10 research outputs found
Future danger posed by fungi in the Ophiostomatales when encountering new hosts
The Ophiostomatales contain pathogens that threaten forests world-wide. Global trade
increases encounters with new hosts, with potential devastating consequences. We assessed
the danger posed by the movement of Ophiostomatales between different host trees in South
Africa. We tested the pathogenicity of five fungal species from native South African trees,
and three from exotic trees, on various native and exotic trees. To evaluate the potential of
fungi to move to new hosts, we investigated the strength of their associations with arthropod
vectors. Results indicate that many fungal species are pathogens of newly encountered and
distantly-related hosts. Encounters of pathogens with new hosts are less likely when host
plants are distantly related, and outside the host range of boring beetle vectors, which also reduces the chances of vectoring by phoretic mite associates. However, pathogens associated
with numerous mite species and wounds are more likely to encounter new hosts and pose
future threats.The authors thank the DST/NRF Centre of Excellence in Tree
Health Biotechnology (CHTB) for financial support and the South
African National Parks Board (SANPARKS) and Western Cape Nature
Conservation Board for issuing the necessary collecting permits.http://www.journals.elsevier.com/fungal-ecology2017-08-31hb2016Microbiology and Plant Patholog
Wounds on Rapanea melanophloeos provide habitat for a large diversity of Ophiostomatales including four new species
Rapanea melanophloeos, an important canopy tree in Afromontane forests,
is commonly utilised for medicinal bark harvesting. Wounds created from these
activities provide entrance for many fungi, including arthropod-associated members
of the Ophiostomatales and Microascales (ophiostomatoid fungi). In this study we
assess the diversity of wound-associated Ophiostomatales on storm-damaged R.
melanophloeos trees in the Afromontane forests of South Africa. Five species were identified based on micro-morphological and molecular phylogenetic analyses. These
included Ophiostoma stenoceras and four newly described taxa Sporothrix itsvoense
sp. nov., S. rapaneae sp. nov., S. utae sp. nov. and O. noisomeae sp. nov. Four of
these are members of the S. schenckii-O. stenoceras complex (O. stenoceras, S.
itsvoense sp. nov., S. rapaneae sp. nov., S. utae) while O. noisomeae groups basal in
the Ophiostomatales alongside the S. lignivora complex and Graphilbum. In addition
to other taxa known from this host, the present study shows that there is a rich, yet
still poorly explored, diversity of Ophiostomatales associated with R. melanophloeos
in Afromontane forests. More taxa are likely to be discovered with increased research
effort. These must be assessed in terms of pathogenicity towards this ecologically and
economically important tree.http://link.springer.com/journal/104822017-06-30hb2016GeneticsMicrobiology and Plant Patholog
New species of Ophiostomatales from Scolytinae and Platypodinae beetles in the Cape Floristic Region, including the discovery of the sexual state of Raffaelea
Olea capensis and Rapanea melanophloeos
are important canopy trees in South African
Afromontane forests. Dying or recently dead individuals
of these trees are often infested by Scolytinae and
Platypodinae (Curculionidae) beetles. Fungi were
isolated from the surfaces of beetles emerging from
wood samples and their galleries. Based on micromorphological
and phylogenetic analyses, four fungal
species in the Ophiostomatales were isolated. These were Sporothrix pallida and three taxa here newly
described as Sporothrix aemulophila sp. nov., Raffaelea
vaginata sp. nov. and Raffaelea rapaneae sp. nov.
This study represents the first collection of S. pallida, a
species known from many environmental samples
from across the world, from Scolytinae beetles. S.
aemulophila sp. nov. is an associate of the ambrosia
beetle Xyleborinus aemulus. R. rapaneae sp. nov. and
R. vaginata sp. nov. were associated with a Lanurgus
sp. and Platypodinae beetle, respectively, and represent
the first Raffaelea spp. reported from the Cape
Floristic Region. Of significance is that R. vaginata
produced a sexual state analogous with those of Ophiostoma seticolle and O. deltoideosporum that
also grouped in our analyses in Raffaelea s. str., to date
considered an asexual genus. The morphology of the
ossiform ascospores and anamorphs of the three
species corresponded and the generic circumscription
of Raffaelea is thus emended to accommodate sexual
states. The two known species are provided with new
combinations, namely Raffaelea seticollis (R.W.
Davidson) Z.W. de Beer and T.A. Duong comb. nov.
and Raffaelea deltoideospora (Olchow. and J. Reid)
Z.W. de Beer and T.A. Duong comb. nov.DST/NRF Centre of Excellence in Tree Health Biotechnology (CHTB).http://link.springer.com/journal/104822016-10-30hb201
Insects, Rodents, and Pets as Reservoirs, Vectors, and Sentinels of Antimicrobial Resistance
This paper reviews the occurrence of antimicrobial resistance (AMR) in insects, rodents, and pets. Insects (e.g., houseflies, cockroaches), rodents (rats, mice), and pets (dogs, cats) act as reservoirs of AMR for first-line and last-resort antimicrobial agents. AMR proliferates in insects, rodents, and pets, and their skin and gut systems. Subsequently, insects, rodents, and pets act as vectors that disseminate AMR to humans via direct contact, human food contamination, and horizontal gene transfer. Thus, insects, rodents, and pets might act as sentinels or bioindicators of AMR. Human health risks are discussed, including those unique to low-income countries. Current evidence on human health risks is largely inferential and based on qualitative data, but comprehensive statistics based on quantitative microbial risk assessment (QMRA) are still lacking. Hence, tracing human health risks of AMR to insects, rodents, and pets, remains a challenge. To safeguard human health, mitigation measures are proposed, based on the one-health approach. Future research should include human health risk analysis using QMRA, and the application of in-silico techniques, genomics, network analysis, and ’big data’ analytical tools to understand the role of household insects, rodents, and pets in the persistence, circulation, and health risks of AMR
Biodiversity and ecology of ophiostomatoid fungi associated with trees in the Cape floristic region of South Africa
Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Very little is known about the diversity of fungi associated with Afromontane forests of the Cape Floristic Region (CFR) of South Africa. The ophiostomatoid fungi include many species, some known as pathogens in the CFR, while others are well-known saprophytes important in wood degradation. This study focused on the biodiversity and ecology of tree-associated ophiostomatoid fungi (Ophiostomatales) in the CFR. In addition to this, mites and subcortical beetles associated with the CFR trees were collected, regardless of whether they were associated with ophiostomatoid fungi or not. A relatively high diversity of ophiostomatoid fungi were collected from native trees, ten of which were newly described here. Three further fungal species, two of which are probably new to science, were also collected from exotic Pinus species growing in these forests. Four Ophiostomatales species (including three newly described species) were associated with subcortical beetles on Rapanea melanophloeos and Olea capensis ssp. macrocarpa. These were Sporothrix pallida, Sporothrix aemuluphilus, Raffaelea scabbardiae and Raffaelea rapaneae, associated with the beetles Lanurgus sp. 1, Ctonoxylon sp. 1, Xyleborinus aemuluphilus and a Platypodinae species. This represents a first study to explore the associations between subcortical beetles and ophiostomatoid fungi on native trees in the CFR. In addition to fungi associated with subcortical beetles, several members of the Ophiostomatales associated with wounds on Rapanea melanophloes trees were also collected. These included Ophiostoma stenoceras, Sporothrix reniformis, S. rapaneae, S. lunateae and S. noisomeae. All but O. stenoceras were new to science, and were formally described here. All of these wound-associated species from R. melanophloeos belong to the Sporothrix schenckii – O. stenoceras complex, except for S. noisomeae that was provisionally placed in the S. lignivora complex. Besides fungal taxa collected from wounds on Rapanea melanophloeos, other fungi were also collected from wounds on other host trees species. Three more previously undescribed ophiostomatoid fungal species were collected from this niche. They included Sporothix capensis collected from O. capensis ssp. macrocarpa, Graphilbum roseus collected from many different, unrelated host trees and Graphium ilexiense (Microascales), isolated from wounds on Ilex mitis. The latter represented the first isolation of an ophiostomatoid fungus from this host tree species. Two possibly new fungal species (Sporothrix sp. 1, Ceratocystiopsis sp. 1) and Ophiostoma ips, associated with three bark beetles (Orthotomicus erosus, Hylurgus ligniperda and Hylastes angustatus), were collected from Pinus. Several fungal species were collected from both native trees and non-native trees. These included Sporothrix fusiforme from Brabejum stellatifolium and Acacia mearnsii, O. quercus and O. pluriannulatum-like fungus from several native trees and from A. mearnsii. This suggests a possibility for host shifting of some of these fungi between native and non-native hosts or even between different native hosts. Eight non-ophiostomatoid fungi associated subcortical beetles taxa were found also to infest native trees in the Afromontane forests and in total more than 4500 beetle individuals were collected. Some species of ophiostomatoid fungi collected in this study were found to be associated with other arthropods such as mites. Four phoretic mites species associated with ophiostomatoid fungi (Dendrolaelaps quadrisetus, Histiogaster sp. 3, Elattoma sp. 1 & 2) were collected. In addition, sixteen species of tree wound-associated mites were collected from 12 native trees. Of these, nine were associated with several ophiostomatoid fungi (Graphilbum roseus, O. pluriannulatum-like, O. quercus) that were isolated from several different host trees. This suggests that they may aid in the transport of these fungi from one host species to another.
The possible consequences of transfers of Ophiostomatales species between hosts were tested using pathogenicity tests, which highlighted that some fungi are pathogenic on several different trees. Transfers seemed most likely in fungal species isolated from wounds, especially those associated with mites, because the mites may aid in the vectoring of these. When phoretic mites were tested for their specificity to their vector beetles, they proved to be highly specific. Although some of the fungi associated with these mites and their sub-cortical beetles were also pathogenic, it is less likely for these fungi to be transferred to other host tree species due to the high specificity of their arthropod associates. This study represents one of a few studies that focused on ophiostomatoid fungi, subcortical beetles and mites associated with trees in the Afromontane forests of South Africa. Although we collected a high diversity of Ophiostomatales members, many more still await discovery. It is recommended that future studies focus on the complex inter-organismal interactions in many of the systems uncovered in this study.AFRIKAANSE OPSOMMING: Baie min is bekend oor die diversiteit van fungi wat met die Afromontane woude van die Kaapse Floristiese Streek (KFS) van Suid Afrika geassosieer is. Die ophiostomatoïde fungi sluit baie spesies in, sommiges bekend as patogene in die KFS, terwyl ander bekende en belangrike saprofiete in houtdegradasie is. Hierdie studie het op die biodiversiteit en ekologie van die boom-geassosieerde ophiostomatoïde fungi (Ophiostomatales) in die KFS gefokus. Daarbenewens is myte en subkortikale kewers wat met die KFS bome geassosieer word ook versamel, ongeag of hulle geassosieerd was met ophiostomatoïde fungi of nie. „n Relatief hoë diversiteit van ophiostomatoïde fungi is van inheemse bome versamel, tien waarvan hier nuut beskryf is. Drie verdere fungi spesies, twee waarvan ook waarskynlik nuut is tot die wetenskap, is ook vanaf Pinus spesies versamel wat in hierdie woude gegroei het. Vier Ophiostomatales spesies (insluitend drie nuut beskryfde spesies) wat met subkortikale kewers op Rapanea melanophloeos en Olea capensis L. ssp. macrocarpa geassosieer is, is ook versamel. Hulle was Sporothrix pallida, Sporothrix aemuluphilus, Raffaelea scabbardiae en Raffaelea rapaneae, geassosieer met die kewers Lanurgus sp. 1, Ctonoxylon sp. 1, Xyleborinus aemuluphilus en „n Platypodinae spesie. Hierdie verteenwoordig die eerste studie wat die assosiasies tussen subkortikale kewers en ophiostomatoïde fungi op inheemse bome in die KFS ondersoek. Addisioneel tot fungi geassosieer met die subkortikale kewers, is verskeie lede van die Ophiostomatales vanaf wonde op Rapanea melanophloes bome versamel. Hulle sluit in Ophiostoma stenoceras, Sporothrix reniformis, S. rapaneae, S. lunateae en S. noisomeae. Almal behalwe O. stenoceras was nuut tot die wetenskap, en is hier formeel beskryf. Al hierdie wond-geassosieerde spesies vanaf R. melanophloeos behoort aan die Sporothrix schenckii – O. stenoceras kompleks, behalwe vir S. noisomeae wat voorlopig in die S. lignivora kompleks geplaas is. Benewens fungi taxa wat van die wonde op Rapanea melanophloes versamel is, is ander fungi ook vanaf die wonde op ander gasheer boom spesies versamel. Drie verdere ophiostomatoïde fungus spesies is in hierdie nis versamel. Hulle sluit in Sporothix capensis wat vanaf O. capensis ssp. macrocarpa versamel is, Graphilbum roseus wat vanaf baie verskillende, onverwante gasheer bome versamel is en Graphium ilexiense (Microascales), wat vanaf wonde op Ilex mitis versamel is. Laasgenoemde verteenwoordig die eerste isolasie van „n ophiostomatoïde fungus vanaf hierdie gasheer boom spesie. Twee moontlik nuwe fungus spesies (Sporothrix sp. 1, Ceratocystiopsis sp. 1) en Ophiostoma ips, geassosieer met drie baskewers (Orthotomicus erosus, Hylurgus ligniperda en Hylastes angustatus) is vanaf Pinus versamel. Verskeie fungi spesies is van beide inheemse en nie-inheemse bome versamel. Hulle het Sporothrix fusiforme vanaf Brabejum stellatifolium en Acacia mearnsii, O. quercus en O. pluriannulatum-like fungus vanaf verskeie inheemse bome en vanaf A. mearnsii ingesluit. Dit suggereer die moontlikheid van gasheer-skuiwing van sommige van hierdie fungi tussen inheemse en uitheemse gashere of selfs tussen verskillende inheemse gashere. Agt nie- ophiostomatoïde geassosieerde subkortikale kewers was ook versamel en in totaal is meer as 4500 kewer indiwidue versamel. Sommige ophiostomatoïde fungus spesies wat in hierdie studie versamel is, was met ander geleedpotiges soos myte geassosieer. Vier foretiese myt spesies wat met ophiostomatoïde fungi geassosieer is (Dendrolaelaps quadrisetus, Histiogaster sp. 3, Elattoma sp. 1 & 2), is versamel. Nege addisioneële myt spesies was met verskeie ophiostomatoïde spesies vanaf verskeie boomspesies geassosieer (Graphilbum roseus, O. pluriannulatum-like, O. quercus). Dit suggereer dat myte die vervoer van hierdie fungi van een gasheer spesie na die ander mag bewerkstellig.
Die moontlike gevolge van die oordrag van Ophiostomatales spesies tussen gashere is getoets deur patogeniteitstoetse. Dit het beklemtoon dat sommige fungi patogenies is op verskeie onverwante boomspesies. Oordraag van spesies is mees waarskynlik in fungi spesies wat vanaf wonde geisoleer is, veral dié wat met myte geassosieer is, want die myte mag hierdie fungi help vervoer. Toe foretiese myte getoets is vir hulle spesifisiteit tot hulle vektore, is hulle hoogs spesifiek bevind. Alhoewel sommige fungi wat met hierdie myte en hulle geassosieerde kewers geassosieer word wel patogenies is, is dit minder waarskylik dat hulle na ander gasheer bome sal verskuif as gevolg van die hoë spesifisiteit van hulle geleedpotige assosiate. Hierdie studie verteenwoordig een van net enkele studies gefokus op ophiostomatoïde fungi, subkortikale kewers en myte wat met bome van die Afromontane woude van Suid-Afrika geassosieer is. Alhoewel ons „n hoë diversiteit van Ophiotomatale lede versamel het, wag baie meer fungi spesies waarskynlik nog op ontdekking. Daar word voorgestel dat toekomstige studies fokus op die komplekse inter-organismiese interaksies in baie van die sisteme wat in hierdie studie blootgelê is
Big Data in Biodiversity Science: A Framework for Engagement
Despite best efforts, the loss of biodiversity has continued at a pace that constitutes a major threat to the efficient functioning of ecosystems. Curbing the loss of biodiversity and assessing its local and global trends requires a vast amount of datasets from a variety of sources. Although the means for generating, aggregating and analyzing big datasets to inform policies are now within the reach of the scientific community, the data-driven nature of a complex multidisciplinary field such as biodiversity science necessitates an overarching framework for engagement. In this review, we propose such a schematic based on the life cycle of data to interrogate the science. The framework considers data generation and collection, storage and curation, access and analysis and, finally, communication as distinct yet interdependent themes for engaging biodiversity science for the purpose of making evidenced-based decisions. We summarize historical developments in each theme, including the challenges and prospects, and offer some recommendations based on best practices
New ophiostomatoid fungi from wounds on storm-damaged trees in Afromontane forests of the Cape Floristic Region
Ophiostomatoid fungi, a well-known tree-associated group, include some of the most important forest pathogens globally. Several ophiostomatoid species were reported already from Rapanea melanophloeos of the Afromontane forests from the Cape Floristic Region (CFR) of South Africa. The aim of this study was to investigate the diversity of ophiostomatoid fungi associated with wounds on other Afromontane forest tree species in the CFR. Storm-damaged trees were surveyed and fungi were isolated from bark and wood samples. Two undescribed ophiostomatoid species were identified based on micro-morphological characters and phylogenetic analyses. They are newly described here as Graphilbum roseum and Sporothrix oleae. A third taxon in the genus Graphium may also represent an undescribed species, but additional data is required to support this hypothesis. Sporothrix oleae, a species that groups within the S. candida species complex, was associated with Olea capensis. Graphilbum roseum was isolated from several host tree species including Curtisia dentata, Halleria lucida and Pterocelastrus tricuspidatus, while the Graphium sp. was isolated from Ilex mitis.ELECTRONIC SUPPLEMENTARY MATERIAL :
SUPPLEMENTARY FIGURE 1. Bayesian Inference consensus tree based on ITS sequence data for species of Sporothrix. Values above nodes indicate posterior probabilities obtained through Bayesian Inference. Values below nodes indicate bootstrap values (1000 replicates) obtained from Maximum Likelihood analysis. The scale bar is in substitutions per site.SUPPLEMENTARY FIGURE 2. Bayesian Inference consensus tree based on ITS sequence data for species of Graphium. Values above nodes indicate posterior probabilities obtained through Bayesian Inference. Values below nodes indicate bootstrap values (1000 replicates) obtained from Maximum Likelihood analysis. The scale bar is in substitutions per site.SUPPLEMENTARY TABLE 1. Ophiostomatoid strains and GenBank accession numbers of ITS sequences used for the phylogenetic analysis (Sprorothrix ITS data set)SUPPLEMENTARY TABLE 2. Ophiostomatoid strains and GenBank accession numbers of ITS sequences used for the phylogenetic analysis (Graphium ITS data set)The Department of Science and Innovation (DSI)/National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology (CTHB).http://link.springer.com/journal/11557hj2021BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyPlant Production and Soil Scienc
Editorial: Invasive pathogens and arthropods: biogeography, drivers of invasion success, impacts on indigenous forest trees and emerging management strategies
Bark beetle mycobiome : collaboratively defined research priorities on a widespread insect-fungus symbiosis
CITATION: Hulcr, J. et al. 2020. Bark beetle mycobiome : collaboratively defined research priorities on a widespread insect-fungus symbiosis. Symbiosis, 81:101–113, doi:10.1007/s13199-020-00686-9.The original publication is available at https://www.springer.com/journal/13199One of the main threats to forests in the Anthropocene are novel or altered interactions among trees, insects and fungi. To critically assess the contemporary research on bark beetles, their associated fungi, and their relationships with trees, the international Bark Beetle Mycobiome research coordination network has been formed. The network comprises 22 researchers from 17 institutions. This forward-looking review summarizes the group’s assessment of the current status of the bark beetle mycobiome research field and priorities for its advancement. Priorities include data mobility and standards, the adoption of new technologies for the study of these symbioses, reconciliation of conflicting paradigms, and practices for robust inference of symbiosis and tree epidemiology. The Net work proposes contemporary communication strategies to interact with the global community of researchers studying symbioses and natural resource managers. We conclude with a call to the broader scientific community to participate in the network and contribute their perspectives.Publisher's versio