Rust

Question 1

What are the three types of rust diseases that occur on wheat?

Answer 1

1. Stem rust
2. Leaf Rust
3. Stripe Rust

Question 2

What is the primary host of rust disease

Answer 2

Primarily wheat but can infect barley and other grasses.

Question 3

What is the genus of rust?

Answer 3

Puccinia

Question 4

What is the causal agent for stem rust?

Answer 4

Puccinia Graminis

Question 5

What is the causal agent for leaf rust?

Answer 5

Puccinia Recondita

Question 6

What is the causal agent for stripe rust?

Answer 6

Punnicia striiformis

Question 7

What kind of trophs are Rust?

Answer 7

Obligate Biotrophs

Question 8

What is Heteroecious?

Answer 8

The lifecycle of a disease requires 2 hosts.
Ex: Wheat Stem Rust

Question 9

What is Autoecious?

Answer 9

The lifecycle of a disease requires 1 host.

Question 10

What are Macrocyclic diseases?

Answer 10

Disease cycles that produce all 5 possible types of spores.

Ex: Wheat stem rust

Question 11

What are Demicyclic Diseases?

Answer 11

Disease cycles that lack urediniospores.

Question 12

What are microcyclic diseases?

Answer 12

Disease cycles that produce only 2 types of spores.

Question 13

What kind of spores are produced on the barberry plant for wheat stem rust?

Answer 13

Spermatia and Aeciospores

Question 14

What are the host plants of wheat stem rust?

Answer 14

Barberry and Wheat

Question 15

What kind of spores are produced on the wheat plant for wheat stem rust?

Answer 15

Uridiniospores, Teliospoes and Basidiospores

Question 16

What is plasmogamy?

Answer 16

Fusion of cells without the fusion of the nucleus.

Question 17

What is Karyogamy?

Answer 17

Fusion of cells with the fusion of the nucleus

Question 18

Which spores are produced through Karyogamy?

Answer 18

Teliospores

Question 19

Which spores are produced through plasmogamy?

Answer 19

Uridiniospores and Aeciaspores

Question 20

What are symptoms of stem rust?

Answer 20

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.

Question 21

Which spore is produces asexually?

Answer 21

Uridiniospores. They have no genetic variation as they are clones.

Question 22

How does wheat stem rust travel to canada?

Answer 22

The urediniospores disseminate by wind from Mexico and USA and make its way up to Canada in increments.

Question 23

What are some ways to control wheat stem rust?

Answer 23

1. Most Important: Destruction of alternate host Barberry.
2. Earlier planting to avoid rust infection.
3. Foliar fungicide (not economical)

Question 24

How does leaf rust progress from southern USA and Mexico to Canada?

Answer 24

Uridiniospores overwinter on the what in the south and the disease progresses northward as the temperature increases.

Question 25

What are some symptoms of leaf rust?

Answer 25

Reddish pustules on leaves that are rounder and much smaller than the ones on stem rust. As the plant ripens teliospores appear.

Question 26

What is the alternate host for leaf rust?

Answer 26

Species of Thalictrum (Meadow Rue)

Question 27

What are some control methods for leaf rust?

Answer 27

1. Resistant cultivars 2. Early seeds 3. Foliar fungicide

Question 28

Where was the cultivar Lr34 for leaf rust resistance released?

Answer 28

Glenlea in 1972 by a man named Brent McCallum.

Question 29

What is the difference between homothallic and heterothalic?

Answer 29

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.