Leaf anatomical alterations induced by drought stress in two avocado cultivars G. KOFIDIS, A. M. BOSABALIDIS and K. CHARTZOULAKIS Abstract The avocado (Persea americana Mill.) leaf is hypostomatic with the typical anatomical pattern of dicots. The palisade parenchyma of the mesophyll is composed of an upper layer with elongated, densely arranged cells, and of a lower layer with short and loosely placed cells. Within the mesophyll, numerous idioblastic oil cells occur. In the avocado cultivars studied ('Hass' and 'Fuerte'), drought stress resulted in an increase of the density of the epidermal cells and mesophyll chlorenchyma cells with a parallel decrease of their size. Mesophyll intercellular spaces increase in volume and oil cells become more numerous. The above features are much more prominent in 'Hass', a fact favouring the suggestion that 'Hass' responds to drought stress better than 'Fuerte'.   < back .