Lettuce big-vein disease explained

Lettuce big-vein disease
Hosts:	Lettuce
Causal Agents:	lettuce big-vein associated virus (LBVaV)
Vectors:	Olpidium brassicae
Treatment:	See text

Lettuce big-vein disease causes leaf distortion and ruffling in affected lettuce plants.

This disease was first associated in 1983 with a rod-shaped virus named lettuce big-vein associated virus (LBVaV), which is transmitted by the obligately parasitic soil-inhabiting fungus, Olpidium brassicae. However, in 2000, a second virus, Mirafiori lettuce big-vein virus (MLBVV), was found in lettuce showing big-vein symptoms. Furthermore, since the lettuce infected with LBVaV alone doesn't develop the symptoms while the infected with NLBVV one does, the latter virus is considered to be a main agent of the big-vein disease.^[1]

Symptoms

Affected plants have veins that become large and clear, causing the rest of the leaf to become ruffled. Severely infected plants may fail to form a lettuce head.^[2]

Control

Grow disease-resistant cultivars.
Use disease-free healthy seeds.
Treat with methyl bromide, chloropicrin, or dazomet solution.

Notes and References

Sasaya, T., H. Fujii, K. Ishikawa, H. Koganezawa . 2008 . Further evidence of Mirafiori lettuce big-vein virus but not of Lettuce big-vein associated virus with big-vein disease in lettuce . Phytopathology . 98 . 4 . 464–468 . 10.1094/PHYTO-98-4-0464 . 18944196 .
Web site: Big Vein . 24 June 2019 . University of California Integrated Pest Management Program.