Alternaria species are commonly found as saprophytes, endophytes and plant pathogens. During a survey of small-spored Alternaria in China, two new species were discovered from Cucurbitaceae plants collected in Hubei and Sichuan provinces. This study identified two new species of Alternaria using seven genes (ITS, GAPDH, TEF1, RPB2, Alt a 1, EndoPG, and OPA10-2) for phylogenetic analyses and morphological characteristics. The two new species A. jingzhouensis and A. momordicae were described and illustrated. Alternaria jingzhouensissp. nov., associated with Citrullus lanatus, is characterized by producing muriform, ellipsoidal, flask-shaped, rostrate, and beaked conidia. It differs from A. koreana, A. ovoidea, and A. baoshanensis by bearing conidia in a simple conidiogenous locus with occasionally longer beaks in a chain, and from A. momordicaesp. nov. by having shorter beaks. Alternaria momordicaesp. nov. from Momordica charantia was distinct from A. koreana, A. ovoidea, and A. baoshanensis by producing muriform, long ellipsoid or ovoid to obclavate, sometimes inverted club-shaped conidia on a single conidiogenous locus with a wider body and longer beak in a chain, and distinct from A. jingzhouensissp. nov. by a longer beak conidia. These two species were clearly distinguished from other species in the section Alternaria based on DNA based phylogeny and morphological characteristics. The morphological features were discussed and compared to relevant species in the present paper.

Small-spored Alternaria species have been frequently isolated from diseased leaves of Solanum plants. To clarify the diversity of small-spored Alternaria species, a total of 118 strains were obtained from leaf samples of S. tuberosum and S. lycopersicum in six provinces of China during 2022–2023. Based on morphological characterization and multi-locus phylogenetic analysis of the internal transcribed spacer of the 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), endopolygalacturonase gene (EndoPG) and an anonymous gene region (OPA10-2), seven species were determined, including four novel species and three known species (A. alternata, A. gossypina and A. arborescens). The novel species were described and illustrated as A. longxiensis sp. nov., A. lijiangensis sp. nov., A. lycopersici sp. nov. and A. solanicola sp. nov.. In addition, the pathogenicity of the seven species was evaluated on potato leaves. The species exhibited various aggressiveness, which could help in disease management.

Sunflower (Helianthus annuus L.) is a widely cultivated, fast-growing crop known for its seeds and oil, with substantial ecological and economic importance globally. However, it faces challenges from leaf diseases caused by Alternaria species, which threaten its yield. Three small-spored Alternaria species were isolated from leaf spot and blight symptoms on sunflower in Myanmar. All the species were determined based on morphological characterization and a multi-locus phylogenetic assessment of seven genes, including the internal transcribed spacer of rDNA region (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), RNA polymerase second largest subunit (RPB2), translation elongation factor 1-α (TEF1), Alternaria major allergen gene (Alt a 1), endopolygalacturonase gene (EndoPG), and an anonymous gene region (OPA10-2). The results introduced two new Alternaria species, A. myanmarensissp. nov. and A. yamethinensissp. nov., and a known species of A. burnsii, firstly reported from sunflower.

Foshou yam (Dioscorea esculenta) is a tuber food crop in China. It is a rare species of the yam family and known for its high nutritional value. From 2019 to 2021, tuber rot was observed in Foshou yam in Wuxue, Hubei Province, China. Fungal strains were isolated from diseased tubers, and ten representative strains were identified based on microscopical characterization and multi-locus phylogenetic analysis. A total of five different species were identified, including Curvularia geniculata, Curvularia muehlenbeckiae, Fusarium commune, Penicillium oxalicum, and Penicillium sclerotigenum. Pathogenicity test revealed that these fungi are the pathogens of tuber rot in Foshou yam. Among them, P. oxalicum exhibited the strongest pathogenicity. To our knowledge, this is the first report of tuber rot in D. esculenta caused by these five species worldwide. This study provides important information for the future management of tuber rot in Foshou yam.

Tomato (Solanum lycopersicum) originating from Western South America is widely cultivated as a commercial crop around the world. It is rich in a series of nutrition such as vitamin C, phytochemical...

Alternaria is a widely distributed fungal genus as saprophytes, endophytes, and pathogens. An Alternaria species was isolated from the leaf spot of Fagopyrum esculentum in Banxi Town, Youyang County, Chongqing municipality, China. The obtained strains were determined based on morphological characteristics and multi-locus phylogenetic analyses including the internal transcribed spacer (ITS) of the rDNA region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), translation elongation factor 1-alpha (TEF1), RNA polymerase second largest subunit (RPB2), a major Alternaria allergen (Alt a 1), endopolygalacturonase (EndoPG) and an anonymous region gene (OPA10-2) gene sequences. The results indicate that the present species is a novel species, which is described and illustrated as Alternaria youyangensis sp. nov. in this study.