Life Cycle
Like other Puccinia species, P. graminis is an obligate biotroph and has a complex life cycle featuring alternation of generations. The fungus is heteroecious, requiring two hosts to complete its life cycle - the cereal host and the alternate host. There are many species in Berberis and Mahonia that are susceptible to stem rust, but the common barberry is considered to be the most important alternate host. P. graminis is macrocyclic (exhibits all five of the spore types that are known for rust fungi).
Animation of the stem rust life cycle is available here
P. graminis can complete its life cycle either with or without barberry (the alternate host).
Read more about this topic: Stem Rust
Famous quotes containing the words life and/or cycle:
“Art is beauty, and every exposition of art, whether it be music, painting, or the drama, should be subservient to that one great end. As long as nature is a means to the attainment of beauty, so-called realism is necessary and permissable [sic], but it must be realism enhanced by idealism and uplifted by the spirit of an inner life or purpose.”
—Julia Marlowe (1866–1950)
“The cycle of the machine is now coming to an end. Man has learned much in the hard discipline and the shrewd, unflinching grasp of practical possibilities that the machine has provided in the last three centuries: but we can no more continue to live in the world of the machine than we could live successfully on the barren surface of the moon.”
—Lewis Mumford (1895–1990)