Puccinia praegracilis
| Puccinia praegracilis | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Puccinia praegracilis | ||||||||||||
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Puccinia praegracilis is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is an endoparasite of orchids and the sweet grass Agrostis thurberiana . Symptoms of the infestation by the species are rust spots and pustules on the leaf surfaces of the host plants. It occurs in North America .
features
Macroscopic features
Puccinia praegracilis 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 Puccinia praegracilis grows as with all Puccinia TYPES intercellular and forms Saugfäden that grow into the storage tissue of the host. The cup-shaped aecia of the species have 16–21 × 15–18 µm in size, spherical to broadly ellipsoidal and colorless aeciospores with a wrinkled surface. The yellow uredia of the species grow on the upper side of the leaves of the host plant. Their light yellowish to colorless uredospores are broadly ovate to broadly ellipsoidal, 19–22 × 16–19 µm in size and finely spiky. The parts of the species growing on both or the lower leaf sides are brownish and long covered. The golden to light hazel-brown teliospores of the fungus are two-celled, usually cylindrical to long ovoid and 35–48 × 13–17 µm in size. Their stem is up to 15 µm long.
distribution
The known distribution area of Puccinia praegracilis includes the USA and Canada .
ecology
The host plants of Puccinia praegracilis are for the Haplonts Orchis and habenaria species and Festuca species for the dikaryote . 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 has a development cycle with Telien, Uredien, Spermogonia and Aecien and changes host.
literature
- George Baker Cummins: The Rust Fungi of Cereals, Grasses and Bamboos . Springer, Berlin 1971, ISBN 3-540-05336-0 .