WATER REGIME OF SOME REPRESENTATIVES OF THE GENUS IRIS L. DURING INTRODUCTION IN THE SOUTHERN URALS

Abstract

The article presents the results of a study of the parameters of the water regime of irises of the subgenus Xyridion introduced in the Southern Urals (Iris graminea, I. halophila, I. halophila var. sogdiana, I. notha, I. orientalis, I. spuria, I. spuria subsp. carthaliniae, I. spuria subsp. musulmanica) in comparison with local species (I. sibirica, I. pseudacorus, I. pumila). The experiments were carried out on the basis of the laboratory of introduction and selection of flower plants of the South-Ural Botanical Garden-Institute of Ufa Federal Research Centre of Russian Academy of Sciences. The objects of the study were different ecological groups of plants in relation to water ‒ hydrophytes, mesophytes and xeromesophytes. The water deficit of leaves and accompanying characteristics (relative turgescence) were determined by saturation of plant samples according to methodological guidelines; water retention capacity, tissue hydration and the level of daily water loss were determined by artificial wilting. The obtained results characterize the peculiarities of the water regime of irises and indicate significant interspecific differences. It was revealed that the flora of the Republic of Bashkortostan contains plants both with a wide range of variability of water retention capacity (I. pumila) and with a fairly conservative one (I. pseudacorus, I. sibirica). Both strategies are successful in the continental climate of the Southern Urals. Introduced taxa of the subgenus Xyridion also keep to a particular strategy and it can be considered an indicator of successful introduction. It is shown that local species of irises do not form a water deficit in conditions of excessive moisture, while 6 taxa of the subgenus Xyridion have an average level of water deficit. According to the sum of indicators, the studied taxa belong to the groups with medium and high stability of the water regime due to low water deficit, high water retention capacity and hydration. These parameters are found in various combinations and sustain the stability of the water regime of cultivars. The studied physiological indicators can be used to assess the success of introduction in comparison with local control species.