Turf-grasses are economically important horticultural crops, which have been utilised by humans to improve the environment for more than a thousand years. Turf-grasses are widely distributed in landscapes, slopes and sport fields, such as golf courses. Endophytic fungi are a resource of unexplored fungal diversity with potential bioactive compounds. In this study, culture-independent ITS amplicon sequencing and culture-dependent isolation methods were used to reveal fungal community in roots of the turf-grass Zoysia japonica. A total of 317 OTUs were identified from root samples of Z. japonica by analysis of ITS amplicon reads. Fungal community was dominated by Sordariales (32.45%), followed by Chaetothyriales (18.16%), unknown taxa in Sordariomycetes (14.63%) and Pleosporales (12.48%). During isolation, 151 endophytic fungal strains were obtained from roots of Z. japonica and a variety of taxa were found by ITS amplification and sequencing. Moreover, 11 endophytic fungal species were further characterised in this study, based on morphological characterisation and multi-loci phylogenetic analysis, including Niesslia dimorphospora, a newly-recorded species in Korea and 10 novel species (Dactylaria hwasunensissp. nov., Lophiostoma jeollanense sp. nov., Magnaporthiopsis zoysiaesp. nov., Poaceascoma endophyticumsp. nov., P. koreanumsp. nov., P. magnumsp. nov., P. zoysiiradicicolasp. nov., Stagonospora endophytica sp. nov., Setophoma zoysiaesp. nov. and Pseudorhypophila poaesp. nov.). Antifungal activities of these species were tested against the turf-grass brown patch pathogen Rhizoctonia solani AG2-2(IIIB), with S. zoysiae being the best antagonist. In addition, butanol extract from mycelia of S. zoysiae strongly inhibited R. solani AG2-2(IIIB) in vitro and in planta. The results of this study expand the biodiversity of endophytic fungi and revealed potential biological resources for future turf-grass management and bioactive compound exploitation.

BACKGROUND: Gray mold caused by Botrytis cinerea is one of the most serious diseases affecting strawberry. Succinate dehydrogenase inhibitor (SDHI) fungicides have been used for more than a decade to control the disease. Monitoring resistance and improving in‐depth understanding of resistance mechanisms are essential for the control of B. cinerea.RESULTS: In this study, resistance monitoring of a SDHI fungicide boscalid was conducted on B. cinerea isolated from strawberries in Korea during 2020 and 2021, with resistance rates of 76.92% and 72.25%, respectively. In resistant strains, mutations P225F/H and H272R were found in SdhB, with P225F representing the dominant mutation type. Simultaneous mutations G85A, I93V, M158V, and V168I in SdhC were detected in 54.84% of sensitive strains. Sensitivity profiles of different Sdh genotypes of B. cinerea strains to six SDHIs were determined in vitro and in vivo. In addition, the mutation(s) were genetically validated through in situ SdhB (SdhC) expression. Docking assays between SDHIs and AlphaFold model‐based Sdh complexes revealed generally consistent patterns with their in vitro phenotypes.CONCLUSION: Resistance of B. cinerea to SDHI fungicide on strawberry was systematically investigated in this study. Deciphering of SDHI resistance through the genetic transformation system and AlphaFold model‐based molecular docking will provide valuable insights into other target site‐based fungicide resistance in fungal pathogens. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Citrus sinensis is an important fruit crop valued for its juicy fruit pulp and aromatic rind. Grafted twigs with rot progressing from both ends were observed on C. sinensis trees in 12 orchards in Zigui, China, in June 2017, with only 5% of grafted twigs surviving in some orchards. Severe infection resulted in a rot of the entire twig, with the twig becoming covered by a white mycelium. A fungus frequently recovered from the diseased twigs was identified as Fusarium solani based on cultural and conidial characteristics. Multi-gene phylogenetic analysis including partial gene sequences of the internal transcribed spacer (ITS) region of rDNA, translation-elongation factor 1 alpha (EF-1ɑ) and the RNA polymerase second largest subunit (RPB2) indicated that the isolated fungus belonged to the Fusarium solani species complex (FSSC) and was related closely to FSSC22 recovered from Xanthoxylum piperitum in Japan. Pathogenicity tests confirmed that this fungus is the causal agent of grafted twig rot on C. sinensis.

Powdery mildew is a key airborne foliar disease of barley in southeastern and southwestern China. Barley varieties usually partially or wholly lose resistance to the pathogen Blumeria graminis (DC.) f. sp. hordei 3 to 5 years after release due to the frequent acquirements of new virulences in the pathogen population. However, no B. graminis f. sp. hordei virulence detection has been carried out in the recent decade and, thus, no information is available on the present virulence components and major pathotypes in epidemic regions. Twenty-one near-isogenic lines of Pallas were selected to detect B. graminis f. sp. hordei virulence variation, with 97 pathotypes identified from the isolates collected from 2015 to 2019. The virulence complexities ranged from 1 to 12, with 1.5 isolates on average assigned per pathotype, suggesting a natural trait of high pathotype diversity and low virulence complexity in the Chinese B. graminis f. sp. hordei populations. Eleven high-virulence pathotypes were detected in the traditional barley-growing regions in Yunnan and Zhejiang. Six virulent pathotypes to resistance gene mlo-5 were detected only in the two traditional epidemic regions, with a virulence frequency (VF) of 4.8% (7 of 147). Compared with the results from a decade ago, VFs for resistance alleles Mla3, mlo-5, Mla6 + Mla14, Mla7 + Mlk, Mlg + MlCP, and Mla13 + MlRu3 + MlaRu4 increased from 0 to 0.7 to 25.8%. Isolates from Yunnan and Zhejiang had similar virulence profiles, which differed from those identified in Tibet. In addition, genetic diversities differed in the isolate groups collected from Tibet, Yunnan, and Zhejiang.

The genus Alternaria (Pleosporales, Pleosporaceae) comprises saprophytes and pathogens that are widespread around the world. Currently, more than 400 species are recognized within this genus and are classified into 29 sections. In this study, Alternaria strains were isolated from diseased leaves of two cereal crops, rice (Oryza sativa) and maize (Zea mays) in China. These Alternaria spp. were characterized by morphological characterization and phylogenetic analysis using maximum likelihood and Bayesian inference with multiple loci (ITS, GAPDH, RPB2, TEF1, Alt a 1, EndoPG, and OPA10-2). Based on the above analyses, three novel species of Alternaria section Alternaria were introduced, namely A. oryzicolasp. nov., A. poaesp. nov., and A. zeaesp. nov. This study expands the species diversity of Alternaria associated with Poaceae plants in China.