Evaluation of the ecological and genetic potential of Megadenia bardunovii Popov. (Brassicaceae) in the Tunkinsky National Park (Southern Siberia)
N. V. Kulakova1,2, T. V. Elisafenko3, E. R. Khadeeva4, S. G. Kazanovsky1, V. V. Murashko1, A. V. Verkhozina1
1Siberian Institute of Plant Physiology and Biochemistry of SB RAS, Irkutsk, Russia
2Irkutsk State University, Irkutsk, Russia
3Central Siberian Botanical Garden of SB RAS, Novosibirsk, Russia
4V. B. Sochava Institute of Geography of SB RAS, Irkutsk, Russia
Keywords: Megadenia, introduction, populations of Megadenia, relict, Tunkinskaya Valley, endemic plant species, phylogeny
Abstract
Rare endemic plant species are most sensitive to changes in ecosystems, which can negatively affect the state of populations. The study of various ecological parameters in natural locations is most important for their monitoring and conservation. Megadenia bardunovii is a relic species of the Tertiary period vegetation with a restricted area. In Russia, two small populations are known in the Tunka Valley (Republic of Buryatia). In this work, the composition of water and soil in the natural location, the area of populations, phylogenetic relationships were studied, an introduction experiment and seed reproduction assessment were carried out. The confinement of populations to freshwater springs and loose, fertile sod-carbonate soils was revealed. It was shown that the populations occupy an area of 408 and 564 mІ. Seed germination is low, vegetative reproduction predominates. Analysis of nuclear (ITS) and chloroplast (rbcL, matK, trnL-trnF, trnH-psbA) markers revealed the absence of genetic diversity in the two studied populations. Analysis of chloroplast DNA showed that the populations from the Tunka Valley represent a separate evolutionary lineage, significantly different from all other Megadenia populations in China and the Russian Far East. The introduction experiment showed that an adult individual is a perennial creeping-root polycarpic plant and consisting of a complex of rosette shoots formed from adventitious buds on roots. In the introduction experiment, the morphometric parameters of plants were close to those in situ. Under cultural conditions, the species is of medium promise for introduction and has average resistance during long-term cultivation; it does not withstand competition from other species. Biological features determine the species strategy - rapid capture of territory using adventitious buds on the roots. The studied populations can be characterized as relatively stable under existing conditions. The developing and maintenance of a reserve fund is relevant. The obtained results supplement the data on the ecology and biology of the species and determine the parameters for monitoring and preserving the species in natural habitats.
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