Chromosome numbers of wormwoods (Artemisia L.) from Central Kazakhstan

The subgenus Seriphidium (Besser. ex Less.) Fourr., which includes more than 100 species, is one of the largest subgenera within the genus Artemisia L. (Asteraceae Bercht. et J. Presl.). The aim of this work was to study the chromosome numbers of some wormwoods species of the subgenus Seriphidium to clarify their systematic position. The paper presents the chromosome numbers of 4 species (Artemisia turanica (Krasch.) Poljakov, A. juncea Kar. et Kir., A. terrae-albae Krasch., and A. semiarida (Krasch. et Lavrenko) Filatova) of the subgenus Seriphidium. The materialobjects of the study was mature seeds collected during field survey (2013-2016) in the territory of Central Kazakhstan (Karaganda Region, Ulytau District, Sarysu River valley, wormwood and hawthorn semi-desert) with 10 specimens of each species close in age. This study compares the literature data with the authors’ results of chromosome numbers. During the study, the chromosome numbers were determined for the first time for 2 wormwood species in the Kazakhstan population: A. juncea (2n=18) and A. turanica (2n=18). The obtained results show the homogeneity within the population of these species in the territory of Central Asia since for the Uzbekistan population, according to the data of Valles et al., A. turanica and A. juncea also have a diploid set of chromosomes. To clarify the systematic position and identify the intraspecific polymorphism of A. terrae-albae and A. semiarida, the morphological variability, geographical distribution, and chromosome numbers of these species were studied. Diploid and tetraploid sets of chromosomes were found in these species. The A. semiarida population has an exclusively diploid set of chromosomes (2n=18). According to the literature data for A. terrae-albae, a diploid set of chromosomes is given, but along with diploid individuals in the same region, we also found populations with tetraploid individuals (2n=36). The study of the morphological differences of these species made it possible to reveal that they differ only in quantitative traits (plant height, size of leaves and lateral branches) which depend on weather conditions. In years with a relatively high amount of precipitation, plants develop rather quickly, reaching larger sizes. The endemic species of Central Kazakhstan A. semiarida has an area that coincides with the area of A. terrae-albae. Populations of these species often grow together. Thus, the study of the morphological variability, chromosome numbers, and geographical distribution of these species made it possible to change the status of A. semiarida and consider it as a variety of the more widespread species A. terrae-albae, which can be represented by both diploid and tetraploid species. The papers contains 11 References. Acknowledgments: The authors express their deep gratitude and appreciation to Tatyana Ankova, Cand. Sci. (Biol.)ogycandidate of biological sciences, Rresearcher of the Herbarium laboratory (of the Central Siberian Botanical Garden, SB RAS, Novosibirsk) (Siberian Branch of the Russian Academy of Sciences), for help and opportunity to study chromosome numbers.

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