Taxonomy

Taxonomic studies were carried out exclusively with rust fungi in several projects (Projects).

Rust fungi (Pucciniales oder Uredinales) are obligate plant parasitic microfungi with appr. 8.000 known species. Hosts are vascular plants and most species have a narrow host range. Many species have complicated life cycles with several spore states and up to seven morphologically different spore types. The name “rust fungus” traces back to one spore type, the urediniospores and their sori (uredinia) which are often rust coloured. Among rust fungi there are many important pathogens of cultivated plants, such as cereal rusts (e.g. the black stem rust Puccinia graminis). Very special are host-alternating species with two hosts, an aecial and a telial host.  This phenomenon is called heteroecity in rust fungi and is widespread among northern hemisphere species. Tranzschelia pruni-spinosae, e.g., switches from Aemone ranunculoides  (Ranunculaceae) with spore states 0 and I to  Prunus spinosa (Rosaceae) with spore states II, III and IV.

Many species are still not known to science and species delimitation is often difficult. Therefore classical methods (light and scanning electron microscopy) are combined with sequencing  rDNA within the framework of our studies. Both, fresh and herbarium material are used for DNA extraction.

 

Rustologist and his favourite locality
Rustologist and his favourite locality
The rust fungus Coleosporium plumeriae, Hawaii
The rust fungus Coleosporium plumeriae, Hawaii
Host-alternating Puccinia alnetorum deforming its aecial host Clematis
Host-alternating Puccinia alnetorum deforming its aecial host Clematis