Photosynthetic activity in freesia leaves as an index for early selection of stable genotypes

The area of the Black sea coast of Krasnodar region is one of those few in Russia and the former Soviet Union, where it is possible to grow Freesia without huge energy costs. Thus, the non-heated glass greenhouses are used under adverse weather conditions in the city of Sochi during autumn, winter and spring period. Therefore, the actual task is to get winter-resistant forms. The efficient photosynthetic apparatus can provide a clear idea about the adaptive potential of the given plant, which consists of the adaptive capacity of individual organs. We have studied a functional state of the photosynthetic apparatus in leaves of different Freesia genotypes (the following cultivars: Georgiy Pobedonosets, Goluboi Zhemchug, Iney, Vega, Elizabet, Gold River, Gabriel; and hybrids: I-108-1, K-86-4, L-10-3, P-28-1, P-30-1, H-10-14, P-34-1, P-28-3, P-24-1) according to the parameters of slow dynamics of chlorophyll fluorescence in plant development dynemics. The steady-state level of fluorescence (F_T), level of viability (Fm/F_T), indicator of photosynthetic activity by extrapolation algorithm (Kf_T), and photosynthetic activity index, calculated at each instant moment of the measurements (Kf_n) were estimated. Domestic varieties and hybrids of Freesia that are stable and well adapted to winter in the greenhouse with uncontrolled conditions are identified, i.e. Goluboi Zhemchug, Elizabet (triploid), I-108-1, K-86-4, L-10-3, P-28-1, P-30-1, P-34-1.