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Zymoseptoria tritici , the causal agent of Septoria tritici blotch (STB) in bread wheat ( Triticum aestivum ), leads to significant global yield losses. Resistance breeding is vital for managing STB, but there is limited information on Z. tritici infection behaviour in Ethiopia. This study examined the virulence variability of Z. tritici isolates from Ethiopia’s Central Highlands and evaluated the effectiveness of known wheat STB-resistance genes. Eight wheat lines were tested against six Z. tritici isolates, showing significant differences ( p  < 0.0001) in necrotic leaf area (%NLA) and pycnidia coverage (%PC) among the tested Z. tritici isolates, wheat lines and their interactions. Wheat genotype TE9111 exhibited specific resistance to 50% of the isolates, while Taichung 29 showed no resistance. Isolate ZSE158 was the most aggressive, causing 61.4% PC and 54% NLA. The Ethiopian isolates displayed broad virulence against resistance genes, including Stb2 – Stb7. TE9111, carrying Stb11, showed resistance to 50% of isolates, making it a valuable source for resistance breeding against STB. This study identified highly virulent pathogen isolates useful for wheat germplasm screening for STB resistance and also key resistance source materials for use in wheat resistance breeding in Ethiopia.

The necrotrophic fungus Ascochyta rabiei causes Ascochyta blight (AB) disease in chickpea. A. rabiei infects all aerial parts of the plant, which results in severe yield loss. At present, AB disease occurs in most chickpea‐growing countries. Globally increased incidences of A. rabiei infection and the emergence of new aggressive isolates directed the interest of researchers toward understanding the evolution of pathogenic determinants in this fungus. In this review, we summarize the molecular and genetic studies of the pathogen along with approaches that are helping in combating the disease. Possible areas of future research are also suggested. Taxonomy kingdom Mycota, phylum Ascomycota, class Dothideomycetes, subclass Coelomycetes, order Pleosporales, family Didymellaceae, genus Ascochyta, species rabiei. Primary host A. rabiei survives primarily on Cicer species. Disease symptoms A. rabiei infects aboveground parts of the plant including leaves, petioles, stems, pods, and seeds. The disease symptoms first appear as watersoaked lesions on the leaves and stems, which turn brown or dark brown. Early symptoms include small circular necrotic lesions visible on the leaves and oval brown lesions on the stem. At later stages of infection, the lesions may girdle the stem and the region above the girdle falls off. The disease severity increases at the reproductive stage and rounded lesions with concentric rings, due to asexual structures called pycnidia, appear on leaves, stems, and pods. The infected pod becomes blighted and often results in shrivelled and infected seeds. Disease management strategies Crop failures may be avoided by judicious practices of integrated disease management based on the use of resistant or tolerant cultivars and growing chickpea in areas where conditions are least favourable for AB disease development. Use of healthy seeds free of A. rabiei, seed treatments with fungicides, and proper destruction of diseased stubbles can also reduce the fungal inoculum load. Crop rotation with nonhost crops is critical for controlling the disease. Planting moderately resistant cultivars and prudent application of fungicides is also a way to combat AB disease. However, the scarcity of AB‐resistant accessions and the continuous evolution of the pathogen challenges the disease management process. Useful websites https://www.ndsu.edu/pubweb/pulse‐info/resourcespdf/Ascochyta%20blight%20of%20chickpea.pdf https://saskpulse.com/files/newsletters/180531_ascochyta_in_chickpeas‐compressed.pdf http://www.pulseaus.com.au/growing‐pulses/bmp/chickpea/ascochyta‐blight http://agriculture.vic.gov.au/agriculture/pests‐diseases‐and‐weeds/plant‐diseases/grains‐pulses‐and‐cereals/ascochyta‐blight‐of‐chickpea http://www.croppro.com.au/crop_disease_manual/ch05s02.php https://www.northernpulse.com/uploads/resources/722/handout‐chickpeaascochyta‐nov13‐2011.pdf http://oar.icrisat.org/184/1/24_2010_IB_no_82_Host_Plant https://www.crop.bayer.com.au/find‐crop‐solutions/by‐pest/diseases/ascochyta‐blight This study presents a detailed overview of the pathology of a devastating necrotrophic fungus, Ascochyta rabiei, that infects all the aerial parts of chickpea and causes Ascochyta blight disease.

Gummy stem blight (GSB) is a major disease of cucurbits worldwide. It is caused by three fungal species that are morphologically identical and have overlapping geographic and host ranges. Controlling GSB is challenging due to the lack of resistant cultivars and the pathogens' significant ability to develop resistance to systemic fungicides. The causal agent of GSB is recognized as a complex of three phylogenetically distinct species belonging to domain Eukaryota, kingdom Fungi, phylum Ascomycota, subphylum Pezizomycotina, class Dothideomycetes, subclass Pleosporomycetida, order Pleosporales, family Didymellaceae, genus Stagonosporopsis, species cucurbitacearum, citrulli, and caricae. Pycnidia are tan with dark rings of cells around the ostiole measuring 120–180 μm in diameter. Conidia are 6–13 μm long, hyaline, cylindrical with round ends, and non‐ or monoseptate. Pseudothecia are black and globose in shape and have a diameter of 125–213 μm. Ascospores are 14–18 × 4–6 μm long, hyaline, ellipsoidal with round ends, and monoseptate with a distinct constriction at the septum. Eight ascospores are found per ascus. The upper end of the apical cell is pointed, whereas the lower end of the bottom cell is blunt. Species‐specific PCR primers that can be used in a multiplex conventional PCR assay are available. The GSB species complex is pathogenic to 37 species of cucurbits from 21 different genera. S. cucurbitacearum and S. citrulli are specific to cucurbits, while S. caricae is also pathogenic to papaya and babaco‐mirim (Vasconcellea monoica), a related fruit. Under favourable environmental conditions, symptoms can appear 3–12 days after spore germination. Leaf spots often start at the leaf margin or extend to the margins. Spots expand and coalesce, resulting in leaf blighting. Active lesions are typically water‐soaked. Cankers are observed on crowns, main stems, and vines. Red to amber gummy exudates are often seen on the stems after cankers develop on cortical tissue. Gummy stem blight is an important disease of many cucurbit crops worldwide; the causal agents are three species of Stagonosporopsis with identical morphology and overlapping host ranges.

Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici , is among the most threatening wheat diseases in Europe. Genetic resistance remains one of the main environmentally sustainable strategies to efficiently control STB. However, the molecular and physiological mechanisms underlying resistance are still unknown, limiting the implementation of knowledge-driven management strategies. Among the 22 known major resistance genes ( Stb ), the recently cloned Stb16q gene encodes a cysteine-rich receptor-like kinase conferring a full broad-spectrum resistance against Z. tritici . Here, we showed that an avirulent Z. tritici inoculated on Stb16q quasi near isogenic lines (NILs) either by infiltration into leaf tissues or by brush inoculation of wounded tissues partially bypasses Stb16q -mediated resistance. To understand this bypass, we monitored the infection of GFP-labeled avirulent and virulent isolates on Stb16q NILs, from germination to pycnidia formation. This quantitative cytological analysis revealed that 95% of the penetration attempts were unsuccessful in the Stb16q incompatible interaction, while almost all succeeded in compatible interactions. Infectious hyphae resulting from the few successful penetration events in the Stb16q incompatible interaction were arrested in the sub-stomatal cavity of the primary-infected stomata. These results indicate that Stb16q -mediated resistance mainly blocks the avirulent isolate during its stomatal penetration into wheat tissue. Analyses of stomatal aperture of the Stb16q NILs during infection revealed that Stb16q triggers a temporary stomatal closure in response to an avirulent isolate. Finally, we showed that infiltrating avirulent isolates into leaves of the Stb6 and Stb9 NILs also partially bypasses resistances, suggesting that arrest during stomatal penetration might be a common major mechanism for Stb -mediated resistances.

Grapevine trunk diseases constitute a significant phytopathological concern in Egyptian viticulture, with ongoing debates regarding their origin and transmission dynamics. These complexities are attributed to the heterogeneous manifestation of symptoms and the involvement of multiple wood-associated pathogens, both suspected and confirmed. This study investigates the mycological aspects of grapevine trunk diseases, focusing on Lasiodiplodia theobromae as a causal agent. The pathogen was associated with vascular cankers, dark brown trunk discoloration, pycnidia formation on necrotic tissues, and grapevine dieback. Identification of L. theobromae was achieved through morphological characteristics and molecular analysis targeting the β-tubulin gene and Internal Transcribed Spacer (ITS) region. Pathogenicity tests were conducted by inoculating detached canes, leaves, petioles, and entire branches with mycelial plugs of L. theobromae . The resulting symptoms closely resembled those observed in naturally infected grapevines in the field. The pathogen was then re-isolated and identified, confirming Koch’s postulates. A disease index (DI) ranging from 60 to 100% provided strong evidence of the high pathogenic potential of L. theobromae under experimental conditions.

Phomopsis cane and leaf spot (PCLS) disease, affecting grapevines ( Vitis vinifera and Vitis spp.), has been historically associated with Diaporthe ampelina . Typical disease symptoms, comprising bleaching and black pycnidia, have also been associated with other Diaporthe spp. In this study, we conducted a molecular identification of the Diaporthe isolates isolated from grapevine canes from different geographic areas of southern Europe showing PCLS symptoms. Then, we investigated their morphological characteristics (including mycelium growth and production of pycnidia and alpha and beta conidia) in response to temperature. Finally, we artificially inoculated grapevine shoots and leaves with a subset of these isolates. Based on our results, PCLS etiology should be reconsidered. Though D. ampelina was the most crucial causal agent of PCLS, D. eres and D. foeniculina were also pathogenic when inoculated on green shoots and leaves of grapevines. However, D. rudis was not pathogenic. Compared to D. ampelina , D. eres and D. foeniculina produced both pycnidia and alpha conidia at lower temperatures. Thus, the range of environmental conditions favorable for PCLS development needs to be widened. Our findings warrant further validation by future studies aimed at ascertaining whether the differences in temperature requirements among species are also valid for conidia-mediated infection since it could have substantial practical implications in PCLS management.

Zymoseptoria tritici is an ascomycete fungus and the causal agent of Septoria tritici leaf blotch (STB) in wheat. Z . tritici secretes an array of effector proteins that are likely to facilitate host infection, colonisation and pycnidia production. In this study we demonstrate a role for Zt-11 as a Z . tritici effector during disease progression. Zt-11 is upregulated during the transition of the pathogen from the biotrophic to necrotrophic phase of wheat infection. Deletion of Zt-11 delayed disease development in wheat, reducing the number and size of pycnidia, as well as the number of macropycnidiospores produced by Z . tritici . This delayed disease development by the Δ Zt-11 mutants was accompanied by a lower induction of PR genes in wheat, when compared to infection with wildtype Z . tritici . Overall, these data suggest that Zt-11 plays a role in Z . tritici aggressiveness and STB disease progression possibly via a salicylic acid associated pathway.

In 2019, during May to September a unique lichen occurring on soil was collected from four different localities in Deosai National Park, Gilgit-Baltistan, Pakistan. Phylogenetic analysis of the nrDNA ITS and LSU regions revealed that it clustered within the genus Placidium. Further morpho-anatomical and chemical analyses proved its novelty, and it is here described as a new species under the name P. deosaiense. The distinguishing characters of this novel taxon are brown to blackish 2–7 mm wide squamules, undulating in the center, epruinose at margins, epinecral layer up to 70 µm, cylindrical asci with ellipsoid to narrowly ellipsoid ascospores and clavate to bacilliform pycnidiospores.

Many fungi require specific growth conditions before they can be identified. Direct environmental DNA sequencing is advantageous, although for some taxa, specific primers need to be used for successful amplification of molecular markers. The internal transcribed spacer region is the preferred DNA barcode for fungi. However, inter- and intra-specific distances in ITS sequences highly vary among some fungal groups; consequently, it is not a solely reliable tool for species delineation. Ampelomyces , mycoparasites of the fungal phytopathogen order Erysiphales , can have ITS genetic differences up to 15%; this may lead to misidentification with other closely related unknown fungi. Indeed, Ampelomyces were initially misidentified as other pycnidial mycoparasites, but subsequent research showed that they differ in pycnidia morphology and culture characteristics. We investigated whether the ITS2 nucleotide content and secondary structure was different between Ampelomyces ITS2 sequences and those unrelated to this genus. To this end, we retrieved all ITS sequences referred to as Ampelomyces from the GenBank database. This analysis revealed that fungal ITS environmental DNA sequences are still being deposited in the database under the name Ampelomyces , but they do not belong to this genus. We also detected variations in the conserved hybridization model of the ITS2 proximal 5.8S and 28S stem from two Ampelomyces strains. Moreover, we suggested for the first time that pseudogenes form in the ITS region of this mycoparasite. A phylogenetic analysis based on ITS2 sequences-structures grouped the environmental sequences of putative Ampelomyces into a different clade from the Ampelomyces -containing clades. Indeed, when conducting ITS2 analysis, resolution of genetic distances between Ampelomyces and those putative Ampelomyces improved. Each clade represented a distinct consensus ITS2 S2, which suggested that different pre-ribosomal RNA (pre-rRNA) processes occur across different lineages. This study recommends the use of ITS2 S2s as an important tool to analyse environmental sequencing and unveiling the underlying evolutionary processes.