Raport i përditësuar mbi praninë e viruseve dhe viroideve në  vreshtat komerciale të Kosovës

UPDATED REPORT ON THE PRESENCE OF VIRUSES AND VIROIDS IN COMMERCIAL VINEYARDS OF KOSOVO

Toufic Elbeaino1, Agron Bunjaku2, Bekri Xhemali2, Gazmend Gjinovci2, Dajana Frashëri1, Michele Digiaro1

¹Istituto Agronomico Mediterraneo di Bari, Via Ceglie 9, 70010 Valenzano (BA), Italy.

²Kosovo Institute of Agriculture, Laboratory of Plant Protection, St. Adem Jashari 244, 30000 Peja, 7, Kosovo.

A search for virus and virus-like diseases was carried out in 25 commercial vineyards of Kosovo. One hundred fifty-five samples were collected from 4 grapevine-growing regions, i.e., Rahovec, Suharekë, Prizren and Malishevë, form which the local varieties and numbers of samples were, respectively, Prokupa (24 vines), Plovdina (15), Riesling Italian (26), Smederevka (20), Muskat Hamburg (22), Vranq (28) and Melnik (20). The serological (DAS-ELISA) and molecular (RT-PCR) laboratory analyses conducted on theses samples showed that grapevine fleck virus (GFkV) was the most widespread with an infection rate of 44.5%, followed by grapevine virus A (GVA, 40%), grapevine leafroll-associated virus 1 (GLRaV-1, 29%), GLRaV-3 (15.5%), GLRaV-2 (0.65%), whereas other relevant viruses, i.e., grapevine fanleaf virus (GFLV), arabis mosaic virus (ArMV) and grapevine virus B (GVB), were all absent. At the variety level, Muskat Hamburg showed the highest rate of infection (27.1%), followed by Melnik (26.5%) and Smederevka (21.3%). The infections in other cultivars had ranged between 9.7% and 16.8%. To acquire more information on the sanitary status of the collected samples, additional laboratory assays for the presence GVD, GVE, GVF and of viroids infecting grapevine, i.e., hop stunt viroid (HSVd), grapevine yellow speckle viroids 1 and 2 (GYSVd-1, -2) and Australian grapevine yellows viroid (AGYVd), were further conducted. RT-PCR results showed that GVD was present in one vine of Melnik cultivar (0.65%), whereas GVE and GVF were present in two vines each, with an infection rate of 1.3%. Results also showed that the HSVd, GYSV1 and 2 infections were high in almost all samples, with infection rates of 91%, 79% and 62%, respectively, whereas AGYVd was not detected. To date, only two surveys, targeting viruses diseases had been conducted to verify the sanitary status of the most important grapevine varieties in Kosovo (Dida et al., 2017; 2012). The virus infection rates found in this investigation had reconfirmed all those reported from both surveys; in addition to the first-time report on the presence of GVD, GVE, GVF, HSVd, GYSVd1 and 2 in the Kosovar grapevine. Although a high incidence of viroids was found in the tested samples, which is very common almost to all grapevine cultivars worldwide; in general, the very low infection rates found for important grapevine viruses, i.e., GFLV, GLRaV-2, GLRaV-3, GVD, GVE and GVF, together with the absence of ArMV and GVB is considered as an assist for selecting healthy grapevine material for propagation an\or for a certification program for grapevine at the national level.

Key words: Kosovo, grapevine, viruses, viroids, ELISA, RT-PCR.