Phenotypical, Sanitary and Ampelometric Variability within the Population of cv. Plavac Mali (Vitis vinifera L.)

Abstract

Summary One hundred and sixty individual vines representative of the entire growing region for cv. Plavac Mali (Middle and Southern Dalmatia) were ampelographically analyzed in situ during a period of four years. High phenotypical variability was determined in: the maturity period (35.6% “early maturity” vs. 11.9% “late maturity”), colouring (>50% of vines had bunches that were not coloured completely) and density of bunches, and degree of fi rmness of fl esh and size of the berries. In a sample of 36 vines harvested in 2005 high variability was determined in: parameters of fertility, sugar content (range 66139°Oe), and the size parameters of bunches. Th e samples were tested for the presence of four viruses by ELISA test (Grapevine Fanleaf Virus (GFLV), Arabis Mosaic Virus (ArMV), Grapevine Leafroll associated Virus 1 and 3 (GLRaV-1 and GLRaV-3). 91% of all analyzed samples tested positive for GLRaV-3, while an infection with the ArMV (6%) was the least common. Only 5% of genotypes resulted as negative in virus testing. Th e results of the research point to a signifi cant degree of intra cultivar genetical variability and the necessity of further individual clonal selection.