Uromyces cucullatus
| Uromyces cucullatus | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Uromyces cucullatus | ||||||||||||
| Syd. & P. Syd. |
Uromyces cucullatus is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is an endoparasite of the sunflower genera Zexmenia , Perymenium , Wedelia and Baltimora . Symptoms of the infestation by the species are rust spots and pustules on the leaf surfaces of the host plants. It is common in Central America .
features
Macroscopic features
Uromyces cucullatus can only be recognized by the naked eye from 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 Uromyces cucullatus grows as with all Uromyces TYPES intercellular and forms Saugfäden that grow into the storage tissue of the host. Their spermogonia grow on the upper side of the surface of the host leaves. The aecia of the species growing underneath the leaves are whitish and cylindrical. Their hyaline aeciospores are 22–26 × 19–24 µm in size, spherical to broadly ellipsoidal and warty. The uredia of the fungus growing on both sides or mainly underneath the leaves are light cinnamon brown. The cinnamon - brown uredospores of the species are 18–21 × 18–22 µm in size, triangular, ovate to spherical and spiky. The parts of the species that grow on both or mainly underside of the leaves are black-brown, powdery and uncovered. The golden to deep chestnut-brown teliospores are unicellular, usually spherical to almost spherical, warty and mostly 28–33 × 24–28 µm in size. Their stem is usually colorless and up to 120 µm long.
distribution
The known distribution area of Uromyces cucullatus extends from central Mexico to Panama .
ecology
The host plants of Uromyces cucullatus are Baltimora recta , Wedelia acapulcensis and various Zexmenia and Perymenium species. 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 macrocyclical development cycle with Spermogonia, Aecien, Telien and Uredien. As an auto-ecologic 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 .