Exobasidium caucasicum
| Exobasidium caucasicum | ||||||||||||
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| Scientific name | ||||||||||||
| Exobasidium caucasicum | ||||||||||||
| Voronikhin |
Exobasidium caucasicum is a fungus - kind of the family of Nacktbasidienverwandten (Exobasidiaceae) from the subdivision Ustilaginomycotina . It is an endoparasite of Rhododendron aureum . Symptoms of infection by the fungus are chlorosis and deformation of the leaves of the host plants. The mushroom species is common in large parts of Eurasia .
features
Macroscopic features
Exobasidium caucasicum is initially invisible to the naked eye. Symptoms of the infestation are a reddish chlorosis and rib-like deformations of the leaves, which are also greatly enlarged.
Microscopic features
As with all naked basidia , the mycelium of Exobasidium caucasicum grows intercellularly and forms suction threads that grow into the host's storage tissue. The two- to four-pore, 13–35 × 5–12 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 11–19 × 3–6 µm in size. At first they are unsepted, when ripe they have one or two septa . The conidia are hyaline, spindle-shaped to teardrop-shaped and 3–7 × 1–2 μm in size.
distribution
The known distribution area of Exobasidum caucasicum extends from the Caucasus to Japan .
ecology
The host plant of Exobasidium caucasicum is Rhododendron aureum . 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 .