Onion yellow dwarf virus
Onion yellow dwarf virus is a plant virus in the genus Potyvirus that has been identified worldwide and mainly infects species of Allium such as onion, garlic, and leek. The virus causes mild to severe leaf malformation, and bulb reduction up to sixty percent has been observed in garlic.
Genome
The full genome of OYDV is around 10,538 nucleotides long and encodes a polyprotein of 3,403 amino acids. Its P3 gene is longer than those of other known Potyviruses.OYDV is the first potyvirus found which has natural deletion mutants lacking the N-terminal region of helper-component proteinase. The mutant isolates are common. Garlic plants grown commercially are generally co-infected with both the normal and attenuated isolates. RNA silencing suppressor activities in isolates, which lack the long stretch of the N-terminal amino acids in their HC-Pro gene, are observed to be low.