Alternaria japonica | |
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Scientific classification
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Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Dothideomycetes |
Order: | Pleosporales |
Family: | Pleosporaceae |
Genus: | Alternaria |
Species: | A. japonica
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Binomial name | |
Alternaria japonica Yoshii, (1941)
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Synonyms | |
Alternaria mattiolae Neerg., (1945) |
Alternaria japonica is a fungal plant pathogen. [1] It is a cause of black spot disease in cruciferous plants. [1] It is not a major source of crop loss, but is considered dangerous for plants during the seedling stage. [1]
Alternaria japonica affects its hosts in all stages of life. [1] Infection causes a black or grey sunken lesion with a characteristic yellow border. [1] [2] On the leaves of some plants, infection can cause dark, water-soaked spots. [3] The lesions can be observed anywhere on the plant. [1] In seedlings, fungal lesions on the stem are a cause of damping-off. [4] Infected seeds appear black or grey. [1]
The fungus can first be detected by visually observing symptoms on infected plants. When cultured on potato carrot agar, it will form a grey or brownish, cobweb-like mycelium. [1] Upon microscopic inspection, A. japonica has septate, branched hyphae and appears colorless to greenish grey. [1] Chlamydospores are multicellular with thick, rough walls. [1] Conidia are solitary and beakless. [1] Sequencing of the ribosomal DNA is commonly used for positive identification because the symptoms and microscopic appearance can resemble those of related species. [1] [2] [3] [4] [5]
Transmission of A. japonica occur from infected seeds and plant debris or conidia produced by the fungus in wet conditions. [1] The major hosts of this organism are species in Brassicaceae such as cauliflower, turnip, and cabbage. [1] [2] Whether it can infect species outside of this family is unclear. [1] This fungus is not thought to be a cause of disease in humans, unlike other members of Alternaria. [1] Occurrences of black spot caused by A. japonica have been reported worldwide. [1] [2] [3] [4]
Once A. japonica has been established in an area, it can be difficult to eradicate because it can survive in a dormant state in the soil for years. [1] Prevention of the spread of A. japonica by controlling the transportation of infected plant materials and seeds is crucial. [1] Disinfection of seeds is an effective preventative measure. [6] A variety of chemical fungicides can be used to protect seedlings. [1] Integrated pest management practices such as crop rotation with non-cruciferous plants can be beneficial for farmers dealing with this fungus. [1]