Evaluation of olive cultivars with different photosynthetic activity of leaves

In the Crimea olive breeding is concentrated at Nikita Botanical Gardens, Yalta. At the beginning of the 20^th century, Nikita Botanical Gardens initiated the olive breeding program in order to select new genotypes suitable for the fruit growing areas of the Crimea (44°30.83’N; 34°14.16’E). The research purpose was to investigate and sort out olive cultivars with high functional activity of the leaf system. Investigations had been carried out in 2013-2015 in the laboratory on intact leaf plates of three olive cultivars (‘Nikitskaya Krupnoplodnaya’, ‘Tiflis’ and control cultivar for comparison – ‘Ascolana’). These cultivars were selected using the complex of economically valuable traits. The leaves on shoots with fruits and without growing on different canopy parts were chosen for analysis. Photosynthetic activity was characterized by chlorophyll fluorescence parameters (Kautsky effect). Chlorophyll fluorescence was measured on a portable fluorometer. The control cultivar ‘Ascolana’ presents the most effective functioning of leaves with fruits, located at the top and middle of canopy. This cultivar is characterized with small size of light-absorbing complex (F_m), moderate activity of primary photosynthesis reactions (F_v/F_о) and balanced work of photochemical process (F_m-F_st)/F_m). ‘Nikitskaya Krupnoplodnaya’ has the highest functioning of leaves from the middle canopy. Photoactivity and degree of efficiency appears due to large size of light-absorbing complex (F_m) and considerable part of structures “background” chlorophyll (F_о). Cultivar ‘Tiflis’ has variants involving leaves from the middle part of canopy with volume light-absorbing complex and considerable content of “background” chlorophyll, but weak efficiency of photochemical process, as well as leaves with fruits from the top of canopy, characterized with balance of all photoactivity parameters. Contrast of olive cultivars according to rating parameters of their photosynthetic activity was found out as a result of researches.