Publishing House SB RAS:

Publishing House SB RAS:

Address of the Publishing House SB RAS:
Morskoy pr. 2, 630090 Novosibirsk, Russia



Advanced Search

Contemporary Problems of Ecology

2018 year, number 6

Morphological Adaptation of Thymus Species (Lamiaceae) in Yakutia

E. B. TALOVSKAYA, V. A. CHERYOMUSHKINA, G. R. DENISOVA
Сentral Siberian Botanical Garden, SB RAS, 630090, Novosibirsk, Zolotodolinskaya str., 101
Keywords: Thymus, адаптация, экотоп, морфогенез, Якутия, adaptation, ecotope, morphogenesis, Yakutia

Abstract

The diversity of life forms, the structure of individuals and ontomorphogenesis of T. extremus , T. indigirkensis , T. breviрetiolatus and T. pavlovii under the conditions of Yakutia have been studied. It has been established that the formation of two life forms and three types of biomorphs is characteristic of the species: a monocentric vegetatively-immobile dwarf subshrub ( T. extremus ), an implicitly polycentric vegetatively-semimobile dwarf subshrub and dwarf shrub ( T. indigirkensis and T. breviрetiolatus, respectively), obviously polycentric vegetatively-mobile dwarf subshrub ( T. pavlovii ). The basis of the adult bush is a monopodially-sympodially growing compound skeletal axis which differs in thyme specimens by the method of growth and position in space. An analysis of the development of species in Yakutia made it possible to identify common and specific features. Common features for species are the predominance of the dwarf subshrub living form and its morphological plasticity, a small diversity and shortening of the morphogenesis phases, a shallow rejuvenation of the ramet, a prolonged monopodial growth of shoots (up to 10 years), and the predominance of rosette shoots in the structure of the individual. Differences are revealed depending on the conditions of specific habitats of species. When T. extremus grows on a flat surface and high sludge, a dense primary shrub is formed. In the free areas of the substrate with stepwise depressions of the microrelief - the primary shrub of T. extremus is loose. In T. breviрetiolatus , which grows in the steppe on the hillside, the structure of the individual is formed only by rosette shoots, their prolonged monopodial growth is maintained due to the preservation (for 1-2 years) of dry leaves. For T. pavlovii , growing on a mossy substrate, it is characteristic lodging of shoots, their intensive rooting and strengthening of vegetative mobility, reduction of the duration of ontogenesis of individuals due to rapid decay of maternal structures. The revealed features of thyme development are the mechanisms of morphological adaptation which provide species survival in different environmental conditions of Yakutia.