Comparative scanning electron microscopy investigations on some characteristics of the pollen aperture complex in seedless grape <em>Vitis vinifera</em> L. cultivars

In the 1989-1994 period, a palynological study of 66 seedless grape cultivars, varieties and hybrid vine forms was made. On the basis of scanning electron microscopy observations on the pollen aperture complex elements and on the statistical treatment of the results obtained, the following conclusions were drawn : 1 - In seedless grape cultivars, characterized by functionally male type of flowers, there are no significant differences in the shape of colps and the surface structures on the pollen aperture complex. 2 - The classification of seedless cultivars according to pollen surface is arbitrary and the differences in the parameters are not confirmed by the mathematical treatment of aperture elements. 3 - The mean dimensions of the most important pollen aperture complex elements in seedless grape cultivars are the following: polar axis: 23,48 μm ; equatorial axis: 15,37 μm ; mesocolpium : 11,61 μm ; apocolpium : 4,85 μm, colplength : 20,93 μm ; colp width : 0,92 μm, colpdepth : 0,60 μm