Influence of pine and oak litter on growth and mycorrhizal community structure of Scots pine seedlings in bare-root nursery condition

The effects of pine and oak forest litter on mycorrhizal status of 2−year−old Pinus sylvestris L. seedlings grown in a bare−root nursery was investigated. The research was carried out in the nursery of Vilnius University Botanical Garden in Lithuania. Ectomycorrhizal communities were assessed by a combination of morphological and molecular techniques. Statistical analysis revealed significant effect of litter treatment on some growth parameters of seedlings: seedling height, needle dry weight and total seedling weight. The survival rate of seedlings was significantly highest for oak litter, intermediate for pine litter, and lowest for control soil. Pine seedlings were colonized by indigenous ecto− and ectendomycorrhizal symbionts. Seven mycorrhizal species (Suillus luteus, S. variegatus, Wilcoxina mikolae, Tuber sp., Tomentella sp., Cenococcum geophilum, Amphinema byssoides) were distinguished on the roots of pine seedlings as well as one ectomycorrhizal symbiont not identified to species level. In total, 6 mycorrhizal types were found in control soil, 5 in pine litter, and 8 in oak litter. Suilloid (S. luteus and S. variegatus) and Wilcoxina mycorrhizae were dominant on tested seedlings, irrespective of litter addition. Seedlings grown in untreated nursery soil were 34% colonized by W. mikolae, while suilloid mycorrhizae were dominant after litter treatment (81% in pine litter and 63% in oak litter). We may conclude that suilloid mycorrhizae are better adapted to the conditions related to litter addition than W. mikolae

Genetic diversity of aquatic Ranunculus ( Batrachium, Ranunculaceae) in one river basin caused by hybridization

Aquatic Ranunculus (sect. Batrachium) include homophyllous and heterophyllous plants. The development of floating leaves may be induced by genetic mechanisms or/and environmental conditions and this fact complicates the morphologically based identification of species. DNA-based studies provide the opportunity to expand the knowledge of this complicated group. We studied heterophyllous Ranunculus with well-developed capillary and intermediate leaves and visually homophyllous plants with capillary leaves from a single river basin, with the aim to evaluate their genetic polymorphism and taxonomic status-whether the plants with well-developed and weakly expressed intermediate leaves belong to different forms (taxa) or if they just express morphological variation of one or two taxa in a specific, very variable river environment. The studied heterophyllous and homophyllous plants from different rivers showed high genetic differentiation and a low level of genetic diversity within these groups. The molecular analysis did not reveal any inter simple sequence repeat (ISSR) polymorphism associated with the development of intermediate leaves. An analysis of nuclear ribosomal internal transcribed spacers ITS1-2 sequences revealed several ribotypes, which indicated the genetic heterogeneity of studied plants and indirectly confirmed the hybrid origin of some of them. Sterile plants originated from crossing of R. circinatus and R. penicillatus were discovered in the Skroblus River; however, identification of the parental species was impeded by the polymorphism detected. For this reason, cytological studies were performed and allowed confirmation of the hybrid origin of these plants

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

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