Studies on table grape germplasm grown in Northern Greece. 2. Seedlessness, berry and must characteristics

From 1991 to 1993 nine quantitative and qualitative characteristics of the grape berry and its must were evaluated using local and introduced table grape cultivars of the grapevine collection of the Greek Gene Bank. The data indicate a distinct variation in the grape germplasm in all characters and demonstrate the usefulness of the genetic material as a donor of important genes for grapevine improvement. Principal Component Analysis (PCA) produced 2 factors representing 68.1% of the total variation. PC 1 , explaining 43.6% of the total variance, is highly correlated with berry size parameters and characteristics of the berry structure. By Cluster Analysis the assessed cultivars were separated into distinct groups; while seedlessness, was associated with small berry detachment force from the pedicel, late maturity was combined with high acid and low sugar content and a large number of seeds per berry was accompanied by low sugar content.