Corn Viruses Flashcards
What is the causal organism of corn stunt?
Spiroplasma kunkelii (a virus)
What is a mollicute?
has no cell wall
Where is the corn stunt virus found in the plant?
phloem
What is the vector for corn stunt?
leafhoppers
In what manner does corn stunt survive in leafhoppers?
persistent and propagative (replicates in leafhoppers)
Where does corn stunt overwinter?
in leafhoppers
What is Spiroplasma kunkelii?
a virus that causes corn stunt
What shape is the corn stunt virus?
spiral (easy to identify)
Where in the world is corn stunt present?
North and South America Only
What are two symptoms of corn stunt?
stunting growth, loose to?oth ears?, reddening
Which leaves turn red first in response to corn stunt?
Older leaves
What is a Dalbulus maidis?
leafhopper
What causes maize dwarf mosaic?
maize dwarf mosaic virus
How is maize dwarf mosaic virus transmitted? (3 ways)
Aphids in a non-persistent manner, seed transmitted (rare), mechanically through leaf rubbing
What does MDMV stand for?
maize dwarf mosaic virus
What alternate hosts does maize dwarf mosaic virus infect? (2)
Johnsongrass and sorghum
Where is maize dwarf mosaic virus in the USA?
Eastern USA starting at Texas and moving East
List 2 symptoms of MDMV
chlorotic spots and streaks on green, young leaves
stunting
How long does it take for MDMV symptoms to appear?
six weeks after aphids feed and transmit the virus
List three ways to manage MDMV
Tolerant corn hybrids
Avoid aphids
Control of Johnsongrass with herbicides
What is MCDV?
Maize chlorotic dwarf virus
What is Waikavirus?
Maize chlorotic dwarf virus
How is maize chlorotic dwarf virus transmitted?
leafhoppers, semi-persistently
What is Greminella nigrofons?
a leafhopper that is the most important maize chlorotic dwarf virus vector
Is MCDV or MDMV more widespread in USA?
MDMV
List two disease control methods for MCDV.
Control Johnsongrass,
Control leafhoppers
How many states in the USA have Johnsongrass?
All 48 mainland states.
Are there variants of the MCDV?
Yes - 2 variants currently known