Eggplant mottled dwarf virus (EMDV)

General

• Nucleorhabdovirus first described on eggplant in 1969 in Italy.
• Virus also described under the name Tomato vein yellowing virus or Pittosporum vein yellowing virus.
• Endemic to eggplant and tomato production areas of the Mediterranean Basin in particular (Turkey, Greece, Maghreb, Portugal, France, Spain-Canary Islands-; etc.). Now also found in Jordan, Afghanistan, Iran, Bulgaria, etc.
• Virus rather confined to Solanaceae, attacking tobacco, tomato, , pepper potato Solanum nigrum, S. sodomaeum , ; it is especially occasionally damaging to eggplant in France with regard to cultivated vegetables. It also affects cucumber, melon, Hibiscus rosa-sinensis, Lonicera sp., Pittosporum tobira and Capparis spinosa.
• Organs attacked  : leaves, more rarely fruits.
• Symptoms :
  • Chlorotic mottling on the blade of young leaves.
  • Thinning and yellowing of the veins of young leaves, and adjacent tissues.
  • Crumpled leaves, more or less deformed, or even partially rolled up, of reduced size.
  • Fruits few, small, deformed, showing some corky brownish longitudinal lesions.
  • Reduced or even blocked plant growth. They end up being sterile.
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• Signs : no visible sign.
• Possible confusion : Physostegia chlorotic mottle virus (PhCmoV), virus of the same family emerging in France.

Biology

• Conservation : is probably perpetuated in the crop environment by cultivated alternative hosts and weeds, considered as virus reservoirs.

• Transmission : the distribution of diseased plants in the field suggests the intervention of an inefficient insect vector. So far, a species of leafhopper has been shown to Agallia vorobjevi (Homoptera: Cicadellidae) transmit the virus.

Protection

• Protect nurseries and young plants in the field with non-woven sails (Agryl P17 type) or mesh fabrics (Filbio type).
• Avoid setting up a new crop near old crops that may already be contaminated
• Carefully weed the plots and their surroundings in order to eliminate sources of viruses and / or vectors.
• Eliminate the first infected plants.
• Chemical control against the potential vector (s) of this virus is not easy to implement, the nature and biology of the latter being still poorly understood.