Introduction of viruses and viral diseases

Question 1

What is a virus?

Answer 1

It is an infectious agent that can only replicate inside a living cell. It contains at least one nucleic acid and one protein.

Question 2

How many virus species are known to cause plant disease?

Answer 2

1,743

Question 3

How many virus particles would occupy only 1% of the volume of the cell?

Answer 3

about 10 million.

Question 4

What are the six characteristics of viruses?

Answer 4

1. Size
2. Shape
3. Number of particles
4. Coating type
5. Type of nucleic acid
6. Sequence

Question 5

What are the two shapes of viruses?

Answer 5

1. Helical
2. Icosahedral (spherical)

Question 6

How can viruses enter the plant?

Answer 6

Through wounds and vectors.

Question 7

What are the three steps for infectious processes of viruses?

Answer 7

1. Virus enters plant cell.
2. Replication
3. Movement

Question 8

What are seven symptoms caused by viruses?

Answer 8

1. Mosaic
2. Stunting
3. Ringspots
4. Big vein
5. Stem pitting
6. Vein banding
7. Enation

Question 9

What is the host range for tobacco mosaic virus?

Answer 9

Greater than 350 species

Question 10

How does TMV enter the host?

Answer 10

Through wounds.

Question 11

What are 5 signs of TMV?

Answer 11

1. Mosaic
2. Stunting
3. Vein-yellowing
4. Malformation
5. Yield reduction

Question 12

What are 3 ways to manage TMV?

Answer 12

1. Wash tools with 10% bleach.
2. TMV-contaminated solids should be discarded.
3. Transgenic plants offer alternative strategies.

Question 13

What was the first virus identified and described?

Answer 13

TMV

Question 14

What is the largest group of viruses?

Answer 14

Potyvirus group.

Question 15

What are two symptoms of potato virus Y?

Answer 15

Mottle and stunting

Question 16

What are three host plants for potato virus Y?

Answer 16

Tobacco, Tomato and Potato

Question 17

How does potato virus Y spread?

Answer 17

Aphids and potato seed pieces

Question 18

What is the host range for plum pox virus?

Answer 18

Stone fruits, ornamentals, and wild species.

Question 19

When was plum pox virus first detected in Canada?

Answer 19

in 2000

Question 20

How can you manage trees with plum pox virus?

Answer 20

Need to remove the tree.

Question 21

What is the host range for tomato brown rugose fruit virus?

Answer 21

Tomatoes and Peppers.

Question 22

When was tomato brown rugose first detected in Canada?

Answer 22

First time 2019 in a greenhouse in Ontario and then in 2020 in a greenhouse in Alberta.

Question 23

What are 3 symptoms of tomato brown rugose fruit virus?

Answer 23

1. Discoloration and mosaic on leaves.
2. Brown wrinkled necrotic areas on green fruit.
3. Blotching, crinkling, and yellow to brown necrotic areas on skin on mature fruits.