Uneven distribution of mating type alleles in Iranian populations of Cercospora beticola, the causal agent of Cercospora leaf spot disease of sugar beet

Cercospora beticola, the causal agent of Cercospora leaf spot disease on sugar beet, is thought to be exclusively asexual because no teleomorph has yet been found. The possibility of a clandestine sexual cycle in the Iranian population of Cercospora beticola was evaluated by analyzing the distribution and frequency of the mating type alleles on a microspatial and a macrogeographical scale. A total of 89 single-conidial Cercospora beticola isolates were obtained from sugar beet fields in the Moghan, the Talesh and the Khoy regions. The isolates were identifed using a Cercospora beticola-specifc primer set in a PCR assay. A multiplex PCR method using previously designed mating type primers was used to study the distribution and the frequency of the mating type alleles. All isolates showed either the 805-bp fragment or the 442-bp fragment of the MAT1-1 and MAT1-2 genes, but no isolate had both fragments. The distribution of the mating type genes in the sampled areas was uneven. From three sugar beet fields sampled in the Moghan region, two fields had only MAT1-1 isolates; while in the third field all isolates had only the MAT1-2 allele. In the Talesh region only MAT1-1 isolates occurred, and in the Khoy region the mating type alleles were uniformly distributed amongst the isolates. The skewed distribution of mating type alleles in Northwestern Iran was in line with the lack of a sexual cycle for this species and may also indicate that sugar fields in the Moghan region were infected by C. beticola populations of different origins

Genera of Phytopathogenic Fungi: GOPHY 4

This paper is the fourth contribution in the Genera of Phytopathogenic Fungi (GOPHY) series. The series provides morphological descriptions and information about the pathology, distribution, hosts and disease symptoms, as well as DNA barcodes for the taxa covered. Moreover, 12 whole-genome sequences for the type or new species in the treated genera are provided. The fourth paper in the GOPHY series covers 19 genera of phytopathogenic fungi and their relatives, including Ascochyta, Cadophora, Celoporthe, Cercospora, Coleophoma, Cytospora, Dendrostoma, Didymella, Endothia, Heterophaeomoniella, Leptosphaerulina, Melampsora, Nigrospora, Pezicula, Phaeomoniella, Pseudocercospora, Pteridopassalora, Zymoseptoria, and one genus of oomycetes, Phytophthora. This study includes two new genera, 30 new species, five new combinations, and 43 typifications of older names.The study of Ascochyta, Didymella and Leptosphaerulina were supported by the National Natural Science Foundation of China (31750001) and the National Science and Technology Fundamental Resources Investigation Program of China (MOST: 2021FY100900). The study of the genus Phytophthora was supported by the Project Phytophthora Research Centre Reg. No. CZ.02.1.01/0.0/0.0/15_003/000 0453 cofinanced by the European Regional Development Fund. ShuaiFei Chen acknowledges the National Key R&D Program of China (ChinaSouth Africa Forestry Joint Research Centre Project; 2018YFE0120900) for financial support. Mounes Bakhshi and Rasoul Zare gratefully acknowledge the Iran National Science Foundation (INSF), and Research Deputy of the Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), for financial support. The study of the genera Pseudocercospora and Pteridopassalora were partially supported by JSPS KAKENHI Grant Numbers JP20K06146 to Chiharu Nakashima

Fusarium and allied fusarioid taxa (FUSA). 1

Seven Fusarium species complexes are treated, namely F. aywerte species complex (FASC) (two species), F. buharicum species complex (FBSC) (five species), F. burgessii species complex (FBURSC) (three species), F. camptoceras species complex (FCAMSC) (three species), F. chlamydosporum species complex (FCSC) (eight species), F. citricola species complex (FCCSC) (five species) and the F. concolor species complex (FCOSC) (four species). New species include Fusicolla elongata from soil (Zimbabwe), and Neocosmospora geoasparagicola from soil associated with Asparagus officinalis (Netherlands). New combinations include Neocosmospora akasia, N. awan, N. drepaniformis, N. duplosperma, N. geoasparagicola, N. mekan, N. papillata, N. variasi and N. warna. Newly validated taxa include Longinectria gen. nov., L. lagenoides, L. verticilliforme, Fusicolla gigas and Fusicolla guangxiensis. Furthermore, Fusarium rosicola is reduced to synonymy under N. brevis. Finally, the genome assemblies of Fusarium secorum (CBS 175.32), Microcera coccophila (CBS 310.34), Rectifusarium robinianum (CBS 430.91), Rugonectria rugulosa (CBS 126565), and Thelonectria blattea (CBS 952.68) are also announced her

Fusarium: more than a node or a foot-shaped basal cell

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org)

Uneven distribution of mating type alleles in Iranian populations of <I>Cercospora beticola</I>, the causal agent of Cercospora leaf spot disease of sugar beet

Cercospora beticola, the causal agent of Cercospora leaf spot disease on sugar beet, is thought to be exclusively asexual because no teleomorph has yet been found. The possibility of a clandestine sexual cycle in the Iranian population of Cercospora beticola was evaluated by analyzing the distribution and frequency of the mating type alleles on a microspatial and a macrogeographical scale. A total of 89 single-conidial Cercospora beticola isolates were obtained from sugar beet fields in the Moghan, the Talesh and the Khoy regions. The isolates were identifed using a Cercospora beticola-specifc primer set in a PCR assay. A multiplex PCR method using previously designed mating type primers was used to study the distribution and the frequency of the mating type alleles. All isolates showed either the 805-bp fragment or the 442-bp fragment of the MAT1-1 and MAT1-2 genes, but no isolate had both fragments. The distribution of the mating type genes in the sampled areas was uneven. From three sugar beet fields sampled in the Moghan region, two fields had only MAT1-1 isolates; while in the third field all isolates had only the MAT1-2 allele. In the Talesh region only MAT1-1 isolates occurred, and in the Khoy region the mating type alleles were uniformly distributed amongst the isolates. The skewed distribution of mating type alleles in Northwestern Iran was in line with the lack of a sexual cycle for this species and may also indicate that sugar fields in the Moghan region were infected by C. beticola populations of different origins

Inhibitory effects of antagonistic bacteria inhabiting the rhizosphere of the sugarbeet plants, on Cercospora beticola Sacc., the causal agent of Cercospora leaf spot disease on sugarbeet

In the present study, the antagonistic capability of bacterial agents inhabiting the rhizosphere of sugarbeet plants were evaluated against Cercospora beticola Sacc. under laboratory and greenhouse conditions. After preliminary screening using the dual culture method, 14 strains with higher antagonistic capability were selected for further inhibitory assays against C. beticola. Bacterial strains were identified based on the sequence data of the small subunit-rDNA (SSU-rDNA) gene. Based on the SSU sequence data, the identity of bacterial strains were determined as Bacillus (10 strains: RB1, RB2, RB3, RB4, RB5, RB6, RB7, RB8, RB9, RB10), Paenibacillus (two strains: RP1, RP2), Enterobacter (one strain: RE), and Pseudomonas (one strain: RPs). The results obtained in this study showed that in all of the assays (dual culture, volatile and non-volatile metabolites) bacterial antagonists significantly inhibited the growth of C. beticola compared to the control. Bacillus (RB2) showed the highest inhibition rate on C. beticola in all of the assays. Based on the results of the laboratory assays, three bacterial strains RB2 (Bacillus), RPs (Pseudomonas), and RE (Paenibacillus) were selected for greenhouse assays. The experiment was designed based on a completely randomised design (CRD) with the application of antagonists prior to, simultaneously, and after inoculation with C. beticola on sugarbeet leaves. The reduction in disease severity was evaluated seven days after inoculation. The results of greenhouse assays were consistent with the results of laboratory studies. The obtained results showed that bacterial antagonists significantly reduced the disease severity when compared to the control

Parastagonosporella fallopiae gen. et sp. nov. (Phaeosphaeriaceae) on Fallopia convolvulus from Iran

Phaeosphaeriaceae is a species-rich family in the order Pleosporales, encompassing species with diverse lifestyles viz., endophytic, epiphytic, lichenicolous, phytopathogenic, saprobic and even human pathogenic. In a survey on biodiversity of fungal species associated with leaf spot diseases of herbaceous plants in Iran, a coelomycetous fungus was recovered from symptomatic leaves of Fallopia convolvulus. Morphologically, the fungal isolates resembled species in the genus Parastagonospora. Although the phylogenetic analysis based on combined LSU and ITS sequence data placed these isolates within the family Phaeosphaeriaceae, they clustered distinct from presently known genera in the family. The monotypic genus Parastagonosporella (Phaeosphaeriaceae) is therefore introduced, with Parastagonosporella fallopiae as type species. A detailed description is provided, with notes discussing allied genera in the family.</p

Novel primers improve species delimitation in Cercospora

The genus Cercospora includes many important plant pathogens that are commonly associated with leaf spot diseases on a wide range of cultivated and wild plant species. Due to the lack of useful morphological features and high levels of intraspecific variation, host plant association has long been a decisive criterion for species delimitation in Cercospora. Because several taxa have broader host ranges, reliance on host data in Cercospora taxonomy has proven problematic. Recent studies have revealed multi-gene DNA sequence data to be highly informative for species identification in Cercospora, especially when used in a concatenated alignment. In spite of this approach, however, several species complexes remained unresolved as no single gene proved informative enough to act as DNA barcoding locus for the genus. Therefore, the aims of the present study were firstly to improve species delimitation in the genus Cercospora by testing additional genes and primers on a broad set of species, and secondly to find the best DNA barcoding gene(s) for species delimitation. Novel primers were developed for tub2 and rpb2 to supplement previously published primers for these loci. To this end, 145 Cercospora isolates from the Iranian mycobiota together with 25 additional reference isolates preserved in the Westerdijk Fungal Biodiversity Institute were subjected to an eight-gene (ITS, tef1, actA, cmdA, his3, tub2, rpb2 and gapdh) analysis. Results from this study provided new insights into DNA barcoding in Cercospora, and revealed gapdh to be a promising gene for species delimitation when supplemented with cmdA, tef1 and tub2. The robust eight-gene phylogeny revealed several novel clades within the existing Cercospora species complexes, such as C. apii, C. armoraciae, C. beticola, C. cf. flagellaris and Cercospora sp. G. The C. apii s. lat. isolates are distributed over three clades, namely C. apii s. str., C. plantaginis and C. uwebrauniana sp. nov. The C. armoraciae s. lat. isolates are distributed over two clades, C. armoraciae s. str. and C. bizzozeriana. The C. beticola s. lat. isolates are distributed over two clades, namely C. beticola s. str. and C. gamsiana, which is newly described

New species of Septoria associated with leaf spot diseases in Iran

Species of Septoria are commonly associated with leaf spot diseases of a broad range of plant hosts worldwide. During our investigation of fungi associated with leaf spot diseases in northern and northwestern Iran, several Septoria isolates were recovered from symptomatic leaves on different herbaceous and woody plants in the Asteraceae, Betulaceae, and Salicaceae families. These isolates were studied by applying a polyphasic approach including morphological and cultural data and a multigene phylogeny using a combined data set of partial sequences of the 28S nuc rRNA gene (large subunit [28S]), internal transcribed spacer regions and intervening 5.8S nuc rRNA gene (ITS) of the nuc rDNA operon, actin (actA), translation elongation factor 1-α (tef1), calmodulin (cmdA), β-tubulin (tub2), and DNA-directed RNA polymerase II second largest subunit (rpb2). Four novel species are proposed, namely, Septoria eclipticola on Eclipta prostrata, Septoria firouraghina on Cirsium arvense, Septoria guilanensis on Populus deltoides, and Septoria taleshana on Alnus subcordata. All species are illustrated, and their morphology and phylogenetic relationships with other Septoria species are discussed.</p

* گزارش مقدماتی از هیفومیستهاي آبزي تالاب انزلی (استان گیلان)

Aquatic hyphomycetes equipped with a rich array of extracellular enzymes are involved in bioremediation of anthropogenic pollutants, plastics, aromatic contaminants and petroleum hydrocarbons. The current study contributes to the knowledge of Iranian aquatic hyphomycetes. Sampling was conducted in Anzali lagoon, Gilan province, Iran during 2017. Among 55 fungal isolates obtained during this study, eight species including Arthrobotrys oligosporus, Ceratorhiza hydrophila, Fusarium cf. ensiforme, F. incarnatum species complex, Myrmecridium schulzeri, Paecilomyces variotii, Sarocladium subulatum, and Volutella citrinella were identified based on their morphological characteristics. Furthermore, three species assigned to the genera Arthrobotrys, Fusarium and Sarocladium remained unidentified. Molecular studies using mainly ITS, LSU and SSU rDNA and in some cases β-tubulin (tub2) and translation elongation factor 1-a (tef1) determined the phylogenetic position of the isolates among closely related species. The occurrence of members of Fusarium, Sarocladium, and Ceratorhiza, known as rice disease agents, in freshwater ecosystems is interesting. This is the first report of aquatic hyphomycetes communities in Anzali lagoon, Iran. In this study, Sarocladium subulatum, Myrmecridium schulzeri, and Volutella citrinella are reported for the first time for Iran.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí