Fig 9 - uploaded by Uwe Braun
Content may be subject to copyright.
Rhynchosporium graminicola. A. Disease symptoms on Hordeum vulgaris. B-E. (CPC 39388). B-D. Hyphae with clusters of conidiogenous cells giving rise to conidia. E. Conidia. F-I. (CBS 135932). F-H. Hyphae with conidiogenous cells giving rise to conidia. I. Conidia. J-M. (CBS 483.50). J-L. Hyphae with conidiogenous cells giving rise to conidia. M. Conidia. N-R. (CBS 385.52). N-Q. Hyphae with conidiogenous cells giving rise to conidia. R. Conidia. Scale bars = 10 µm.
Source publication
The taxonomy of Oculimacula, Rhynchosporium and Spermospora is re-evaluated, along with that of phylogenetically
related genera. Isolates are identified using comparisons of DNA sequences of the internal transcribed spacer ribosomal
RNA locus (ITS), partial translation elongation factor 1-alpha (tef1), actin (act), DNA-directed RNA polymerase II la...
Citations
... The majority of scientific literature and studies consider R. secalis (sensu lato) as a monophyletic group with broad host range, mainly focusing on barley (Hordeum vulgare) as host and less on rye (Zhan et al., 2008). In recent years, the fungus causing scald on barley has been considered as a separate species from R. secalis and is now named R. graminicola Heinsen (before that R. commune) (Zaffarano et al., 2011;Crous et al., 2021). Typical leaf symptoms of scald on rye are water-soaked lesions of lenticular shape with a white-grey center and dark-brown margin (Caldwell, 1937). ...
Rye ( Secale cereale L .) is an important cereal crop used for food, beverages, and feed, especially in North-Eastern Europe. While rye is generally more tolerant to biotic and abiotic stresses than other cereals, it still can be infected by several diseases, including scald caused by Rhynchosporium secalis . The aims of this study were to investigate the genetic architecture of scald resistance, to identify genetic markers associated with scald resistance, which could be used in breeding of hybrid rye and to develop a model for genomic prediction for scald resistance. Four datasets with records of scald resistance on a population of 251 hybrid winter rye lines grown in 2 years and at 3 locations were used for this study. Four genomic models were used to obtain variance components and heritabilities of scald resistance. All genomic models included additive genetic effects of the parental components of the hybrids and three of the models included additive-by-additive epistasis and/or dominance effects. All models showed moderate to high broad sense heritabilities in the range of 0.31 (SE 0.05) to 0.76 (0.02). The model without non-additive genetic effects and the model with dominance effects had moderate narrow sense heritabilities ranging from 0.24 (0.06) to 0.55 (0.08). None of the models detected significant non-additive genomic variances, likely due to a limited data size. A genome wide association study was conducted to identify markers associated with scald resistance in hybrid winter rye. In three datasets, the study identified a total of twelve markers as being significantly associated with scald resistance. Only one marker was associated with a major quantitative trait locus (QTL) influencing scald resistance. This marker explained 11-12% of the phenotypic variance in two locations. Evidence of genotype-by-environment interactions was found for scald resistance between one location and the other two locations, which suggested that scald resistance was influenced by different QTLs in different environments. Based on the results of the genomic prediction models and GWAS, scald resistance seems to be a quantitative trait controlled by many minor QTL and one major QTL, and to be influenced by genotype-by-environment interactions.
... Единичные находки были сделаны в Дагестане (Баташева, 2018). (Crous et al., 2020). ...
Despite the great attention paid to the study of barley diseases, inaccuracies in the names of diseases, their practical significance, and incorrect use of the scientific names of causal agents can be commonly found in the scientific literature. This may lead to confusion and misidentification of the pathogens that can affect this crop especially as relates to phytosanitary requirements. This review continues the series started with a publication devoted to wheat diseases. This review includes information about the main barley diseases and pathogenic organisms causing them, as well as the species emerging as a potential threat to barley. The current taxonomic status of fungal species and fungal-like organisms associated with various organs of barley is given, and the breadth of their distribution and degree of impact on the crop are summarized. The micromycetes were divided into two groups according to their phytosanitary importance. The first group is represented by fungi of great importance as the pathogens causing the 29 economically important common barley diseases. The second group consists of fungi causing 20 minor and poorly studied diseases with unconfirmed harmfulness, or potential endophytic fungi. Perceptions of their ability to cause disease remain controversial and the available data require confirmation. This dataset can be used as a reference for a more accurate description of the phytosanitary situation. The review will also be helpful for more targeted studies using molecular techniques to clarify taxonomy and areals of fungi associated with barley and to provide more detailed data on disease damage in this crop.
... Researchers kept renaming this disease, the leaf blotch of barley caused by R. commune [15,42]. Based on nomenclatural priority, Crous et al. [9], recently suggested R. graminicola be replaced as the causal agent of R. commune. Phylogenetically, R. agropyri, R. graminicola, and R. secalis are closely related [9] (Fig. 2). ...
... Based on nomenclatural priority, Crous et al. [9], recently suggested R. graminicola be replaced as the causal agent of R. commune. Phylogenetically, R. agropyri, R. graminicola, and R. secalis are closely related [9] (Fig. 2). ...
... As the name implies, barely scald caused by R. graminicola [9] and wheat leaf blotch caused by Mycosphaerella graminicola [44,45] are identical at some taxonomic level. Both barley scald and wheat leaf blotch are similar at the species level (graminicola), but they are different at the genus level (Rhynchosporium for barley scald and Mycosphaerella for wheat leaf blotch). ...
Barley scald is very important in temperate and wet regions worldwide and has become one of the most important foliar diseases. Before the development of recent technologies, several scientists had argued that Rhynchosporium secalis is the causal agent of scald disease. However, the causal agent of this disease was revised and recognized as Rhynchosporium commune. Again recently, Rhynchosporium graminicola was suggested to be replaced as the causal agent of R. commune. The disease outbreak is depending on cool and frequent rainfall. Because of scald disease significance, numerous management practices have been advocated. Then, resistance materials, and mixing of resistant and susceptible cultivars have been used as the best management methods. Several studies have demonstrated that some cultivars and landraces of barley are resistant to scald disease during the seedling and adult growth stages. The first cultivar is “Atlas 46″ which was created from the cultivar “Turk”. From biological method: Bacillus polymyxa, Paenibacillus polymyxa KaI245, and Bacillus subtilis are very effective in treating this disease. Finally, as a last option, different fungicides have been suggested. Pathogenicity testing, seed treatments, tillage, cultivar mixtures, and biological control are all commonly overlooked in developing countries. Cultural practices such as times of fungicide application, appropriate time of sowing to scape disease, and tillage practices which are adopted for other diseases are greatly missed for scald disease. Then, we are intended to assess the various findings available on barley scald biology, taxonomy, and management.
... Therefore, wild grass species can serve as a reservoir of potentially virulent isolates and primary hosts to complete its sexual cycle (Linde et al. 2016;Seifollahi et al. 2018), whereas the secondary host remains unidentified. In a recent publication, Crous et al. (2021) proposed renaming R. commune to R. graminicola. ...
Key message
Rhynchosporium commune is a globally devastating pathogen of barley. Wild and landrace barley are underutilized, however, contain an abundance of loci that can be used as potential sources of resistance.
Abstract
Rhynchosporium commune, the causal agent of the disease scald or leaf blotch of barley, is a hemibiotrophic fungal pathogen of global importance, responsible for yield losses ranging from 30 to 40% on susceptible varieties. To date, over 150 resistance loci have been characterized in barley. However, due to the suspected location of the R. commune host jump in Europe, European germplasm has been the primary source used to screen for R. commune resistance leaving wild (Hordeum spontaneum) and landrace (H. vulgare) barley populations from the center of origin largely underutilized. A diverse population consisting of 94 wild and 188 barley landraces from Turkey were genotyped using PCR-GBS amplicon sequencing and screened with six Turkish R. commune isolates. The isolates were collected from distinct geographic regions of Turkey with two from the Aegean region, two from central Turkey and two from the Fertile Crescent region. The data set was utilized for association mapping analysis with a total of 21 loci identified, of which 12 were novel, indicating that these diverse primary barley gene pools contain an abundance of novel R. commune resistances that could be utilized for resistance breeding.
... For the Ascomycota phylum, these genes are considered better than rRNA genes to solve close relationships at different taxonomic and phylogenetic levels (Schoch et al. 2009). Among the protein-coding genes, the β-tubulin II gene (TUB2), cytochrome c oxidase subunit I (COX1) and subunit II (COX2), DNA-directed RNA polymerase II largest subunit (RPB1) and second largest subunit (RPB2), translational elongation factor 1α (TEF1), DNA topoisomerase I (TOP1), and phosphoglycerate kinase (PGK) have been proposed (Lücking et al. 2020;Crous et al. 2020). To classify Penicillium spp. ...
Endophytic fungi are microorganisms that colonize the interior of plant tissues (e.g. leaves, seeds, stem, trunk, roots, fruits, flowers) in intracellular and/or extracellular spaces without causing symptoms of disease in host plants. These microorganisms have been isolated from plant species in a wide variety of habitats worldwide, and it is estimated that all terrestrial plants are colonized by one or more species of endophytic fungus. In addition, these microorganisms have been drawing the attention of researchers because of their ability to synthesize a wide range of bioactive molecules with potential for applications in agriculture, medicine and biotechnology. However, several obstacles come up when studying the diversity and chemical potential of endophytic fungi. For example, the usage of an inappropriate surface disinfection method for plant tissue may not eliminate the epiphytic microbiota or may end up interfering with the endophytic mycobiota, which consequently generates erroneous results. Moreover, the composition of the culture medium and the culture conditions can favor the growth of certain species and inhibit others, which generates underestimated results. Other inconsistencies can arise from the fungus misidentification and consequent exploration of its chemical potential. Based on the methodological biases that may occur at all stages of studies dealing with endophytic fungi, the objective of this review is to discuss the main methods employed in these studies as well as highlight the challenges derived from the different approaches. We also report associated tips to help future studies on endophytic fungi as a contribution.
... Therefore, wild grass species can serve as a reservoir of potentially virulent isolates and primary hosts to complete its sexual cycle (Linde et al. 2016; Seifollahi et al. 2018), whereas the secondary host remains unidenti ed. In a recent publication, Crous et al. (2021) proposed renaming R. commune to R. graminicola. ...
Rhynchosporium commune, the causal agent of the disease scald or leaf blotch of barley is a hemibiotrophic fungal pathogen of global importance, responsible for yield losses ranging from 30-40% on susceptible varieties. To date, over 150 resistance loci have been characterized in barley. However, due to the suspected location of the R. commune host jump in Europe, European germplasm has been the primary source used to screen for R. commune resistance leaving wild ( Hordeum spontaneum ) and landrace ( H. vulgare ) barley populations from the center of origin largely underutilized. A diverse population consisting of 94 wild and 188 barley landraces from Turkey were genotyped using PCR-GBS amplicon sequencing and screened with six Turkish R. commune isolates. The isolates were collected from distinct geographic regions of Turkey with two from the Aegean region, two from central Turkey and two from the Fertile Crescent region. The data was utilized for association mapping analysis with a total of 21 loci identified, of which 13 were novel, indicating that these diverse primary barley gene pools contain an abundance of novel R. commune resistances that could be utilized for resistance breeding.
... Asci cylindrical to clavate, tapered towards the apex, narrowed to a short stalk, 37-60 × 4 -6 μm, 8-spored. Ascospores hyaline, cylindrical to fusiform, rounded at the ends, straight or rarely slightly curved, aseptate or rarely 1-septate, 7-11 × 1.5 -2 μm (adapted from Wallwork & Spooner 1988 Notes -Oculimacula yallundae (Crous et al. , 2021a was listed in the Chinese quarantine pest directory as Pseudo cercosporella herpotrichoides and therefore assumed to be a member of Dothideomycetes. However, the phylogeny of this pathogen has since been resolved as belonging to Ploettnerula ceae (Helotiales). ...
... Severe cases of the eyespot disease can reduce yield by up to 50 % (Fitt et al. 1988). In addition to O. yallundae, O. acuformis is also associated with eyespot disease of cereals in temperate regions, and their phylogenetic relationship was inferred in Marin-Felix et al. (2019b) and Crous et al. (2021a). Symptoms -Leaf spots oval, frequently coalescing, straw or buff coloured, central portion bearing pycnidial conidiomata, often grey to black (Johnson 1947). ...
The current list of Chinese quarantine pests includes 130 fungal species. However, recent changes in the taxonomy of fungi following the one fungus = one name initiative and the implementation of DNA phylogeny in taxonomic revisions, resulted in many changes of these species names, necessitating an update of the current list. In addition, many quarantine fungi lack modern morphological descriptions and authentic DNA sequences, posing significant challenges for the development of diagnostic protocols. The aim of the present study was to review the taxonomy and names of the 33 Chinese quarantine fungi in Dothideomycetes , and provide reliable DNA barcodes to facilitate rapid identification. Of these, 23 names were updated according to the single name nomenclature system, including one new combination, namely Cophinforma tumefaciens comb. nov. (syn. Sphaeropsis tumefaciens ). On the basis of phylogenetic analyses and morphological comparisons, a new genus Xenosphaeropsis is introduced to accommodate the monotypic species Xenosphaeropsis pyriputrescens comb. nov. (syn. Sphaeropsis pyriputrescens ), the causal agent of a post-harvest disease of pears. Furthermore, four lectotypes ( Ascochyta petroselini , Mycosphaerella ligulicola , Physalospora laricina , Sphaeria lingam ), three epitypes ( Ascochyta petroselini , Phoma lycopersici , Sphaeria lingam ), and two neotypes ( Ascochyta pinodella , Deuterophoma tracheiphila ) are designated to stabilise the use of these names. A further four reference strains are introduced for Cophinforma tumefaciens , Helminthosporium solani , Mycocentrospora acerina , and Septoria linicola . In addition, to assist future studies on these important pathogens, we sequenced and assembled whole genomes for 17 species, including Alternaria triticina , Boeremia foveata , B. lycopersici , Cladosporium cucumerinum , Didymella glomerata , Didymella pinodella , Diplodia mutila , Helminthosporium solani , Mycocentrospora acerina , Neofusicoccum laricinum , Parastagonospora pseudonodorum , Plenodomus libanotidis , Plenodomus lingam , Plenodomus tracheiphilus , Septoria petroselini , Stagonosporopsis chrysanthemi , and Xenosphaeropsis pyriputrescens .
... J.J. Davis) (Zaffarano et al. 2011) is one of the most important diseases worldwide (Avrova and Knogge 2012;Zhang et al. 2020). The name R. graminicola Heinsen 1897 is also suggested to be used as a replacing synonym for R. commune due to its longer history (Crous et al. 2021). R. commune is the causal agent of barley scald, also known as leaf scald, leaf blotch or Rhynchosporium. ...
Genome-Wide Association Studies (GWAS) of four Multi-parent Advanced Generation Inter-Cross (MAGIC) populations identified nine regions on chromosomes 1H, 3H, 4H, 5H, 6H and 7H associated with resistance against barley scald disease. Three of these regions are putatively novel resistance Quantitative Trait Loci (QTL). Barley scald is caused by Rhynchos-porium commune, one of the most important barley leaf diseases that are prevalent in most barley-growing regions. Up to 40% yield losses can occur in susceptible barley cultivars. Four MAGIC populations were generated in a Nordic Public-Private Pre-breeding of spring barley project (PPP Barley) to introduce resistance to several important diseases. Here, these MAGIC populations consisting of six to eight founders each were tested for scald resistance in field trials in Finland and Iceland. Eight different model covariate combinations were compared for GWAS studies, and the models that deviated the least from the expected p-values were selected. For all QTL, candidate genes were identified that are predicted to be involved in pathogen defence. The MAGIC progenies contained new haplotypes of significant SNP-markers with high resistance levels. The lines with successfully pyramided resistance against scald and mildew and the significant markers are now distributed among Nordic plant breeders and will benefit development of disease-resistant cultivars.
Introduction
We now recognize that plant genotype affects the assembly of its microbiome, which in turn, affects essential plant functions. The production system for crop plants also influences the microbiome composition, and as a result, we would expect to find differences between conventional and organic production systems. Plant genotypes selected in an organic regime may host different microbiome assemblages than those selected in conventional environments. We aimed to address these questions using recombinant inbred populations of snap bean that differed in breeding history.
Methods
Rhizosphere microbiomes of conventional and organic common beans ( Phaseolus vulgaris L.) were characterized within a long-term organic research site. The fungal and bacterial communities were distinguished using pooled replications of 16S and ITS amplicon sequences, which originated from rhizosphere samples collected between flowering and pod set.
Results
Bacterial communities significantly varied between organic and conventional breeding histories, while fungal communities varied between breeding histories and parentage. Within the organically-bred populations, a higher abundance of a plant-growth-promoting bacteria, Arthrobacter pokkalii , was identified. Conventionally-bred beans hosted a higher abundance of nitrogen-fixing bacteria that normally do not form functional nodules with common beans. Fungal communities in the organically derived beans included more arbuscular mycorrhizae, as well as several plant pathogens.
Discussion
The results confirm that the breeding environment of crops can significantly alter the microbiome community composition of progeny. Characterizing changes in microbiome communities and the plant genes instrumental to these changes will provide essential information about how future breeding efforts may pursue microbiome manipulation.
Rhynchosporium is a wide spread disease in the regions of winter rye cultivation. The paper demonstrates the results of the monitoring of occurrence and development of phytopathogene in the crop in the Republic of Belarus for 2019-2020.
