A number of studies have highlighted differences in the density of stomata between Vitis species, but few have examined differences between varieties of V. vinifera. The density and size of the stomata in the lower epidermis of leaves belonging to 12 grapevine varieties, a direct producer hybrid (DPH) involving a V. vinifera and a non-vinifera parent, and the non-vini-fera rootstocks 'SO4' and '110-Richter', were therefore examined. Transparent nail polish peel prints of the area between the main and right lateral veins were produced for 10 leaves per variety. These prints were then examined under a light microscope and the number of stomata in a unit area of 0.196 mm2 counted. Image analysis software was then used to measure the length and width of all those counted. Rootstock 'SO4', 'Chasselas Dorée', 'Albariño' and 'Cabernet Sauvignon' had the highest stomatal densities (all > 34 stomata per unit area), while 'Castañal', 'Torrontés' and 'Caiño Blanco' and 'Jacquez' (DPH), had the smallest (all < 26.50 stomata per unit area). 'Treixadura' and 'Caiño Blanco' had significantly longer and wider stomata than all the other varieties examined; the DPH 'Jacquez' had among the shortest and narrowest. No relationship was seen, however, between mean varietal leaf size and the stomatal density or stomatal size; nor was any seen between the variables examined and the condition of belonging to V. vinifera or not.

VITIS - Journal of Grapevine Research, Vol. 55 No. 1 (2016): Vitis