RESUMO
Constituting one of Earth's major biomes, steppes are characterised by naturally treeless extra-tropical vegetation. The formation of the Eurasian steppe belt, the largest steppe region in the world, began in Central Asia during the Neogene. In the glacial stages of the Pleistocene, steppe displaced forest vegetation, which in turn recolonised the area during the warmer interglacial periods, thus affecting the distribution of plants adapted to these habitats. Krascheninnikovia ceratoides (Chenopodiaceae) is a plant characteristic of dry steppe and semi-desert formations. Earlier studies showed that the ancestor of this autochthonous steppe element originated in Central Asia during the Miocene/Pliocene, i.e., in the same region and at the same time as the first appearance of steppe vegetation. However, as the extant lineages of Krascheninnikovia ceratoides diversified only 2.2 ± 0.9 Mya, it may represent a modern element of current dry steppe and semi-desert formations, rather than a component of the first steppe precursors of the Miocene. As such, it may have capitalised on the climatic conditions of the cold stages of the Quaternary to expand its range and colonise suitable habitats outside of its area of origin. To test this hypothesis, phylogeographic methods were applied to high-resolution genotyping-by-sequencing data. Our results indicate that Krascheninnikovia originated in western Central Asia and the Russian Altai, then spread to Europe in the West, and reached North America in the East. The populations of eastern Central Asia and North America belong to the same clade and are genetically clearly distinct from the Euro-Siberian populations. Among the populations west of the Altai Mountains, the European populations are genetically distinct from all others, which could be the result of the separation of populations east and west of the Urals caused by the Pleistocene transgressions of the Caspian Sea.
RESUMO
This paper presents the results of the field study on species composition, geographical distribution, phytocoenotic diversity and resources of crop wild relatives (CWR) in Kazakhstan's ranges of the Tien Shan Mountains. Taxa of not only cultivated genera of crops are taken into account, but also a wider range of species of high socio-economic importance, including medicinal, fodder, essential oil and other species. List of CWR includes 289 species belonging to 39 families and 145 genera. Among them, 9 species listed in the Red Data book of Kazakhstan: Pistacia vera, Rheum wittrockii, Armeniaca vulgaris, Malus sieversii, Allium pskemense, Allochrusa gypsophilloides, Sorbus sibirica, Vitis vinifera and Artemisia cina. The highest plant diversity is recorded in intermountain plains and river valleys where meadow vegetation forms a high abundance of forage and resource plants. The diversity of wild fruit plants is concentrated in gallery forests. CWR of cereals are confined to dry steppe slopes in low piedmont belt. The populations of almond, pistachio, plum and cherry were recorded at dry slopes of low mountain belt. The estimation of the raw material base for 13 resource plants is given. Only Rumex tianschanicus, Berberis sphaerocarpa are recommended for industrial harvesting; for local pharmacy chain - Mentha longifolia, Origanum vulgare, O. vulgare subsp. gracile, Ziziphora clinopodioides, Hypericum scabrum, Hypericum perforatum, and five Rosa species.
