Occurrence of grapevine leafroll-associated virus complex in the Republic of Macedonia (full paper)

Grapevine Leafroll-Associated Virus Complex is caused by several virus species (grapevine leafroll-associated viruses GLRaV -1, -3, -4, -5, -6, -9 and -10) belonging to the genus Ampelovirus, while GLRaV-2 is assigned to the genus Closterovirus. Because of its increasing economic importance, it is critical to determine which species of GLRaV are predominant in each region in Macedonia where this disease occurs. The laboratory test analyses used in this study consisted of a combination of two detection methods: serological test (DAS-ELISA) and RT-PCR based testing. The total number of 387 grapevine symptomatic samples from 17 regions including 27 localities, were surveyed from 2008 to 2013. All of these samples were tested for GLRaV-1, -2, -3, and -7, by using BIOREBA and SEDIAG DAS-ELISA kits, and the results showed that 55.9% (215 samples) were GLRaV positive. Out of the positive samples, 69.7% (150 samples) were single infections with GLRaV-3, 15.5% were single infections with GLRaV-1, and 14.8% were mixed infections with GLRaV-3 and GLRaV-1. Ten representative positive samples were analyzed with reverse-transcriptase polymerase chain reaction (RT-PCR) tests for GLRaV-1, GLRaV-2 and GLRaV-3. This is the first occurrence of Grapevine Leafroll-Associated Virus Complex, including GLRaV-1, GLRaV-2 GLRaV-3 and GLRaV-7 in the Republic of Macedonia