Box and whisker plots of Yangling Grape Germplasm Repository. The median and mean value are indicated by the horizontal bar and the plus sign inside the box, respectively; the height of the box represents the interquartile range (IQR), which is the difference between the third quartile and the first quartile of the data. The whisker (the vertical lines from the top and bottom of the box) extends to a distance of 1.5 times IQR. Data outside these whiskers are marked by the black dots. The numbers in front of the black dots represent the accession numbers (Table 1). V-T, table grape cultivars of V. vinifera; V-W, wine grape cultivars of V. vinifera; LV-T, table grape cultivars of hybrids between V. labrusca and V. vinifera; AL-T, table grape of hybrid between V. aestivalis and V. labrusca; R-T, table grape of V. rotundifolia.