GLRaV-1 is one of a group of at least seven serologically distinct viruses that
appear in grapevine usually as mixed infection, causing the leafroll disease, the
worldwide most spread disease of Vitis. All common cultivars and rootstocks
can host the virus, but the american rootstocks usually do not develop any symptoms.
Most distinct symptoms can be observed on red wine cultivars. The leaf area turns
reddish with a small, green line along major veins. Leaves roll characterisitically,
and necrosis may appear on the upper epidermis. Ripening is delayed and carbohydrate
accumulation is reduced in the grapes. White cultivars often only show slight
yellowish discoloration of the leaves.
GLRaV-1 is usually transmitted by grafting onto infected, but symptomless
rootsrocks. To control its spread, testing of propagation material is required.