Puccinia punctiformis
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Puccinia punctiformis |
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| ( F. Strauss ) Röhl. |
Puccinia punctiformis is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is an endoparasite of the field thistle . 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 punctiformis 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 punctiformis 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 underside of the host leaves. The aecia of the species, mostly growing on the top of the leaves, are dark cinnamon-brown and stand around the spermogonia. Their cinnamon-brown aeciospores are 26–30 × 23–28 µm in size, mostly spherical and spiky. The uredia of the fungus, mostly growing underneath the leaves, are cinnamon brown. The cinnamon-brown uredospores are 26–30 × 23–28 µm in size, mostly spherical and spiky. The parts of the species, which predominantly grow on the underside of the leaves, are chocolate brown, powdery and uncovered. The deep golden to clear maroon teliospores are two-celled, usually broadly ellipsoidal to ellipsoidal, finely warty and mostly 32–38 × 20–24 µm in size. Their stem is colorless.
distribution
The known distribution area of Puccinia punctiformis covers large parts of the world due to the spreading of the host.
ecology
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The host plant of Puccinia punctiformis is the field thistle ( Cirsium arvense ). 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 . The transmission is presumably carried out by insects sucking on the shoot, although some studies cast doubt on this. Puccinia punctiformis produces insect attractants like phenylacetaldehyde , 2-phenylethanol , and benzaldehyde , which imitate the scent of flowers and thus attract insects. However, so-called pseudo-flowers as in Puccinia monoica or Uromyces pisi do not develop .
meaning
Puccinia punctiformis is used in North America and New Zealand for biological pest control of the field thistle, as it often infects the plant systemically and kills it before the flowers form. However, the success was only moderate, since the teliospores were only heterogeneously distributed, which led to a low incidence of infected plants.
literature
- George Baker Cummins : Rust Fungi on Legumes and Composites in North America . University of Arizona Press, Tucson 1978, ISBN 0-8165-0653-1 .
Individual evidence
- ^ H. Wandeler, W. Nentwig, S. Bacher: Establishing Systemic Rust Infections in "Cirsium arvense" in the Field. In: Biocontrol Science and Technology. 18 2008, pp. 209-214.
- ^ MG Cripps, GR Edwards, NW Waipara, GW Bourdôt, DJ Saville, SV Fowler: Does transmission of the rust pathogen, "Puccinia punctiformis", require stem mining vectors? In: Biocontrol Science and Technology. 19 2009, pp. 447-454.
- ↑ Connick W Jr, French R (1991) Volatiles emitted during the sexual stage of the Canada thistle rust fungus and by thistle flowers. Journal of Agricultural and Food Chemistry, 39, 185-188. doi : 10.1021 / jf00001a037
- ↑ Robert A. Raguso and Barbara A. Roy (1998) Floral scent production by Puccinia rust fungi that mimic flowers. Molecular Ecology 7, 1127-1136.
- ↑ RC French, AR Light Field: Induction of Systemic Infection Aecial in Canada Thistle ( Cirsium arvense ) by Teliospores of "Puccinia punctiformis" . In: Phytopathology. 80 1990, pp. 872-877.
- ↑ RF Thomas, TJ Tworkoski, RC French, GR Leather: "Puccinia punctiformis" Affects Growth and Reproduction of Canada thistle ( Cirsium arvense ). In: Weed Technology. 8 1994, pp. 488-493.
- ↑ AM Demers, DK Berner, PA Backman: Enhancing incidence of “Puccinia punctiformis”, through mowing, to improve management of Canada thistle (“Cirsium arvense”). In: Biological Control. 39 2006, pp. 481-488.
