Extensive hybridization in Ranunculus section Batrachium (Ranunculaceae) in rivers of two postglacial landscapes of East Europe

We demonstrate a wide distribution and abundance of hybrids between the river species Ranunculus aquatilis, R. fluitans and R. kauffmannii with the still water species R. circinatus (Batrachium, Ranunculaceae) in rivers of two postglacial landscapes of East Europe, i.e., Lithuania and Central European Russia. The Batrachium species and hybrid diversity is higher in the rivers of Lithuania (4 species and 3 hybrids vs. 2 and 1) and represented mainly by western R. aquatilis, R. fluitans and their hybrids whereas in Central European Russia, the East European species R. kauffmannii and its hybrid are the only dominant forms. Hybrids make up about 3/4 of the studied individuals found in 3/4 of the studied river localities in Lithuania and 1/3 of the individuals found in 1/3 of the localities in Central European Russia. Such extensive hybridization in river Batrachium may have arisen due to the specificity of rivers as open-type ecosystems. It may have been intensified by the transformation of river ecosystems by human activities and the postglacial character of the studied landscapes combined with ongoing climate change. Almost all hybrids of R. aquatilis, R. fluitans and R. kauffmannii originated from unidirectional crossings in which R. circinatus acted as a pollen donor. Such crossings could be driven by higher frequency and abundance of R. circinatus populations as well as by some biological mechanisms. Two hybrids, R. circinatus × R. fluitans and R. circinatus × R. kauffmannii, were formally described as R. × redundans and R. × absconditus. We found a hybrid which most likely originated from additional crossing between R. aquatilis and R. circinatus × R. fluitans

Eco-genetic variation of development and adaptedness traits of seedlings of local scots pine populations in Lithuania

Reaction of progenies (seedlings) of different Scots pine (Pinus sylvestris L.) populations at the juvenile stage on new climatic and microclimatic conditions was investigated. Differences in the development and adaptation parameters of seedlings of three most distant according io conlinentally (Telšiai, Labanoras, Veisiejai) populations from different geographical regions of Lithuania were revealed and hcritabilily of these traits was established. By variance analysts, the influence of climalic and microclimatic conditions of the environment on the general variation of traits of the seedlings has been found out. Due to a greater trail genetic variation, the selection of families inside populations can be more effective than between populations. In favorable microclimatic conditions (in the greenhouse) variation of growth and biological productivity parameters o!' seedlings is higher, therefore selection would be more effective on population, family and individual levels. Seedlings of the most continental Labanoras population surpass the representatives of Telšiai population formed in the maritime conditions and the southern Veistejai population of medium conlinentally according to growth and biological productivity parameters. The Telsiai population was distinguished by slow growth and lower biological prodtictivily. The survival of seedlings of different populations decreases from the north to the south: the seedlings of Telšiai population formed in the maritime conditions according to this parameter have an advantage over the representatives of the most continental (Labanoras) ami medium continental (Veisiejai) populations. Different adaptation character of individual populations was observed. The general adaptation is typical of Labanoras population, because their progenies grow well in all regionsVytauto Didžiojo universitetasŽemės ūkio akademij

Response of Scots pine (Pinus sylvestris L.) seedlings to different climatic conditions and their adaptation peculiarities

Santr. angl., lietBibliogr.: p. 45-46(26 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij