Search Results (3)

Fusarium species are agriculturally important fungi with a broad host range and can be found as endophytic, pathogenic, or opportunistic parasites in many crop plants. This study aimed to identify Fusarium species in bare-rooted, dormant plants in Turkish grapevine nurseries using molecular identification methods and assess their pathogenicity. Asymptomatic dormant plants were sampled from grapevine nurseries (43) in different regions of the country, and fungi were isolated from plant roots and internal basal tissues. The Fusarium strains were identified by performing gene sequencing (TEF1-α, RPB2) and phylogenetic analyses. Pathogenicity tests were carried out by inoculating mycelial agar pieces of strains onto the stem or conidial suspensions into the rhizosphere of vines (1103 Paulsen rootstock). Laboratory tests revealed that Fusarium species were highly prevalent in Turkish grapevine nurseries (41 out of 43). Gene sequencing and phylogenetic analyses unraveled that 12 Fusarium species (F. annulatum, F. brachygibbosum, F. clavum, F. curvatum, F. falciforme, F. fredkrugeri, F. glycines, F. nanum, F. nematophilum, F. nirenbergiae, F. solani, and Fusarium spp.) existed in the ready-to-sale plants. Some of these species (F. annulatum, F. curvatum and F. nirenbergiae) consistently caused wood necrosis of seedling stems, rotting of the basal zone and roots, and reduced root biomass. Although the other nine species also caused some root rot and root reduction, their virulence was not as severe as the pathogenic ones, and they were considered opportunistic parasites or endophytic species. This study suggests that Fusarium species might play an important role in root-basal rot, wood canker symptoms, and young vine decline in Turkish grapevine nurseries and that these species need to be considered for healthy seedling production. Full article

Sweet cherry is an important fruit crop in China with a high economic value. From 2019 to 2020, a leaf spot disease was reported, with purplish-brown circular lesions in three cultivating regions in China. Twenty-four Fusarium isolates were obtained from diseased samples and were identified based on morphological characteristics and multi-locus phylogenetic analyses. Seven species, including F. luffae (7 isolates), F. lateritium (6 isolates), F. compactum (5 isolates), F. nygamai (2 isolates), F. citri (2 isolates), F. ipomoeae (1 isolate) and F. curvatum (1 isolate) were identified. The pathogenicity test showed that analyzed strains of all species could produce lesions on detached cherry leaves. Therefore, Fusarium was proved to be a pathogen of cherry leaf spots in China. This is the first report of F. luffae, F. compactum, F. nygamai, F. citri, F. ipomoeae and F. curvatum on sweet cherry in China. Full article

A rare plant species of the Orchidaceae family, Dendrobium officinale is considered among the top ten Chinese medicinal herbs for its polysaccharide. Since 2021, when the dieback disease of D. officinale was first reported in Yueqing City, Zhejiang Province, China, Fusarium isolates (number = 152) were obtained from 70 plants in commercial greenhouses. The disease incidence ranged from 40% to 60% in the surveyed areas. Multilocus sequence analysis (MLSA) coupled with morphological characterization revealed that the collected isolates belonged to five species (sp.), viz., Fusarium concentricum, F. fujikuroi, F. nirenbergiae, F. curvatum, and F. stilboides, with isolation frequencies of 34.6%, 22.3%, 18.4%, 13.8%, and 10.5%, respectively. Notably, at least two Fusarium species were simultaneously isolated and identified from the infected plants. Finally, the pathogenicity test results demonstrated that such species were responsible for the dieback disease of D. officinale. However, F. concentricum and F. fujikuroi were more invasive compared to the other species in this study. To the best of the authors’ knowledge, this study was the first report of F. concentricum, F. curvatum, F. fujikuroi, F. nirenbergiae, and F. stilboides causing the dieback disease of D. officinale in China and worldwide. This work provides valuable data about the diversity and pathogenicity of Fusarium populations, which will help in formulating effective strategies and policies for better control of the dieback disease. Full article