Indicator plant for tristeza virus in citrus is

Indicator plant for tristeza virus in citrus is C. aurantifolia.
CTV is citrus tristeza virus, it is a viral species of the genus closterovirus that causes the most economically damaging disease of citrus.
CTV is classically diagnosed by graft-inoculating a Mexican lime (Citrus aurantifolia) with tissue from a diseased plant. Symptoms on the leaves begin as clear veins that turn corky, which is then followed by chlorosis and cupping of the leaf.