Rust (fungus) Rust (fungus) Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales (previously also known as Uredinales). An estimated 168 rust genera and approximately 7,000 species, more than half of which belong to the genus "Puccinia", are currently accepted. Rust fungi are highly specialized plant pathogens with several unique features. Taken as a group, rust fungi are diverse and affect many kinds of plants. However, each species has a very narrow range of hosts and cannot be transmitted to non-host plants. In addition, most rust fungi cannot be grown easily in pure culture. A single species of rust
Wheat yellow rust In 1953, Hylander et al. (1953) revived the name P. striiformis. "Yellow rust" takes its name from the appearance of yellow-colored stripes produced parallel along the venations of each leaf blade. These yellow stripes are actually characteristic of uredinia that produce yellow colored urediniospores. Primary hosts of yellow rust are "Triticum aestivum" (bread wheat), "Triticum turgidum" (durum wheat), triticale, and a few "Hordeum vulgare" (barley) cultivars. The alternate host was discovered by accident in 2010. Species of common barberry plants (the alternate host of wheat stem rust) were found harbouring stripe rust. When transferred to grass hosts, Kentucky Bluegrass was