Características morfo-anatómicas de cultivares tintas de videira (Vitis vinifera)

Mestrado em Engenharia Agronómica - Protecção das Plantas - Instituto Superior de AgronomiaThe objectives of this work consisted in studying the anatomical leaf-biometric characteristics of red grapevine cultivars, 'Aragonez', 'Cabernet Sauvignon', 'Syrah' and 'Touriga Nacional', throughout the season, on field conditions. The studies were conducted using light and scanning electron microscopy. Epidermal features, such as the thickness of the cuticle, the stomatal index, the shape and dimensions of epidermal cells in the leaf surface and distribution of trichomes are similar. The stomata are of two types, the actinocytic type, already referred to the genus Vitis, and the staurocytic type. The stomata size is very diverse: large and small stomata coexist side by side. The cvs. 'Cabernet Sauvignon' and 'Touriga Nacional' present spongy parenchyma with less air intercellular spaces, in opposition to the cvs. 'Aragonez' and 'Syrah. It was also found that, in cross sections, the lumen of the cells of 'Touriga Nacional' and 'Cabernet Sauvignon' is higher than in the other cultivars. The main leaf of cv. 'Aragonez' stands out for its higher leaf area and the cv. 'Cabernet Sauvignon' by the lowest. In summary, in the four cultivars leaves were observed similar anatomical features but with a different organization of the mesophyll and with different thicknesses of epidermal cells, that might be responsible for the differences found in the resistance to stress environmental conditions