Garlic and other Allium species, Virus ..., (garlic, onions, leeks, shallots) - molecular detection (RT-PCR) and identification (sequencing).

Several species of viruses that can affect species of Allium (garlic, onions, leeks, shallots). Plant infection by these viruses has important repercussions for the production of bulbs is greatly reduced (up to 50 to 88%) even though the infection does not kill the plant.

Infection can occur by more than 8 different viruses that can cause infection in partnership forming a viral complex (Garlic viral complex, viral Complex garlic) that causes the disease called "mosaic of garlic" (Garlic mosaic) in that would involve two or more viruses of the genera Potyvirus, Carlaviruses and / or Allexivirus. This disease is characterized by the yellow striped, diffuse chlorotic spots, twisted leaves and mosaics.

These viruses have an RNA genome and belong to three different genera: Potyvirus, Carlavirus and Allexivirus. Species of these viruses are:

Potyvirus genre:

  • OYDV: Onion Yellow Dwarf virus (small yellow onion).
  • LYSV: Leek Yellow Stripe Virus (virus yellow lined leek).
  • SYSV: Shallot Yellow Stripe virus (striped yellow shallot).
  • WoYSV: Welsh Onion Yellow Stripe virus (Welsh onion yellow striped).

Carlaviruses genre:

  • GCLV / GarCLV: Common Garlic Latent Virus (Garlic common latent virus).
  • SLV: Shallot Latent virus (latent virus shallot). This virus is considered equal or at least antigenically related, and differ in their heat inactivation.

Allexivirus genre:

  • GVX: Garlic virus X (X garlic virus).
  • ShVX: Shallot virus X (shallot virus X).
  • Garlic Mite Borne Filamentous virus (filamentous virus transmitted by mites garlic).

Recommended diagnostic methods

Methods have been used to detect antigens of such viruses as immunoenzymatic methods of various forms of design (ELISA, Dot ELISA, Blotting Immunoassay), but all generally encounter two problems: limited sensitivity and difficulty have specific antibodies to detect each of these viruses).

For these reasons they are currently imposing molecular methods of RT - PCR to increase the sensitivity and speed.

Tests in IVAMI

  • RT-PCR for each of the viruses mentioned.

samples recommended

  • Leaves of plants with mosaic symptoms.

Preservation and shipment of samples:

  • Less than 48 hours introduced into sterile plastic container as possible be cooled (white- -corcho polystyrene container with frozen -frigolines- pack).
  • More than 48 hours frozen.

Delivering results:

  • 48 to 72 hours: molecular methods.  

Cost of the test: