Uromyces punctatus
| Uromyces punctatus | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Uromyces punctatus | ||||||||||||
| J. Schröt. |
Uromyces punctatus is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is an endoparasite of milkweed and of the legume genera Astragalus and Oxytropis . Symptoms of the infestation by the species are rust spots and pustules on the leaf surfaces of the host plants. It is spread all over the world.
features
Macroscopic features
Uromyces punctatus can only be recognized with the naked eye by means of 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 punctatus grows as with all Uromyces TYPES intercellular and forms Saugfäden that grow into the storage tissue of the host. Their spermogonia grow systemically on the hosts, just like the aecia of the species. The uredia of the fungus growing on both sides of the host leaves are cinnamon-brown. The golden to light cinnamon-brown uredospores are 22–28 × 19–23 µm in size, spherical to broadly ellipsoidal and spiky. The bilateral parts of the species are chestnut brown, powdery and uncovered. The chestnut-brown teliospores are unicellular, usually spherical to broadly ovate, warty and usually 19–21 × 17–20 µm in size. Their stem is colorless.
distribution
The known distribution area of Uromyces punctatus includes the whole world.
ecology
The host plants of Uromyces punctatus are for the haplonts milkweed ( Euphorbia spp.) And for the dikaryotes various astragalus and oxytropis 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 a heterosexual parasite, it changes 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 .