Structural and functional features of leaves in some Ficus carica L. cultivars in situ and in vitro

This paper presents the results of morphology, anatomy, photosynthetic activity and water regime studies in the leaves of common fig cultivars with and without symptoms of fig mosaic disease (FMD), growing in the collection plots of Nikita Botanical Gardens. In the common fig cultivar ‘Medovyiy’ with FMD symptoms, significant decrease was noticed in the linear dimensions of the leaves compared to symptomless plants. Reliable differences in adaxial epidermis thickness of the cultivars ‘Medovyiy’ and ‘Smena’ were identified. Index of chlorophyll fluorescence induction varied from 0.75 and 0.73 in the symptomless plants of the cultivars ‘Medovyiy’ and ‘Smena’ and decreased to 0.63 and 0.69 in plants with FMD symptoms, respectively. Leaf tissue structure features in the microshoots of some common fig cultivars grown in vitro was studied for preliminary evaluation of their adaptive potential. Among four studied cultivars, the highest palisade index was noticed for the cultivars ‘Pomoriyskiy’ (0.44%) and ‘Medovyiy’ (0.40%). Analysis of water fractional composition demonstrated that free water proportion in the total water content was lowest in the common fig cultivar ‘Medovyiy’ – 21.26% and highest in the cultivar ‘Figue Jaune’ – 32.42%. Our investigations demonstrated that the cultivar ‘Medovyiy’ was characterized by high plasticity potential that could be possibly realized under the following adaption to in vivo conditions due to the small cells of the covering tissue and the large number of the trichomes and the stomata.