Soybean (Glycine max L.) seeds showing serious symptoms from rotted pods were collected from fields during the harvesting period (July to August of 2020) in Taihu Farm, Jingzhou City, Hubei Province, China. Fusarium strains were frequently encountered during fungal isolation. According to the morphology and pre-pathogenicity tests, six strains showing variable effects on the seeds were selected for identification based on morphology and multi-locus phylogenetic analysis of the internal transcribed spacer region of the rDNA (ITS), translation elongation factor (EF-1α), calmodulin (CAM), beta-tubulin (TUB), and partial RNA polymerase second largest subunit (RPB2), and to evaluate the pathogenic abilities on seed, root, and pod. The results indicated that the strains contained two species (Fusarium fujikuroi and F. proliferatum) in the Fusarium fujikuroi species complex (FFSC) and two species (F. luffae and F. sulawense) from the Fusarium incarnatum-equiseti species complex (FIESC). The two species of FFSC were more aggressive than those of FIESC on soybean seed, root, and pod. Among the strains, F. proliferatum YZU 201408 exhibited the most pathogenicity on all tests with 72.2–90% disease severity. Keywords: Fusarium, Glycine max L., Morphology, Pathogenicity, Phylogenetic analysis

Plants of the Iris genus have been widely cultivated because of their medicinal, ornamental, and economic values. It commonly suffers from Alternaria leaf spot or blight disease leading to considerable losses for their commercial values. During an investigation of 14 provinces or municipalities of China from 2014 to 2022, a total of 122 Alternaria strains in section Alternaria were obtained from diseased leaves of Iris spp.. Among them, 12 representative strains were selected and identified based on morphological characterization and multi-locus phylogenetic analysis, which encompassed the internal transcribed spacer of rDNA region (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), translation elongation factor 1 alpha (TEF1), RNA polymerase second largest subunit (RPB2), Alternaria major allergen gene (Alt a 1), an anonymous gene region (OPA10-2), and endopolygalacturonase gene (EndoPG). The strains comprised two known species of A. alternata and A. iridicola, and two new species of A. setosae and A. tectorum, which were described and illustrated here. Their pathogenicity evaluated on Iris setosa indicated that all the strains could induce typical Alternaria leaf spot or blight symptoms. The results showed that the virulence was variable among those four species, from which A. tectorum sp. nov. was the most virulent one, followed by A. setosae sp. nov., A. iridicola and A. alternata.

Alternaria is a ubiquitous fungal genus including saprobic, endophytic, and pathogenic species associated with a wide variety of substrates. It has been separated into 29 sections and seven monotypic lineages based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing the majority of large-spored Alternaria species, most of which are important plant pathogens. Since 2015, of the investigations for large-spored Alternaria species in China, 13 species were found associated with Compositae plants based on morphological comparisons and phylogenetic analyses. There were eight known species and five new species (A. anhuiensis sp. nov., A. coreopsidis sp. nov., A. nanningensis sp. nov., A. neimengguensis sp. nov., and A. sulphureus sp. nov.) distributed in the four sections of Helianthiinficientes, Porri, Sonchi, and Teretispora, and one monotypic lineage (A. argyranthemi). The multi-locus sequence analyses encompassing the internal transcribed spacer region of rDNA (ITS), glyceraldehydes-3-phosphate dehydrogenase (GAPDH), Alternaria major allergen gene (Alt a 1), translation elongation factor 1-alpha (TEF1), and RNA polymerase second largest subunit (RPB2), revealed that the new species fell into sect. Porri. Morphologically, the new species were illustrated and compared with other relevant large-spored Alternaria species in the study. Furthermore, A. calendulae, A. leucanthemi, and A. tagetica were firstly detected in Brachyactis ciliate, Carthamus tinctorius, and Calendula officinalis in China, respectively.

Alternaria leaf spot is a common disease on various plants worldwide. In this study, an Alternaria species, A. hydrangeae causing leaf spot on Cucumis sativus (cucumber) and Ipomoea purpurea in China was identified based on morphology and multi-locus analysis of the partial ITS, GAPDH, Alt a 1, TEF1, and RPB2 gene regions. The pathogenicity of the present isolates and a representative isolate of A. hydrangeae were assessed on living leaves of C. sativus, I. purpurea and Hydrangea paniculata. Similar symptoms were observed on every plant inoculated with the isolates. The same fungus was re-isolated from inoculated leaves fulfilling Koch's postulates. Morphology of the original and reisolated isolates showed characteristics similar to A. hydrangeae with some variations.Multi-locus analysis indicated that the present isolate fell into A. hydrangeae clade.This study is the first report of A. hydrangeae as an agent of Alternaria leaf spot in C. sativus and I. purpurea in China, which extends the host range of the fungus.