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Micrographs of Dothiorella dulcispinae. 1. Culture morphology on MEA; 2. Pycnidium (scale bar = 100 µm); C. Longitudinal section through pycnidium (scale bar = 100 µm); 4–6. Conidia and conidiogenous cells (scale bar = 10 µm), 7–8. Conidia (scale bar = 10 µm); 9. Chlamydospore (scale bar = 10 µm).
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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 discove...
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... However, pathogenicity was not tested, so the biology and potential aggressiveness of the isolates remain obscure. Also in the case of the study by Jami et al. (2012), who described D. allocellula from healthy tissues of Acacia karroo, and Pan et al. (2019), who described D. quercicola from branches of Quercus variabilis with symptoms of canker and dieback disease did not perform pathogenicity assays. Thus, pathogenicity of D. allocellula and D. quercicola could not be resolved. ...
Scientific names are crucial for communicating knowledge concerning fungi and fungus-like organisms. In plant pathology, they link information regarding biology, host range, distribution and potential risk to agriculture and food security. In the past, delimitation among pathogenic taxa was primarily based on morphological characteristics. Due to distinct species sharing overlapping characteristics, the morphological identification of species is often neither straightforward nor reliable. Hence, the phylogenetic species concept based on molecular phylogenetic reconstructions gained importance. The present opinion discusses what a fungal species is and how identification of species in plant pathology has changed over the past decades. In this context, host-specialization and species complexes are discussed. Furthermore, species concepts in plant pathology are examined using case studies from Bipolaris, Colletotrichum, Curvularia, Diaporthe, Diplodia, Meliola, Plasmopara, rust fungi and Trichoderma. Each entry contains a brief introduction to the genus, concepts used in species identification so far and the problems in describing a species followed by recommendations. The importance of correctly naming and identifying a species is addressed in the context of recent introductions, and we also discuss whether the introduction of new species in pathogenic genera has been overestimated. We also provide guidelines to be considered when introducing a new species in a plant pathogenic genus.
... brevicollis (av. = 23.4 × 10.5 mm; L/W = 2.2)(Jami et al. 2012). On ITS it differs two nucleotides from Do. brevicollis and Do. ...
The Botryosphaeriales (Dothideomycetes) includes numerous endophytic, saprobic, and plant pathogenic species associated with a wide range of symptoms, most commonly on woody plants. In a recent phylogenetic treatment of 499 isolates in the culture collection (CBS) of the Westerdijk Institute, we evaluated the families and genera accommodated in this order of important fungi. The present study presents multigene phylogenetic analyses for an additional 230 isolates, using ITS, tef1, tub2, LSU and rpb2 loci, in combination with morphological data. Based on these data, 58 species are reduced to synonymy, and eight novel species are described. They include Diplodia afrocarpi (Afrocarpus, South Africa), Dothiorella diospyricola (Diospyros, South Africa), Lasiodiplodia acaciae (Acacia, Indonesia), Neofusicoccum podocarpi (Podocarpus, South Africa), N. rapaneae (Rapanea, South Africa), Phaeobotryon ulmi (Ulmus, Germany), Saccharata grevilleae (Grevillea, Australia) and S. hakeiphila (Hakea, Australia). The results have clarified the identity of numerous isolates that lacked Latin binomials or had been deposited under incorrect names in the CBS collection in the past. They also provide a solid foundation for more in-depth future studies on taxa in the order. Sequences of the tef1, tub2 and rpb2 genes proved to be the most reliable markers. At the species level, results showed that the most informative genes were inconsistent, but that a combination of four candidate barcodes (ITS, tef1, tub2 and rpb2) provided reliable resolution. Furthermore, given the large number of additional isolates included in this study, and newly generated multigene DNA datasets, several species could also be reduced to synonymy. The study illustrates the value of reassessing the identity of older collections in culture collections utilising modern taxonomic frameworks and methods.
Citation: Zhang W, Groenewald JZ, Lombard L, et al. 2021. Evaluating species in Botryosphaeriales. Persoonia 46: 63–115.
https://doi.org/10.3767/persoonia.2021.46.03.
... anigozanthi, N. arachidis-hypogaeae, N. gossypiicola, N. infossa and N. quercina) having N. infossa as the type (Chen et al. 2015). Subsequently, N. macrospora, N. multilocularis, N. pruni, N. raii, N. variabilis and N. spiraeae were introduced (Jami et al. 2012, Abdollahzadeh et al. 2014, Slippers et al. 2014, Abdel-Wahab et al. 2017, Hou et al. 2020). Currently, a total of 21 Nothophoma species have been registered in Index Fungorum (2021). ...
Chinese Jujube (Ziziphus jujuba) is a common fruit tree used in landscaping, medicine and timber. However, Jujube trees are threatened by various pathogens in the process of planting and cultivation. In this study, destructive canker diseases of Z. jujuba were investigated in Beijing, China. Based on morphological comparison and DNA sequence analysis, the causal organisms of these diseases were identified as Dothiorella acericola and Nothophoma spiraeae. This is the first report of D. acericola and N. spiraeae on Z. jujuba. This study improves our understanding of fungal species causing canker or dieback disease on this economically important tree and provides insights on selecting the effective disease management strategies for Z. jujuba in China.
... On wheat, it causes the economically important disease known as white grain disorder (Thynne et al. 2015). Several studies have reported this genus on woody hosts as a saprobe (Jami et al. 2012Dissanayake et al. 2016 White grain disorder shrivels and discolours (white to light grey) wheat grain (Thynne et al. 2015). Affected grains are more brittle and can break during harvesting. ...
This is a continuation of a series focused on providing a stable platform for the taxonomy of phytopathogenic fungi and organisms. This paper focuses on 25 phytopathogenic genera: Alternaria, Capnodium, Chaetothyrina, Cytospora, Cyphellophora, Cyttaria, Dactylonectria, Diplodia, Dothiorella, Entoleuca, Eutiarosporella, Fusarium, Ilyonectria, Lasiodiplodia, Macrophomina, Medeolaria, Neonectria, Neopestalotiopsis, Pestalotiopsis, Plasmopara, Pseudopestalotiopsis, Rosellinia, Sphaeropsis, Stagonosporopsis and Verticillium. Each genus is provided with a taxonomic background, distribution, hosts, disease symptoms, and updated backbone trees. A new database (Onestopshopfungi) is established to enhance the current understanding of plant pathogenic genera among plant pathologists.
... DNA sequences were generated for the internal transcribed spacer region of the ribosomal RNA (rRNA) operon amplified with primers ITS-1F (Gardes and Bruns, 1993) and ITS-4 (White et al., 1990), the translation elongation factor 1-α (TEF1-α) gene amplified with primers EF1-728F and EF1-986R (Carbone and Kohn, 1999), as well as the β-tubulin (TUB2) gene amplified with primers BT2a and BT2b (Glass and Donaldson, 1995). The conditions for the PCR and DNA sequencing were the same as those described by Jami et al. (2012). ...
Acacia koa and A. heterophylla are commonly occurring native trees on the Hawaiian Islands and La Réunion, respectively. A recent phylogenetic study suggested that A. heterophylla renders A. koa paraphyletic, and that the former likely arose from the Hawaiian Islands around 1.4 million years ago. An intriguing question is whether their microbiota is similar, although they occur naturally in two very distant geographical locations. In this study, we compared the fungi in the Botryosphaeriaceae isolated from natural populations of A. koa and A. heterophylla. These fungi were chosen because they commonly occur on woody plants and some are important pathogens. They are also known to have been moved globally on asymptomatic plant materials. Isolates were identified based on comparisons of DNA sequence data for the rDNA-ITS, TEF1-α and β-tubulin loci. Ten Botryosphaeriaceae species were identified, of which four species were specific to A. koa from the Hawaiian Islands and five to A. heterophylla in La Réunion. Only one species, Neofusicoccumparvum, which is known to have a wide global distribution, was common to both hosts. The overall results of this study suggest that although A. koa and A.heterophylla share a recent evolutionary history, they have established independent microbiota, at least in terms of the Botryosphaeriaceae.
... Non-native Botryosphaeriaceae species are causing stem cankers of Eucalyptus (Gezahgne, Roux, Slippers, Wingfield, & Hare, 2004;Slippers et al., 2004) and two other species are associated with stem cankers and major dieback to the silk tree G. robusta in East Africa ( Njuguna et al., 2011). Some Botryosphaeriaceae species are latent pathogens infecting a wide range of hosts from planted Pinus spp. to indigenous Acacia and others, thus raising concerns on imminent diseases of important indigenous species caused by Botryosphaeriaceae (Jami, Slippers, Wingfield, & Gryzenhout, 2012;Jami, Wingfield, Gryzenhout, & Slippers, 2017). Dieback of large baobab trees was recently reported from southern Africa: various microorganisms were described to be associated with symptoms, but the causes are still uncertain (Cruywagen, Crous, Roux, Slippers, & Wingfield, 2015;Cruywagen, Slippers, Roux, & Wingfield, 2017). ...
Societal Impact Statement
The increasing occurrence of native and non‐native pests and diseases of trees in Africa is impacting rural livelihoods, economic development, and biodiversity across the continent. Here we provide an updated and comprehensive overview of insect pests and pathogens targeting natural and planted forests in Africa, and raise awareness of this growing emergency. Data availability and limited biosecurity of some countries are limiting the ability to tackle this invasion. An improved knowledge of taxonomy, distribution, and damage caused by these organisms will be crucial for developing continent‐wide strategies to manage this emergency and enhance country‐level intervention capacity.
Summary
An increasing multitude of insect pests and pathogens is targeting indigenous trees of natural forests, agroforestry systems, and exotic trees in planted forests in Africa. This is raising major concerns for a continent already challenged by adaptations to climate change, as it threatens a vital resource for food security of rural communities, economic growth, and ecosystem conservation. The accidental introduction through trade of non‐native species in particular is accelerating, and it adds to the damage to tree‐based landscapes by native pests and diseases. Old‐time and new invaders heavily impact planted forests of exotic eucalypts, pines, and acacias, and are spreading quickly across African regions. But many non‐native pathogens are recently found affecting important indigenous trees. We describe the threat to African trees by providing an overview of highly relevant insect pests and diseases of indigenous and exotic trees in Africa, and discuss implications for management and future research. The implementation of an integrated and globally coordinated approach based on improved biosecurity, biological control, and tree resistance would contribute to mitigate the potentially devastating impact of these invasions on African natural resources.
... We identified homologues of these genes across a range of pathogens capable of infecting woody plants and previously sequenced Botryosphaeriaceae species. The majority of Botryosphaeriaceae species are reported as pathogens or endophytes (and opportunistic pathogens) of woody plants (Slippers and Wingfield 2007), including other Eutiarosporella spp. that have been isolated from woody plants (Jami et al. 2012(Jami et al. , 2014. Among this family, SMs have long been considered important during infection of woody plants, with multiple phytotoxic compounds identified in culture (Fischer and Thines 2017). ...
... Woody plants might be acting as additional reservoirs for these pathogens, including E. tritici-australis, which might still grow as an endophyte in woody plants. This would be similar to other Eutiarosporella spp. that were isolated from nondiseased woody plant tissue (Jami et al. 2012). If this is the case, then perhaps disease inoculum for WGD may arise from woody plant reservoirs. ...
White grain disorder is a recently emerged wheat disease in Australia, caused by Eutiarosporella darliae, E. pseudodarliae, and E. tritici-australis. The disease cycle of these pathogens and the molecular basis of their interaction with wheat are poorly understood. To address this knowledge gap, we undertook a comparative genomics analysis focused on the secondary metabolite gene repertoire among these three species. This analysis revealed a diverse array of secondary metabolite gene clusters in these pathogens, including modular polyketide synthase genes. These genes have only been previously associated with bacteria and this is the first report of such genes in fungi. Subsequent phylogenetic analyses provided strong evidence that the modular PKS genes were horizontally acquired from a bacterial or a protist species. We also uncovered a secondary metabolite gene cluster with three polyketide/non-ribosomal peptide synthase genes (Hybrid-1, -2, and -3) in E. darliae and E. pseudodarliae. In contrast, only remnant and partial genes homologous to this cluster were identified in E. tritici-australis, suggesting loss of this cluster. Homologues of Hybrid-2 in other fungi have been proposed to facilitate disease in woody plants, suggesting a possible alternative host range for E. darliae and E. pseudodarliae. Subsequent assays confirmed that E. darliae and E. pseudodarliae were both pathogenic on woody plants, but E. tritici-australis was not, implicating woody plants as potential host reservoirs for the fungi. Combined, these data have advanced our understanding of the lifestyle and potential host-range of these recently emerged wheat pathogens and shed new light on fungal secondary metabolism.
... To clarify the position of species related to unidentifed Neofusicoccum, we also included sequence data from the β-tubulin (TUB2) gene amplified with primers BT2a and BT2b (Glass and Donaldson 1995) for a selected group of isolates. The conditions for the PCRs were the same as those described in Jami et al. (2012). ...
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.
... Thus, the 30 or more species of Diplodia currently known from culture Dissanayake et al., 2016;Gonz alez-Domínguez et al., 2017;Yang et al., 2017) have been delimited on the basis of the Genealogical Concordance Phylogenetic Species Recognition (GCPSR) proposed by Taylor et al. (2000). This has been based largely on sequence data of two loci, the ribosomal internal transcribed spacer (ITS rDNA) and the translation elongation factor 1-alpha (tef1-a) (Lazzizera et al., 2008;Jami et al., 2012;Phillips et al. 2012Phillips et al. , 2013Linaldeddu et al., 2013;Lynch et al., 2013;Alves et al., 2014). ...
Cryptic species are common in Diplodia, a genus that includes some well-known and economically important plant pathogens. Thus, species delimitation has been based on the phylogenetic species recognition approach using multigene genealogies. We assessed the potential of mating type (MAT) genes sequences as phylogenetic markers for species delimitation in the genus Diplodia. A PCR-based mating type diagnostic assay was developed that allowed amplification and sequencing of the MAT1-1-1 and MAT1-2-1 genes, and determination of the mating strategies used by different species. All species tested were shown to be heterothallic. Phylogenetic analyses were performed on both MAT genes and also, for comparative purposes, on concatenated sequences of the ribosomal internal transcribed spacer (ITS), translation elongation factor 1-alpha (tef1-α) and beta-tubulin (tub2). Individual phylogenies based on MAT genes clearly differentiated all species analysed and agree with the results obtained with the commonly used multilocus phylogenetic analysis approach. However, MAT genes genealogies were superior to multigene genealogies in resolving closely related cryptic species. The phylogenetic informativeness of each locus was evaluated revealing that MAT genes were the most informative loci followed by tef1-α. Hence, MAT genes can be successfully used to establish species boundaries in the genus Diplodia.
... Botryosphaeriales associated with native trees A number of relatively intensive studies have been completed on Botryosphaeriales on native trees in South Africa and Namibia. In total, 52 Botryosphaeriales species have been characterised from both symptomatic and asymptomatic tissues on 32 native tree species studied in these two countries (Marincowitz et al. 2008;Denman et al. 2003;Begoude et al. 2010;Mehl et al. 2011;Van der Linde et al. 2011;Ndove 2015;Jami et al. 2012Jami et al. , 2013Jami et al. , 2014Jami et al. , 2015Swart 1986;Osorio et al. 2017;Mehl et al. 2017a;Cruywagen et al. 2017). Of these, 18 species were isolated from Vachellia (Acacia) species (Jami et al. 2012(Jami et al. , 2013(Jami et al. , 2015Slippers et al. 2014), 14 species were from mangrove trees (Osorio et al. 2017), 12 species from Syzygium cordatum (Pavlic et al. 2007), 12 species from Sclerocarya birrea subsp. ...
... In total, 52 Botryosphaeriales species have been characterised from both symptomatic and asymptomatic tissues on 32 native tree species studied in these two countries (Marincowitz et al. 2008;Denman et al. 2003;Begoude et al. 2010;Mehl et al. 2011;Van der Linde et al. 2011;Ndove 2015;Jami et al. 2012Jami et al. , 2013Jami et al. , 2014Jami et al. , 2015Swart 1986;Osorio et al. 2017;Mehl et al. 2017a;Cruywagen et al. 2017). Of these, 18 species were isolated from Vachellia (Acacia) species (Jami et al. 2012(Jami et al. , 2013(Jami et al. , 2015Slippers et al. 2014), 14 species were from mangrove trees (Osorio et al. 2017), 12 species from Syzygium cordatum (Pavlic et al. 2007), 12 species from Sclerocarya birrea subsp. caffra (Mehl et al. 2017a), 11 species from A. mellifera , and nine species from Adansonia digitata s.l (Cruywagen et al. 2017) and Podocarpus spp. ...
... Of the 62 Botryosphaeriales species isolated from 66 hosts during the course of the last decade in South Africa and Namibia (Table 1; Fig. 1), 12 have been described as new taxa from non-native hosts and 27 as new from native hosts (Table 1) Pavlic et al. 2004;Denman et al. 2003;Jami et al. 2012Jami et al. , 2014Jami et al. , 2015Mehl et al. 2014;Osorio et al. 2017). Eleven of the Botryosphaeriales species have been isolated from both native and non-native trees in the region, and these represent species with an almost cosmopolitan distribution and very broad host ranges (Fig. 1, Table 1). ...
The Botryosphaeriales includes serious plant pathogens with a broad host and geographic distribution globally. In South Africa and Namibia, these fungi include important pathogens of native and non-native woody plants, and have consequently been studied extensively. Here we synthesize the information from the previous studies, particularly in the last decade, that report 62 species in the Botryosphaeriales from 66 hosts across South Africa and Namibia. Of these, 52 species have been reported from native hosts, 17 are from non-native hosts and twelve of these species occur on both native and non-native trees in the region. Much of the diversity of the Botryosphaeriales can be ascribed to native species that have fairly limited host and geographic ranges. Neofusicoccum parvum is amongst the most common species on both native and non-native hosts and it is thought to be native to the region. In contrast, Botryosphaeria dothidea, which is certainly an introduced species, is also widespread, and is very common on both native and non-native plants. Overall this synthesis underscores the growing understanding of the diversity of an important group of tree pathogens, their apparently common global spread as latent agents of disease, as well as their apparently common movement between commercial and native ecosystems.
