Sunflower rust
| Sunflower rust | ||||||||||||
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Sunflower rust ( Puccinia helianthi ) on the underside of a sunflower leaf |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Puccinia helianthi | ||||||||||||
| Schweinitz |
The sunflower rust ( Puccinia helianthi ) is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is a endoparasite the daisy family genus Helianthus , Iva and Heliopsis . 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
Puccinia helianthi 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 helianthi grows as with all Puccinia TYPES intercellular and forms Saugfäden that grow into the storage tissue of the host. Their spermogonia grow predominantly on the upper side of the host leaves. The aecia of the species growing underneath the leaves are short-cylindrical and are in groups. They have spherical to ellipsoidal, colorless aeciospores with a warty surface, 20–25 × 16–21 µm in size. The uredia of the fungus, mostly growing underneath the leaves, are cinnamon brown. Their uredospores, which are also cinnamon-brown, are 26–33 × 18–22 µm in size, ovate to long ellipsoid and spiky. The parts of the species growing on both sides or mainly underneath the leaves are black-brown, compact and uncovered early. The golden to light chestnut brown teliospores are two-celled, usually long ovoid to long ellipsoid and 38–60 × 21–30 µm in size. Their stem is colorless and up to 170 µm long.
distribution
The known distribution area of Puccinia helianthi includes the entire world.
ecology
The host plants of Puccinia helianthi are various Helianthus , Iva and Heliopsis 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, but does not change host ( autocial ).
literature
- George Baker Cummins : Rust Fungi on Legumes and Composites in North America . University of Arizona Press, Tucson 1978, ISBN 0-8165-0653-1 .
