COMPARATIVE MORPHO-ANATOMICAL STUDIES FOR TWO ASIMINA TRILOBA VARIETIES, PRIMA 1216 AND ITHACA

Asimina triloba (L.) Dunal ( Annonaceae ), pawpaw, is known for its edible fruits and therapeutical effects of root, stem, bark, leaves, fruit and seeds ( e.g. antimicrobial, antiviral, antitumour, anti-inflammatory). This study compares the morpho-anatomical structure of the stem and leaf of pawpaw, Prima 1216 and Ithaca variety cultivated in Romania. The cross sections (of lamina, vein, petiole and stem) and surface preparation (of lamina) were analysed with the Labophot II Nikon optical microscope and the Nova Nano SEM 630 electronic microscope. Both varieties have similar tissues with some different dimensional parameters of the leaf (length of non-glandular trichomes, area of epidermal cells from adaxial and abaxial epidermis, length and width of stomata, number of stomata/mm(2), Anumber of non-glandular trichomes/mm(2), Anumber of secretory cells/mm(2)). AThe leaf dimensional parameters of the Ithaca variety were larger than Prima 1216 variety, except for the area of epidermal cells from adaxial side of the leaf. Thus, the leaf from the Ithaca variety has more numerous non- glandular trichomes than Prima 1216: 13.17 f 0.87 pcs/mm(2) compared to 4.76 f 0.36 pcs/mm(2). AIthaca non- glandular trichomes are longer than Prima 1216 one: 44.31 f 0.54 mu m compared to 34.83 f 1.04 mu m. Statistically significant results (p < 0.05), demonstrate better adaptation of the Ithaca variety at an insufficient water input and high temperature.