Girish Mahajan (Editor)

Potato spindle tuber viroid

Updated on
Edit
Like
Comment
Share on FacebookTweet on TwitterShare on LinkedInShare on Reddit
Group
  
Viroids

Genus
  
Rank
  
Species

Family
  
Higher classification
  
Pospiviroid

Potato spindle tuber viroid wwwapsnetorgedcenterintropplessonsvirusesAr

Scientific name
  
Potato spindle tuber viroid

Similar
  
Pospiviroidae, Avocado sunblotch viroid, Potato leafroll virus, Peach latent mosaic vi, Hop stunt viroid

The Potato spindle tuber viroid ("PSTVd") was the first viroid to be identified. PSTVd is a small, circular RNA molecule closely related to the chrysanthemum stunt viroid. Present within the viroidal RNA is the Pospiviroid RY motif stem loop. The natural hosts are potatoes (Solanum tuberosum) and tomatoes (Solanum lycopersicum). All potatoes and tomatoes are susceptible to PSTVd and there is no form of natural resistance. Natural infections have also been seen in avocados and infections in other solanaceous crops have been induced in the laboratory.

Contents

Potato spindle tuber viroid Potato spindle tuber viroid PSTVD0Photos EPPO Global Database

Strains and their symptoms

Potato spindle tuber viroid Potato spindle tuber viroid PSTVD0Photos EPPO Global Database

Different strains of PSTVd exist and symptoms range from mild to severe. Mild strains produce no obvious symptoms. Symptoms in severe strains are dependent on environmental conditions and are most severe in hot conditions. Symptoms may be mild in initial infections but become progressively worse in the following generations. Common symptoms of severe infections include colour changes in the foliage, smaller leaves and spindle like elongation. Sprouting also occurs at a slower rate than in unaffected potatoes. Infected tomatoes are slower to show symptoms which include stunted growth with a ‘bunchy top’ caused by shortened internodes. Leaves become yellow or purple and often become curled and twisted. Necrosis eventually occurs in the veins of the bottom and middle leaves and the top leaves don’t die but are reduced in size. Fruit ripening is also affected leading to hard, small, dark green tomatoes.

Potato spindle tuber viroid Viroid Kids Encyclopedia Children39s Homework Help Kids Online

Long distance spread of PSTVd usually occurs via infected seeds but transmission via aphids (Myzus persicae) also occurs but only in the presence of PLRV (potato leaf roll virus). Mechanical transmission also occurs once it has been introduced to an area.

Primary and secondary structure of PSTVd

PSTVd comprises 359 nucleotides.

The nucleotides that are highlighted are found in most other viroids.

Potato spindle tuber viroid Potato spindle tuber

Potato spindle tuber viroid Potato spindle tuber viroid Department of Agriculture and Food

Potato spindle tuber viroid Potato spindle tuber viroid

References

Potato spindle tuber viroid Wikipedia