THE ASSIMILATION APPARATUS OF CLIMBING ROSES DURING INTRODUCTION IN A HUMID SUBTROPICAL CLIMATE

The dynamics of the physiological parameters of climbing rose leaves, characterized by immunity to biotic stressors in a humid subtropical climate, is presented. The objects of research are the cultivars ‘Domaine de Courson’, ‘Dortmund’ (control), ‘Elegance’, ‘Breath of Life’. The physiological parameters of assimilation apparatus were studied – the content of dry substances, specific leaf surface density (SLSD), the content of pigments, and parameters of slow chlorophyll a fluorescence induction. As a result, seasonal rhythms in the dry matter content were noted (on average from 36.9 ±2.3 to 41.2 ±1.2 %); cultivars resistant to phytopathogens were quantitatively isolated. Changes in the SLSD during the growing season are similar to the amount of dry matter. Cultivars ‘Domaine de Courson’, ‘Dortmund’ and ‘Elegance’ had higher rates relative to ‘Breath of Life’ throughout the season. The nature of changes in green pigments and carotenoids is similar. The highest amount of chlorophylls was registered in June – 1.865 ±0.353 mg/g of dry weight; the lowest was in August – 1.544 ±0.145 mg/g. The amount of carotenoids also ranges from 0.355 to 0.050 mg/g during the season, with maximum values in June and minimum values in August, 0.411 ±0.059 and 0.308 ±0.011 mg/g, respectively. The interrelation of physiological parameters with abiotic environmental factors was established. The dry matter content is significantly affected by air temperature (r = 0.91). The SLSD is markedly correlated with hydrothermal parameters and illumination level, while the relationship with temperature (r = 0.69) and humidity (r = 0.69) of air is direct; relationship with the luminous magnitude is inverse (r = -0.73). High correlations of air temperature and the parameters "viability index" (r = -0.81) were noted; very high ones are between "the calculated coefficient of photosynthetic activity" and "the coefficient of photosynthetic activity" (r = -0.93 and -0.91, respectively). Correlations between physiological parameters, a high dependence in the content of dry substances and specific leaf surface density are highlighted.