Grapevine trunk diseases have become one of the main threats to grape production worldwide, with Diaporthe species as an emerging group of pathogens in China. At present, relatively little is known ...about the taxonomy and genetic diversity of Chinese Diaporthe populations, including their relationships to other populations worldwide. Here, we conducted an extensive field survey in six provinces in China to identify and characterize Diaporthe species in grape vineyards. Ninety-four isolates were identified and analyzed using multi-locus phylogeny. The isolates belonged to eight species, including three novel taxa, Diaporthe guangxiensis (D. guangxiensis), Diaporthe hubeiensis (D. hubeiensis), Diaporthe viniferae (D. viniferae), and three new host records, Diaporthe gulyae (D. gulyae), Diaporthe pescicola (D. pescicola), and Diaporthe unshiuensis (D. unshiuensis). The most commonly isolated species was Diaporthe eres (D. eres). In addition, high genetic diversity was observed for D. eres in Chinese vineyards. Haplotype network analysis of D. eres isolates from China and Europe showed a close relationship between samples from the two geographical locations and evidence for recombination. In comparative pathogenicity testing, D. gulyae was the most aggressive taxon, whereas D. hubeiensis was the least aggressive. This study provides new insights into the Diaporthe species associated with grapevines in China, and our results can be used to develop effective disease management strategies.Grapevine trunk diseases have become one of the main threats to grape production worldwide, with Diaporthe species as an emerging group of pathogens in China. At present, relatively little is known about the taxonomy and genetic diversity of Chinese Diaporthe populations, including their relationships to other populations worldwide. Here, we conducted an extensive field survey in six provinces in China to identify and characterize Diaporthe species in grape vineyards. Ninety-four isolates were identified and analyzed using multi-locus phylogeny. The isolates belonged to eight species, including three novel taxa, Diaporthe guangxiensis (D. guangxiensis), Diaporthe hubeiensis (D. hubeiensis), Diaporthe viniferae (D. viniferae), and three new host records, Diaporthe gulyae (D. gulyae), Diaporthe pescicola (D. pescicola), and Diaporthe unshiuensis (D. unshiuensis). The most commonly isolated species was Diaporthe eres (D. eres). In addition, high genetic diversity was observed for D. eres in Chinese vineyards. Haplotype network analysis of D. eres isolates from China and Europe showed a close relationship between samples from the two geographical locations and evidence for recombination. In comparative pathogenicity testing, D. gulyae was the most aggressive taxon, whereas D. hubeiensis was the least aggressive. This study provides new insights into the Diaporthe species associated with grapevines in China, and our results can be used to develop effective disease management strategies.
This is the opening paper in the special issue of
Fungal Diversity,
which collates the data on defining species. Defining and recognizing species has long been a controversial issue. Since Darwin's ...proposed origin of species, over 30 species criteria have been brought forth and used to define species boundaries. In recent times, phylogenetic analyses based on multiple loci have been extensively used as a method to define species boundaries. However, only a few mycologists are aware that phylogenetic species criteria can mask discordances among fungal groups, leading to inaccurately defined species boundaries. In the current review, we discuss species recognition criteria, how and where these criteria can be applied along with their limitations and derived alternatives. In order to delimit fungal species, authors need to take into account not only the phylogenetic and phenotypic coherence, but also the timing of events that lead to fungal speciation and subsequent diversifications. Variations in the rate of phenotypic diversifications and convergent fungal evolution make it difficult to establish a universal species recognition criterion. The best practice can only be defined in the context of each fungal group. In this review, we provide a set of guidelines, encouraging an integrative taxonomic approach for species delimitation that can be used to define fungal species boundaries in the future. The other papers in this special issue deal with fungal speciation in
Ascomycota, Dothideomycetes
,
Basidiomycota
, basal fungi, lichen-forming fungi, plant pathogenic fungi, and yeasts.
species are associated with
as endophytes, pathogens, and saprobes worldwide. However, little is known about
as endophytes in
in China. In this study, 24 endophytic
isolates were obtained from ...cultivated
cv. "Tomentosa" in Huazhou, Guangdong Province in 2019. The nuclear ribosomal internal transcribed spacer (ITS), partial sequences of translation elongation factor 1-α (
), β-tubulin (
), and partial calmodulin (
) gene regions were sequenced and employed to construct phylogenetic trees. Based on morphology and combined multigene phylogeny, eleven
species were identified including two new species,
and
. These are the first report of
,
,
,
,
,
,
, and
on
. This study provides the first intensive study of endophytic
species on
cv. tomentosa in China. These results will improve the current knowledge of
species associated with
. The results obtained in this study will also help to understand the potential pathogens and biocontrol agents and to develop a platform in disease management.
Leaf spot is a common and serious disease of sweet cherry worldwide and has become a major concern in China. From 2018 to 2020, disease investigations were carried out in Beijing City, Sichuan, ...Shandong, and Liaoning Provinces in China, and 105
isolates were obtained from diseased samples. Isolates were identified by morphological characterization coupled with multigene phylogenetic analyses based on six loci (internal transcribed spacer region, glyceraldehyde 3-phosphate dehydrogenase, calmodulin, actin, chitin synthase, and β-tubulin). A total of 13
species were identified, namely
,
,
,
,
,
,
,
,
,
,
,
, and
Among these,
(25.7%) was the most prominent species isolated from diseased leaves, followed by
(19.0%) and
(12.4%). Pathogenicity was tested on detached leaves of cv. 'Tieton' and 'Summit' and young seedlings of cv. 'Brooks' under greenhouse conditions. All 13 species were pathogenic to cherry leaves, and
,
, and
showed high levels of virulence. Seedlings inoculated with the isolates developed similar symptoms to those seen in the orchards. This study provides the first reports for 11 of the 13
species on sweet cherry in the world, excluding
and
. This is the first comprehensive study of
species associated with cherry leaf spot in China, and the results will provide basic knowledge to develop sustainable control measures for cherry leaf spot.
Aglaonema modestum
(
A. modestum
) (Araceae) is an evergreen herbage, which is intensively grown as an ornamental plant in South China. A new disease was observed in
A. modestum
from 2020 to 2021 in ...Guangdong province, China. The disease symptoms associated with plants were initial leaf wilt, stem rot, and resulting plant death, leading to severe economic losses. In total, six
Fusarium
isolates were obtained from diseased plants. The putative pathogen was identified using both morphological characteristics and molecular phylogenetic analysis of calmodulin A (
cmdA
), RNA polymerase largest subunit 1 (
rpb1
), RNA polymerase II (
rpb2
), translation elongation factor-1α (
tef1-
α), and beta-tubulin (β
-tubulin
) sequences. Two
Fusarium
species were identified, namely, one new species,
Fusarium aglaonematis
(
F. aglaonematis
) belonging to
Fusarium fujikuroi
species complex. In addition,
Fusarium elaeidis
(
F. elaeidis
) belonging to the
Fusarium oxysporum
(
F. oxysporum
) species complex was also identified. Pathogenicity assays were conducted by inoculating each species into potted
A. modestum
plants and co-inoculating two species. The results showed that two
Fusarium
species could infect plants independently and can infect them together. Co-infection of these two species enhanced the disease severity of
A. modestum
. Compared to single inoculation of
F. elaeidis
, severity was higher and disease development was quicker when plants were only inoculated with
F. aglaonematis
. In addition, these two
Fusarium
species could infect
Aglaonema
plants without wounds, while inoculation with a physical injury increased disease severity. This is the first report of co-infection by
F. aglaonematis
and
F. elaeidis
causing stem rot on
A. modestum
worldwide. This study will be an addition to the knowledge of
Fusarium
diseases in ornamental plants. These results will provide a baseline to identify and control diseases associated with
A. modestum.
What is a species in fungal plant pathogens? Jayawardena, Ruvishika S.; Hyde, Kevin D.; de Farias, Antonio Roberto Gomes ...
Fungal diversity,
07/2021, Letnik:
109, Številka:
1
Journal Article
Recenzirano
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.
The global diversity of fungi has been estimated using several different approaches. There is somewhere between 2–11 million estimated species, but the number of formally described taxa is around ...150,000, a tiny fraction of the total. In this paper, we examine 12 ascomycete genera as case studies to establish trends in fungal species descriptions, and introduce new species in each genus. To highlight the importance of traditional morpho-molecular methods in publishing new species, we introduce novel taxa in 12 genera that are considered to have low species discovery. We discuss whether the species are likely to be rare or due to a lack of extensive sampling and classification. The genera are
Apiospora
,
Bambusicola
,
Beltrania
,
Capronia
,
Distoseptispora
,
Endocalyx
,
Neocatenulostroma
,
Neodeightonia
,
Paraconiothyrium
,
Peroneutypa
,
Phaeoacremonium
and
Vanakripa
. We discuss host-specificity in selected genera and compare the number of species epithets in each genus with the number of ITS (barcode) sequences deposited in GenBank and UNITE. We furthermore discuss the relationship between the divergence times of these genera with those of their hosts. We hypothesize whether there might be more species in these genera and discuss hosts and habitats that should be investigated for novel species discovery.
In plant pathology, the correct naming of a species is essential for determining the causal agents of disease. Species names not only serve the general purpose of concise communication, but also are ...critical for effective plant quarantine, preventing the introduction of new pathogens into a territory. Many phytopathogenic genera have multiple species and, in several genera, disagreements between the multiple prevailing species concept definitions result in numerous cryptic species. Some of these species were previously called by various names;
forma speciales
(specialised forms), subspecies, or pathotypes. However, based on new molecular evidence they are being assigned into new species. The frequent name changes and lack of consistent criteria to delineate cryptic species, species, subspecies, forms, and races create increasing confusion, often making communication among biologists arduous. Furthermore, such ambiguous information can convey misleading evolutionary concepts and species boundaries. The aim of this paper is to review these concepts, clarify their use, and evaluate them by referring to existing examples. We specifically address the question, “Do plant pathogens require a different ranking system?” We conclude that it is necessary to identify phytopathogens to species level based on data from multiple approaches. Furthermore, this identification must go beyond species level to clearly classify hitherto known subspecies, forms and races. In addition, when naming phytopathogenic genera, plant pathologists should provide more information about geographic locations and host ranges as well as host specificities for individual species, cryptic species, forms or races. When describing a new phytopathogen, we suggest that authors provide at least three representative strains together with pathogenicity test results. If Koch’s postulates cannot be fulfilled, it is necessary to provide complementary data such as associated disease severity on the host plant. Moreover, more sequenced collections of species causing diseases should be published in order to stabilise the boundaries of cryptic species, species, subspecies, forms, and races.
This is a continuation of a series focused on providing a stable platform for the taxonomy of phytopathogenic fungi and fungus-like organisms. This paper focuses on one family:
Erysiphaceae
and 24 ...phytopathogenic genera:
Armillaria, Barriopsis
,
Cercospora
,
Cladosporium
,
Clinoconidium
,
Colletotrichum
,
Cylindrocladiella
,
Dothidotthia
,,
Fomitopsis
,
Ganoderma
,
Golovinomyces
,
Heterobasidium
,
Meliola
,
Mucor
,
Neoerysiphe
,
Nothophoma
,
Phellinus
,
Phytophthora
,
Pseudoseptoria
,
Pythium
,
Rhizopus
,
Stemphylium
,
Thyrostroma
and
Wojnowiciella.
Each genus is provided with a taxonomic background, distribution, hosts, disease symptoms, and updated backbone trees. Species confirmed with pathogenicity studies are denoted when data are available. Six of the genera are updated from previous entries as many new species have been described.
The deviation of conventional fungal niches is an important factor in the implications of hidden fungal diversity and global fungal numbers. The Xylariomycetidae (Sordariomycetes, Ascomycota), which ...is also referred to as xylarialean taxa, has a wide range of species that demonstrate a high degree of variation in their stromatic characteristics, showing either conspicuous or inconspicuous forms. In this study, samples were collected while focusing on temporal and spatial parameters and substrate characteristics. Based on internal transcribed spacer (ITS), 28S large subunit rDNA (LSU), RNA polymerase II second largest subunit (RPB2), and β-tubulin (TUB2) multigene phylogeny and morphology, five new species are introduced as Muscodor brunneascosporus, M. lamphunensis (Xylariaceae), Nigropunctata hydei, N. saccata (Incertae sedis), and Xenoanthostomella parvispora (Gyrotrichaceae). Plant substrates in the early stages of decay and attached to the host were feasible sample niches, with an emphasis on the collection of inconspicuous, hidden xylarialean species. The appearance of inconspicuous saprobic xylarialean forms during the rainy season may be linked to the change in nutritional mode, from endophytic mode during the dry season to saprobic in the wet. Therefore, it would be fascinating to concentrate future research on how seasonal fluctuations affect nutritional mode shifts, especially in northern Thailand, which would provide the optimal spatial characteristics. In order to establish a comprehensive linkage between endophytic and saprobic modes, it is imperative to have a substantial representation of endophytic isolate sequences resembling inconspicuous xylariaceous fungi within publicly accessible databases.
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