Exobasidium rhododendri-nivalis
| Exobasidium rhododendri-nivalis | ||||||||||||
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| Exobasidium rhododendri-nivalis | ||||||||||||
| Li & Guo |
Exobasidium rhododendri-nivalis is a smut fungus species from the family of the naked basidia relatives (Exobasidiaceae). It lives as an endoparasite on Rhododendron nivalis . Symptoms of infection by the fungus are red galls on the top of leaves, stems, and sprouts that are laterovergrownby white mycelium . So far the species has only been found in Yunnan and Sichuan .
features
Macroscopic features
Exobasidium rhododendri-nivalis is initially invisible to the naked eye. The initial symptoms of the infestation can be seen in the form of red galls 1–4 mm in size. Both the upper and lower sides of the leaves goggle. Over time, the galls turn yellow, then brown. Later, white mycelium sprouts from the galls and overgrows them.
Microscopic features
The mycelium of Exobasidium rhododendri-nivalis grows intercellularly and forms suction threads that grow into the host's storage tissue. The three- to five-pore, 7–18 × 4–8 µm large basidia are long, unseptate and club-like to cylindrical. The cylindrical spores are hyaline , 10–13 × 2.5–3 µm in size. At first they are unsepted, when ripe they have a septum .
distribution
Exobasidum rhododendri-nivalis was described from China. The localities are also limited to Yunnan and Sichuan and lie between 4300 and 4650 m.
ecology
Exobasidium rhododendri-nivalis attacks Rhododendron nivalis . 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 in germ tubes, from which new mycelium then develops.
swell
- ZY Li, L. Guo: Two New Species and a New Chinese Record of Exobasidium (Exobasidiales) from China. In: Mycotaxon 105, 2008. pp. 331-336.