EVALUATION OF THE MORPHOLOGICAL STRUCTURE VARIABILITY IN MALE AND FEMALE ACTINIDIA DELICIOSA PLANTS LEAVES WITHIN THE CONDITIONS OF THE RUSSIAN HUMID SUBTROPICS

Differences in the anatomy, morphology of leaves and petioles of Actinidia deliciosa (kiwi) can play an important role in determining sex. Three months after budding (in June), kiwi leaves on male and female plants, grown on vegetative and generative shoots, had different leaf areas (128.6 ±13.45 cm2 in male and 104.5 ±4.02 cm2 in female plants) and shapes. The most common leaf shape was defined as "folium cordatum" and "folium rotundato-cordatum". Higher values of the total thickness of female leaves (190 ±3.84 microns) compared with male leaves (174.7 ±3.52 microns) were estimated, which led to thickening of the adaxial epidermis of the leaves and especially the palisade parenchyma of female leaves (136 ±2.76 microns compared with 104 ±1.61 microns in male leaves). Hypostomatic leaves with anomocytic stomata were observed in male and female plants. The main type of leaf venation is reticulated. Stellate multicellular trichomes on the abaxial side of the leaf were observed in leaves of both sexes. No significant differences were found in the structure of the vascular system of leaves and petioles. Experimental results showed that the ratio of the length of the terminal stomatal cells to the width was significantly different in male and female plants, exceeding 3 in male and less than 3 in female. The shape of the leaves and the appearance of the petioles were slightly different. It was used as a marker for identifying male and female kiwifruit plants. Thus, the thickness of the leaf and the morphology of the surface of the adaxial epidermis of the leaf, the ratio of the length and width of the stomata can be considered important structural parameters for sex determination.