Citrus Tristeza Virus

Detection of Citrus Tristeza Virus

Citrus Tristeza Virus (CTV) is a plant pathogen from the Closterovirus family. Citrus Tristeza Virus causes a severe disease named Tristeza which affects most varieties of citrus: sweet orange, mandarin, grapefruit, lime (but not lemon) most of the time when they are grafted on sour orange. Tristeza is naturally vectored by several species of aphids. The aphid can acquire the virus after feeding on infected plants for 5 to 60 minutes; but cannot transmit the virus anymore after 1 day : it is a non-persistent transmission. CTV is distributed worldwide wherever citrus trees grow. There are three distinct syndromes of CTV infection: quick decline, stem pitting, and seedling yellows. Different strains of CTV may vary in severity.

Decline includes chlorotic leaves and general dieback. It can be slow, lasting several months to years after the first symptoms are noticed. But may also be quick, resulting in host death just days after the first symptoms are noticed.
Stem pitting is recognizable by pits in the trunk and stem.
Seedling yellows symptoms include yellowing of foliage and general dieback.

Citrus tristeza virus is considered to be one of the most destructive citrus viruses and has destroyed millions of trees worldwide. It is absolutely necessary to detect as soon as possible the virus, in order to be able to act in favor of its eradication.