telium
{{Short description|Structure produced by rust fungi as part of the reproductive cycle}}
File:Gymnosporangium telia macro IMGP0418.jpg
Telium, plural telia, are structures produced by rust fungi as part of the reproductive cycle.Brand g, Brand R & Shattock R,.Sorting out Gymnosporangium species - the aecial stage, October 2006, Field Mycology Volume 7(4) They are typically yellow or orange drying to brown or black and are exclusively a mechanism for the release of teliospores which are released by wind or water to infect the alternate host in the rust life-cycle. The telial stage provides an overwintering strategy in the life cycle of a parasitic heteroecious fungus by producing teliospores; this occurs on cedar trees. A primary aecial stage is spent parasitizing a separate host plant which is a precursor in the life cycle of heteroecious fungi. Teliospores are released from the telia in the spring. The spores can spread many kilometers through the air, however most are spread near the host plant.Brand, A.W. et al. 2004. The Other Half: The telial stage of the rust fungus Gymnosporangium confusum. Field Mycology. Vol 5:14-16
Host plants
There are a number of plants that can be infected by the telial stage. Therefore, the telial stage is considered a pathogen to those plants. A few specific plant pathogenic species are listed here with their hosts.
- Puccinia graminis or known commonly as black stem rust. It infects many different cereal crops.
- Gymnosporangium juniperi-virginianae. It infects the eastern red cedar.Volk, T.J. Tom Volk's Fungus of the Month for May 1999. University of Wisconsin La Crosse. http://botit.botany.wisc.edu/toms_fungi/may99.html, December 5, 2010 This is shown to the right.
- Gymnosporangium sabinae. It infects pear trees.
File:Stem rust close up.jpg|Puccinia graminis on wheat.
File:Gymnosporangium sabinae fg05.JPG|Gymnosporangium sabinae on a pear tree leaf.
Spore stages
The life cycle of rust fungi can have up to five different spore stages and can get quite complex.Schumann, G.L. et al. 2010. Essential Plant Pathology. American Phytopathological Society. Second Edition. St. Paul. pp. 43–44 These stages are:
- Stage 0: Pycniospores
- Stage I: Aeciospores
- Stage II: Urediniospores
- Stage III: Teliospores
- Stage IV: Basidiospores
File:Puccina graminis lifecycle.gif|Life Cycle of Puccina graminis