Exobasidium shiraianum
| Exobasidium shiraianum | ||||||||||||
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| Scientific name | ||||||||||||
| Exobasidium shiraianum | ||||||||||||
| Hennings |
Exobasidium shiraianum is a mushroom art family of Nacktbasidienverwandten (Exobasidiaceae) from the order Ustilaginomycotina . It is an endoparasite of various rhododendrons . Symptoms of the infestation by the fungus are the bleaching of the leaves and sometimes the emergence of the mycelium on the underside of the leaves of the host plants. The mushroom species is common in Japan .
features
Macroscopic features
Exobasidium shiraianum is initially invisible to the naked eye. Symptoms of the infestation are chlorosis of the leaves and sometimes the emergence of powdery mycelium on the undersides of young leaves.
Microscopic features
As with all naked basidia , the mycelium of Exobasidium shiraianum grows intercellularly and forms suction threads that grow into the host's storage tissue. The two- to three-pore, 5–30 × 5–9 µm large basidia are long, unseptate and cylindrical to club-shaped. They grow directly from the host epidermis or from stomata . The elliptical to egg-shaped spores are hyaline and 11–21 × 5–8 µm in size. At first they are unsepted, when ripe they have one to three, rarely four septa . The conidia are hyaline, almost spindle-shaped to bacillus and 2–10 × 1–2 μm in size.
distribution
The known distribution area of Exobasidum shiraianum extends over all of Japan .
ecology
The host plants of Exobasidium shiraianum are various rhododendrons ( Rhododendron spp.). 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
- Hideyuki Nagao, Toyozo Sato, Makoto Kakishima: Three species of Exobasidium causing Exobasidium leaf blight on subgenus Hymenanthes, Rhododendron spp., In Japan . In: Mycoscience . 45, No. 2, 2004, ISSN 1340-3540 , pp. 85-95. doi : 10.1007 / s10267-003-0162-8 .