Morphological Analysis of the Genus Lilium (Liliaceae) in the Northern Forest Steppe of Western Siberia

Abstract

Due to anthropogenic load there is a risk of area reduction of Siberian and Far Eastern species of lilies. One of the methods for preserving the native natural gene pool of Lilium is their cultivation ex situ. The research purpose involved analysis of the biomorphological features of the representatives of the genus Lilium L. in the conditions of the northern forest steppe of Western Siberia. The results of morphobiological features evaluation were obtained for the following species: L. pilosiusculum, L. regale, L. pumilum, L. pensylvanicum, L. callosum. Time of flowering and sum of positive temperatures (above 0 degrees C), effective temperatures (above +5 degrees C) and active temperatures (above +10 degrees C) were determined. They are necessary for the onset of developmental phenophases such as regrowth, budding, flowering and fruiting. The beginning of regrowth of L. pilosiusculum, L. regale, L. pumilum, L. pensylvanicum and L. callosum occurred in the first or second decades of May. Flowering started at different times: from the third decade of June to the third decade of July - L. pumilum; in June - L. pensylvanicum; from the second decade of July to the second decade of August - L. callosum; from the third decade of July to the first decade of August L. pilosiusculum; from the third decade of July to the second decade of August - L. regale. The criterion for the onset of species flowering is the sum of active temperatures typical for the region. There is a different ability of the species to fruiting, depending on hydrothermal conditions of the vegetation period. The results showed that the local flora species L. pilosiusculum had the maximum height of shoot reached more than 100 cm; while L. callosum, L. pumilum, L. pensylvanicum and L. regale had stunted shoots (less than 60 cm). L. pilosiusculum and L. regale had the maximum number of flowers in inflorescence and indicators of flower productivity. The indicator role of the main pigments of the photosynthetic apparatus (chlorophylls a and b, carotenoids) in the leaves during seasonal development was established for the first time. It was found that the most significant indicators of the physiological state of plants were the content of chlorophyll a and b, and carotenoids in the leaves. Their amount depended on the phenological phases of development. During budding, the carotenoid content increased, the concentration of chlorophyll a was greater than the concentration of chlorophyll b at all vegetation phases, the ratio between chlorophyll a and b was within the normal limits and ranged from 2.189 to 3.225 mg/g of raw weight, the value of a+b/carotenoids in species decreased by the time of fruiting. The determined changes in the pigment complex composition can be considered as indicators of the adaptation mechanism of species to environmental conditions. The obtained results are necessary for the rational use of lilies in the reintroduction work, the development of which is especially important in Siberia.