Rust Flashcards
What are the three types of rust diseases that occur on wheat?
- Stem rust
- Leaf Rust
- Stripe Rust
What is the primary host of rust disease
Primarily wheat but can infect barley and other grasses.
What is the genus of rust?
Puccinia
What is the causal agent for stem rust?
Puccinia Graminis
What is the causal agent for leaf rust?
Puccinia Recondita
What is the causal agent for stripe rust?
Punnicia striiformis
What kind of trophs are Rust?
Obligate Biotrophs
What is Heteroecious?
The lifecycle of a disease requires 2 hosts.
Ex: Wheat Stem Rust
What is Autoecious?
The lifecycle of a disease requires 1 host.
What are Macrocyclic diseases?
Disease cycles that produce all 5 possible types of spores.
Ex: Wheat stem rust
What are Demicyclic Diseases?
Disease cycles that lack urediniospores.
What are microcyclic diseases?
Disease cycles that produce only 2 types of spores.
What kind of spores are produced on the barberry plant for wheat stem rust?
Spermatia and Aeciospores
What are the host plants of wheat stem rust?
Barberry and Wheat
What kind of spores are produced on the wheat plant for wheat stem rust?
Uridiniospores, Teliospoes and Basidiospores
What is plasmogamy?
Fusion of cells without the fusion of the nucleus.
What is Karyogamy?
Fusion of cells with the fusion of the nucleus
Which spores are produced through Karyogamy?
Teliospores
Which spores are produced through plasmogamy?
Uridiniospores and Aeciaspores
What are symptoms of stem rust?
Redish pustules form on stems and a little bit on leaves. Lesions are long and oval (Uridiniospores).
Later in the season, the plant ripens and the pustules become dark teliospores.
Which spore is produces asexually?
Uridiniospores. They have no genetic variation as they are clones.
How does wheat stem rust travel to canada?
The urediniospores disseminate by wind from Mexico and USA and make its way up to Canada in increments.
What are some ways to control wheat stem rust?
- Most Important: Destruction of alternate host Barberry.
- Earlier planting to avoid rust infection.
- Foliar fungicide (not economical)
How does leaf rust progress from southern USA and Mexico to Canada?
Uridiniospores overwinter on the what in the south and the disease progresses northward as the temperature increases.
What are some symptoms of leaf rust?
Reddish pustules on leaves that are rounder and much smaller than the ones on stem rust.
As the plant ripens teliospores appear.
What is the alternate host for leaf rust?
Species of Thalictrum (Meadow Rue)
What are some control methods for leaf rust?
- Resistant cultivars
- Early seeds
- Foliar fungicide
Where was the cultivar Lr34 for leaf rust resistance released?
Glenlea in 1972 by a man named Brent McCallum.
What is the difference between homothallic and heterothalic?
Homothalus organisms are capable of sexual reproduction on a single organism opposite sexes are different cells on the same thallus.
Heterothalus organisms are capable of sexual reproduction only in the presence of genetically different mycelia.
