Physiological response of Phlox paniculata L. varieties to different growing conditions of Western Siberia

Siberian Botanical Garden, National Research Tomsk State University, 36, Lenin Ave., Tomsk, 634050, Russia

^* Corresponding author: sbg-flowers@yandex.ru

Abstract

Physiological indicators of plants are essential characteristics of plant adaptation to adverse environmental factors. Phlox paniculata varieties (originated from North America) introduced into the southern taiga subzone of Western Siberia experience stress caused by numerous factors. The physiological response to different growing conditions of the southern taiga subzone of Western Siberia was analyzed for 3 varieties of Ph. paniculata. The study employed handheld optical instruments for vital analysis of plant physiological parameters: a compact LI-600P porometer (LI-COR) and a CI-710 leaf spectrometer (CID Bio-Science). Stomatal conductance of phlox leaves in partial shade studied with respect to different varieties was found to virtually remain unchanged. The studied varieties exhibit different degree of resistance to water deficiency. The variety ‘Stanislas’ was found to be resistant to insufficient soil humidity and light, it can be grown in both moderately shaded areas and arid conditions. The studied varieties showed high indices of anthocyanins and carotenoids under good light conditions and natural humidity, which indicates these conditions as the most stressful for Ph. paniculata due to a high degree of water and temperature stress. The greatest difference in the measured indices was found for the variety ‘Antarktida’, which indicates its susceptibility to water deficiency.