Puccinia xanthii
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| Schweinitz |
Puccinia xanthii is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is an endoparasite of various pointed burdock . Symptoms of infestation by the species are rust spots on the leaf surfaces of the host plants. The distribution area includes southern Europe and North America.
features
Macroscopic features
Puccinia xanthii can only be recognized with the naked eye by means of the spore beds protruding on the surface of the host. They grow in large nests that appear as reddish to brown spots on the leaf and stem surfaces. Often these spots flow into one another and then form crusts up to 4 cm long, and the affected tissue also swells on the stems.
Microscopic features
The mycelium of Puccinia xanthii grows as with all Puccinia TYPES intercellular and forms Saugfäden that grow into the storage tissue of the host. The parts of the species are rounded or oblong. They are surrounded by short, dark brown paraphyses. The teleutospores are rarely one, mostly two-celled, elongated to club-shaped and 36–52 × 16–31 µm in size; their stem is short and light brownish.
distribution
The species area of Puccinia xanthii covers a Holarctic distribution area with southern Europe and North America . Presumably originally from North America, it was introduced to numerous countries such as South Africa and Australia.
ecology
The host plants of Puccinia xanthii are various pointed burdock ( Xanthium spp.). Other hosts are the sunflower and ragweed . 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 of which only parts are known.
application
Puccinia xanthii is used in Australia for biological pest control against Xanthium occidentale . However , the species does not seem to be suitable for combating the mugwort-leaved ragweed .
Systematics and taxonomy
The species is closely related to several very similar rusts, all of which are found in South and North America on different daisy family and differ only in their host. It is therefore suggested to classify all these species con-specifically with Puccinia xanthii . Puccinia xanthii is therefore a morpho species and the remaining species are classified as varieties. These species include Puccinia melampodii , Puccinia cnici-oleracei, and Puccinia semota .
literature
- Ernst Gäumann: The rust fungi of Central Europe. With special consideration of Switzerland (= contributions to the cryptogam flora of Switzerland . Volume XII ). Commission publisher Buchdruckerei Büchler & Co, Bern 1959.
Individual evidence
- ^ G. Gurr, SD Wratten: Biological Control: Measures of Success. Springer, 2010, p. 332.
- ↑ L. Morin, BA Auld, JF Brown: Host range of Puccinia xanthii and postpenetration development on Xanthium occidentale . In: Canadian Journal of Botany. 71, 1993, pp. 959-965.
- ↑ L. Morin, JF Brown, BA Auld: Teliospore germination, basidiospore formation and the infection process of Puccinia xanthii on Xanthium occidentale. In: Mycological Research. 96, 1992, pp. 661-669.
- ^ G. Gurr, SD Wratten: Biological Control: Measures of Success. Springer, 2010, p. 332.
- ^ L. Kiss: Is Puccinia xanthii a suitable biological control agent of Ambrosia artemisiifolia ? In: Biocontrol Science and Technology. 17, 2007, pp. 535-539.
- ^ Marion K. Seier, Louise Morín, Marlien van der Merwe, Harry C. Evans, Ángel Romero: Are the microcyclic rust species Puccinia melampodii and Puccinia xanthii conspecific? In: Mycological research. 113, 2009, pp. 1271-1282. doi: 10.1016 / j.mycres.2009.08.009 .
- ↑ JF Hennen, MB Figueiredo, AA de Carvalho Jr, PG Hennen: Catalog of the Species of Plant Rust Fungi (Uredinales) of Brazil. 2005. (online)