Uromices-pisi-sativi_5

Description:

Uromyces pisi-sativi, syn.: Uromyces pisi, Puccinia pisiPea RustSlo.: grahova rja Dat.: April 25. 2011Lat.: 46.33889 Long.: 13.53691Code: Bot_509/2011_DSC7362 Habitat: Relatively dry sandy grassland, grazed by sheep, shallow soil, almost flat terrain, full sun, exposed to direct rain, average precipitations ~ 3.000 mm/year, average temperature 8-10 deg C, elevation 540 m (1.800 feet), alpine phytogeographical region.Substratum: Euphorbia cyparissias plantPlace: above the road to Pluna village, Bovec basin, East Julian Alps, Posoje, Slovenia EC Comments: This rust fungus modifies its host plant Euphorbia cyparissias. Infected plants usually don't produce fertile flowers and are much more slender and taller than normal. But they form a kind of pseudo-flowers, a rosette of leaves at the top of stalks, resembling true lowers. Fungus produces nectar similar to nectar of healthy plants. It attracts ants and other insects, both on healthy and infected plants. For over 100 years this host-pathogen pair has been subject to much speculation concerning the function of nectar-producing spermatia. Today, it is generally assumed that they are produced to attract insects for fungal fertilization (more in Ref.: 4.).Urediniospores finely warty, dimensions: 24.0 (SD = 1.2) x 21.5 (SD = 0.7) micr., Q = 1.12 (SD = 0.07), n = 25. Ref.: (1) www.agroatlas.ru/en/content/diseases/Fabacee/Fabacee_Urom...(2) www.ncbi.nlm.nih.gov/pubmed/10636829 (3) www.uni-graz.at/walter.obermayer/plants-of-styria/images/...(4) www.amjbot.org/cgi/content/full/87/1/48#F1(5) e-collection.library.ethz.ch/eserv/eth:23187/eth-23187-01...