Exobasidium poasanum
| Exobasidium poasanum | ||||||||||||
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| Scientific name | ||||||||||||
| Exobasidium poasanum | ||||||||||||
| Goméz & Kisimova-Horovitz |
Exobasidium poasanum is a mushroom art family of Nacktbasidienverwandten (Exobasidiaceae) from the order Ustilaginomycotina . It lives as an endoparasite on Cavendishia bracteata . Symptoms of infestation by the fungus are reddish leaf galls and spindle-shaped, reddish hypertrophy sites on the stems of the host plant. The species isnativeto the area of Costa Rica .
features
Macroscopic features
Exobasidium poasanum is initially invisible to the naked eye. Symptoms of the infestation are very large, pinkish-red galls on the leaves, accompanied by hypertrophic , spindle-shaped spots on the stems. In the late stages of the infestation, the mycelium emerges as a white felt carpet on the underside of the leaves.
Microscopic features
As in all naked basidia , the mycelium of Exobasidium poasanum grows intercellularly and forms suction threads that grow into the host's storage tissue. The fungus has a monomitic hypha structure made up of purely generative hyphae without buckles . The two- to four-, rarely six-pore, 16–24.2 × 5–7 µm large basidia are simply septate at the base. They grow directly from the host epidermis or from stomata . The elliptical spores are hyaline , thin-walled and 12.5–20.5 × 3–4 µm in size. When ripe they have two septa . The conidia are milky-hyaline, 9–15 × 1.5–1.8 µm in size and cylindrical.
distribution
The known distribution area of Exobasidum poasanum only includes the type locality on the Poás in Costa Rica .
ecology
The host plant of Exobasidium poasanum is Cavendishia bracteata . The fungus feeds on the nutrients present in the storage tissue of the plants, its basidia later break through the leaf surface and release spores. After they have fallen on a suitable substrate, these germinate into germ tubes and conidia, from which new mycelium then develops.
swell
- Luis D. Gómez, Liuba Kisimova-Horovitz: Basidiomicetes de Costa Rica. Nuevas especies de Exobasidium (Exobasidiaceae) y registros de Cryptobasidiales . In: Revista de Biología Tropical . 46, No. 4, 1998, pp. 1081-1093.