GLRaV1

GLRaV-1 stands for Grapevine leafroll-associated virus 1, a positive-sense RNA virus in the family Closteroviridae, genus Ampelovirus. It is one of several viruses associated with grapevine leafroll disease, a condition that affects Vitis vinifera and other grape species.

Infection and symptoms: GLRaV-1 primarily infects grapevines and can cause leafroll symptoms such as downward-curled leaves with interveinal reddening or yellowing, depending on the cultivar. Symptoms are often more evident in red-fruited varieties. Infected vines may show reduced vigor, delayed budbreak, lower yield, and altered fruit quality, particularly when co-infected with other grapevine viruses.

Genome and biology: The virus has a relatively large positive-sense RNA genome, typically around 16 to 19 kilobases, encoding replication, movement, and structural proteins. GLRaV-1 particles are filamentous and phloem-limited, a characteristic shared with related ampelo- and closteroviruses.

Transmission and ecology: GLRaV-1 is transmitted by certain mealybugs and scale insects in a semi-persistent manner. Transmission is not accomplished through pollen or seed. Vector populations and feeding behavior influence spread within vineyards.

Diagnosis and management: Detection relies on serological assays such as ELISA and molecular methods like RT-PCR or RT-qPCR. Management emphasizes using certified virus-free planting material, routine indexing, rogueing of infected vines, and vector control through cultural practices and targeted pest management.

Distribution: The virus is widely distributed in grape-growing regions worldwide and commonly occurs in planta with other grapevine leafroll viruses. See also: grapevine leafroll disease.