Balkans region, based on the DNA sequence data for the internal transcribed spacer (ITS) rDNA and the translation elongation factor 1α (TEF 1- α). The D. sapinea isolates were obtained from sixteen tree species in the genera Abies, Cedrus, Chamaecyparis, Juniperus, Picea, Pinus, Pseudotsuga and Fagus. Four species represented new hosts in the Balkans, and this is the first report of D. sapinea from F. sylvatica anywhere in the world. Pathogenicity tests were conducted on the tree hosts from which D. sapinea was isolated, as well as on P. abies, Thuja occidentalis, Prunus laurocerasus, Eucalyptus grandis and P. patula. Inoculations were made on seedlings in the field, in the greenhouse or on freshly detached branches. Inoculations on P. pungens, P. omorika, P. abies, P. menziesii, A. concolor, P. nigra and P. sylvestris resulted in death of the seedlings 5–16 weeks after inoculation. Diplodia sapinea produced lesions on J. horizontalis and P. patula seedlings and F. sylvatica cut branches. Reciprocal inoculations showed that D. sapinea is not a pine-specific pathogen, causing disease on tree species, including those from which it had not been isolated. Not surprisingly, the pathogen was most aggressive on some species of Pinaceae.The Tree Protection Co-operative Programme (TPCP), the University of Pretoria, South Africa, and the Ministry of Education and Science of the Republic of Serbia (TR37008). The first author also wishes to acknowledge partial financial support from European Cooperation in Science and Technology (COST) Action Pathway Evaluation and Pest Risk Management In Transport (PERMIT FP1002), ALIEN Challenge (TD1209) and A Global Network of nurseries as early warning system against alien tree pests (Global Warning FP1401).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1439-03292018-06-30hj2017Forestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Botryosphaeriaceae associated with the die-back of ornamental trees in the Western Balkans

Extensive die-back andmortality of various ornamental trees and shrubs has been observed in parts of the Western Balkans region during the past decade. The disease symptomshave been typical of those caused by pathogens residing in the Botryosphaeriaceae. The aims of this study were to isolate and characterize Botryosphaeriaceae species associated with diseased ornamental trees in Serbia, Montenegro, Bosnia and Herzegovina. Isolates were initially characterized based on the DNA sequence data for the internal transcribed spacer rDNA and six major clades were identified. Representative isolates from each clade were further characterized using DNA sequence data for the translation elongation factor 1-alpha, b-tubulin-2 and large subunit rRNA gene regions, as well as the morphology of the asexualmorphs.Ten species of theBotryosphaeriaceae were identified of which eight, i.e., Dothiorella sarmentorum, Neofusicoccum parvum, Botryosphaeria dothidea, Phaeobotryon cupressi, Sphaeropsis visci, Diplodia seriata, D. sapinea and D. mutila were known taxa. The remaining two species could be identified only as Dothiorella spp. Dichomera syn-asexual morphs of D. sapinea, Dothiorella sp. 2 and B. dothidea, aswell as unique morphological characters for a number of the known species are described. Based on host plants and geographic distribution, the majority of Botryosphaeriaceae species found represent new records. The results of this study contribute to our knowledge of the distribution, host associations and impacts of these fungi on trees in urban environments.Tree Protection Co-operative Programme (TPCP), the University of Pretoria (South Africa) and the Ministry of Education and Science of the Republic of Serbia (TR37008).http://link.springer.com/journal/104822017-04-30hb2016Forestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Shot hole disease on Prunus laurocerasus caused by Neofusicoccum parvum in Serbia

Between 2010-2014 symptoms of a shot hole disease were observed on cherry laurel (Prunus laurocerasus L.) trees and shrubs in parks and other public plantings in Belgrade, Serbia. Ten symptomatic leaves were collected from each of the diseased plants and the associated fungus isolated and identified using multi-gene phylogenetic analyses and asexual morphological characters. The pathogen was identified as Neofusicoccum parvum. The same symptoms were produced when the pathogen was inoculated on test plants. To the best of our knowledge, this is the first report of N. parvum causing shot hole disease on P. laurocerasus.Tree Protection Co-operative Programme (TPCP), the University of Pretoria (South Africa), the Ministry of Education and Science of the Republic of Serbia (TR37008), European Cooperation in Science and Technology (COST) Actions Pathway Evaluation in Pest Risk Management In Transport (PERMIT FP1002) and A global network of nurseries as early warning system against alien tree pests (Global Warning FP1401).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1439-03292017-12-31hb2017Microbiology and Plant Patholog

Temporal and spatial variation of Botryosphaeriaceae associated with Acacia karroo in South Africa

The Botryosphaeriaceae are common and diverse members of fungal communities infecting woody plants. They are also increasingly being used as model organisms to understand patterns in the global movement of latent pathogens. The aim of this study was to consider the species richness of the Botryosphaeriaceae associated with the native Acacia (Vachellia) karroo across South Africa, and the variation of species at specific local sites over time. The diversity of these fungi associated with different tissues of this host plant was also considered. These questions were addressed by sampling healthy A. karroo from 23 sites in South Africa and by more intensive hierarchical sampling conducted at 40 sites in one area over 3 yr. In total, 13 species of the Botryosphaeriaceae were identified, including seven that were isolated only from the more intensively sampled area. There was a clear geographical influence, with some species occurring only in some parts of the country. Significant variation in the species richness over time for the intensively sampled area was found and there was no evidence of tissue specificity for this group of fungi in leaves, branches and branchlets. Results of pathogenicity trials showed highly variable lesion sizes for the isolated species in comparison to the control, with Sphaeropsis variabilis, Lasiodiplodia theobromae and Neofusicoccumaustrale being the most pathogenic. The overall results revealed a rich diversity of Botryosphaeriaceae on this native host, which varied significantly both geographically and on individual trees, even in the absence of obvious disease.Members of the Tree Protection Cooperative Programme (TPCP), the DST/ NRF Centre of Excellence in Tree Health Biotechnology (CTHB) and the University of Pretoria, South Africa.http://www.elsevier.com/locate/funeco2016-06-30hb201

Australian cultures of Botryosphaeriaceae held in Queensland and Victoria plant pathology herbaria revisited

The Botryosphaeriaceae is one of the most widespread and cosmopolitan endophytic group of fungi. However, the species of this group can cause severe disease when the hosts are under stressful conditions. The aim of this study was to identify living cultures from the Botryosphaeriaceae family preserved in the Queensland and Victorian Plant Pathology Herbaria using DNA sequence analyses. The 51 isolates were collected between 1971 and 2017, from 35 different host genera, with the dominant host genera being Mangifera (11 isolates), Acacia (10), and Persea (5). Multilocus sequence analyses resulted in the re-identification of 41 isolates to the genera Botryosphaeria (2 isolates), Diplodia (4), Dothiorella (1), Lasiodiplodia (19), and Neofusicoccum (15), as well as some that belonged to genera outside of the Botryosphaeriaceae (10). New records for Australia were Botryosphaeria sinensis, Diplodia alatafructa, Lasiodiplodia gonubiensis, Neofusicoccum cryptoaustrale, and N. mangroviorum. These were identified as a result of a workshop organised by the Subcommittee on Plant Health Diagnostics. The results of this study provide the fundamental information regarding the diversity of Botryosphaeriaceae species present in Australian.Plant Health Australia (PHA) who provided funds for the workshop on the identification and classification of Botryosphaeriaceae species. PHA sourced funding from the Department of Agriculture and Water Resources through a grant from the Modern Diagnostics initiative.http://link.springer.com/journal/133132020-01-01hj2019Forestry and Agricultural Biotechnology Institute (FABI

Confronting the constraints of morphological taxonomy in the Botryosphaeriales

Identification of fungi and the International Code of Nomenclature underpinning this process, rests strongly on the characterisation of morphological structures. Yet, the value of these characters to define species in many groups has become questionable or even superfluous. This has emerged as DNA-based techniques have increasingly revealed cryptic species and species complexes. This problem is vividly illustrated in the present study where 105 isolates of the Botryosphaeriales were recovered from both healthy and diseased woody tissues of native Acacia spp. in Namibia and South Africa. Thirteen phylogenetically distinct groups were identified based on Internal Transcribed Spacer (ITS) rDNA PCR-RFLP and translation elongation factor 1-α (TEF1-α) sequence data, two loci that are known to be reliable markers to distinguish species in the Botryosphaeriales. Four of these groups could be linked reliably to sequence data for formerly described species, including Botryosphaeria dothidea, Dothiorella dulcispinae, Lasiodiplodia pseudotheobromae and Spencermartinsia viticola. Nine groups, however, could not be linked to any other species known from culture and for which sequence data are available. These groups are, therefore, described as Aplosporella africana, A. papillata, Botryosphaeria auasmontanum, Dothiorella capri-amissi, Do. oblonga, Lasiodiplodia pyriformis, Spencermartinsia rosulata, Sphaeropsis variabilis and an undescribed Neofusicoccum sp. The species described here could not be reliably compared with the thousands of taxa described in these genera from other hosts and regions, where only morphological data are available. Such comparison would be possible only if all previously described taxa are epitypified, which is not a viable objective for the two families, Botryosphaeriaceae and Aplosporellaceae, in the Botryosphaeriales identified here. The extent of diversity of the Botryosphaeriales revealed in this and other recent studies is expected to reflect that of other undersampled regions and hosts, and illustrates the urgency to find more effective ways to describe species in this, and indeed other, groups of fungi.THRIP initiative of the Department of Trade and Industry, DST/NRF Centre of Excellence in Tree Health Biotechnology (CTHB), (DST) and National Research Foundation (NRF).http://www.persoonia.orghttp://www.ingentaconnect.com/content/nhn/pimjtm201