Puccinia discreta
| Puccinia discreta | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Puccinia discreta | ||||||||||||
| H: S. Jackson & Holway |
Puccinia discreta is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is an endoparasite of the daisy family Vernonia stellaris . Symptoms of the infestation by the species are rust spots and pustules on the leaf surfaces of the host plants. It is common in South and Central America .
features
Macroscopic features
Puccinia discreta can only be recognized with the naked eye by the spore beds protruding on the surface of the host. They grow in nests that appear as yellowish to brown spots and pustules on the leaf surfaces.
Microscopic features
The mycelium of Puccinia discreta grows as with all Puccinia TYPES intercellular and forms Saugfäden that grow into the storage tissue of the host. Their spermogonia grow on the upper side in small groups on the surfaces of the host leaves. The aecia of the species are unknown. The fungus lacks uredia . The parts of the species growing on the top of the leaves are cinnamon brown, densely grouped, powdery and uncovered. The golden-brown teliospores are two-celled, usually ellipsoid, waisted, finely wrinkled and mostly 25–43 × 21–25 µm in size. Their stem is colorless.
distribution
The known distribution area of Puccinia discreta extends from South America to Mexico .
ecology
The host plants of Puccinia discreta are Vernonia stellaris and Vernonia deppeana . The fungus feeds on the nutrients present in the storage tissue of the plants, its spore beds later break through the leaf surface and release spores. The species goes through a microcyclic development cycle with spermogonia, aecia and telia. As a self-sufficient parasite, it does not change host .
literature
- George Baker Cummins : Rust Fungi on Legumes and Composites in North America . University of Arizona Press, Tucson 1978, ISBN 0-8165-0653-1 .