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» Introductory Plant Pathology
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Current Category » Crop Disease and Management

Morphology of Viruses

Plant viruses are usually described as

1. Elongated (Rigid Rod or Flexious thread):

a. Rigid rod – (Ex) Tobacco mosaic virus (15 X300 nm)
Barley stripe mosaic virus (20x 10 nm).

b. Flexuous thread ( Ex) Potato virus X 10-13 wide upto 480 nm length , citrus tristeza virus ( 10-14 X 2000nm).

2. Rhabdo Viruses:

Bacillus like- These are short bacillus like rods approximately 3 to 5 times as long as they are wide.

(Ex): Potato yellow dwarf virus 75X 380 nm.
Wheat striate mosaic virus – 65X 270 nm.
Lettuce necrotic yellow virus – 52 X 300 nm.

3. Spherical (Isometric or Polyhedral) :  

All spherical viruses are actually polyhedral ranging in diameter about 17 nm to 60 nm.
Ex: Tobacco Necrosis satellite virus 17 nm in diameter.
Wound tumour virus 60nm in diameter.
Tomato spotted wilt virus 70-80 nm in diameter.

Current Category » Crop Disease and Management