An investigation of the embryology of Potentilla nivea was carried out using a confocal laser scanning microscope. The crassinucellate nature of the ovule as well as the presence of a multicellular archesporium was confirmed. A "nucellar cap" builds up as the result of mitotic divisions in the parietal cell tissue and the nucellar epidermis. Earlier reports that several mature megagametophytes ...

Little information is available on gene expression profiling of halophyte A. canescens. To elucidate the molecular mechanism for stress tolerance in A. canescens, a full-length complementary DNA library was generated from A. canescens exposed to 400 mM NaCl, and provided 343 high-quality ESTs. In an evaluation of 343 valid EST sequences in the cDNA library, 197 unigenes were assembled, among wh...

Potential events of allopolyploidy may be indicated by incongruences between separate phylogenies based on plastid and nuclear gene sequences. We sequenced two plastid regions and two nuclear ribosomal regions for 34 ingroup taxa in Fragariinae (Rosaceae), and six outgroup taxa. We found five well supported incongruences that might indicate allopolyploidy events. The incongruences involved Apha...

Potentilla L. (Rosaceae) species have been used in traditional medicine in Asia, Europe and Northern America. This study analyzed the biological activity of aqueous extracts of Potentilla species (Rosaceae): Dasiphora fruticosa (syn. P. fruticosa), P. norvegica, P. pensylvanica, P. thuringiaca, P. crantzii and P. nepalensis. The activities were tested using MTT, NR and DPPH assays on normal hum...

The occurrence of arbuscular mycorrhizal (AM) fungi was surveyed along a latitudinal gradient in Arctic Canada including Banks Island (73°N), Devon Island (74°N), Ellesmere Island (76°N), and the Magnetic North Pole at Ellef Ringnes Island (78°N). At Banks Island, AM fungi were present and colonized at a high intensity in all specimens of Potentilla hookeriana Lehm. – Potentilla pulchella R.Br....

Phytoremediation potentials of four poplar lines, Populus nigra (N-SL clone), Populus canescens, and two transgenic P. canescens clones were investigated using in vitro leaf discs cultures. The transgenic poplars overexpressed a bacterial gene encoding gamma-glutamylcysteine synthetase in the cytosol (11ggs) or in the chlopoplasts (6LgI), and therefore, they contained an elevated level of gluta...

Evidence suggests that belowground self-recognition in clonal plants can be disrupted between sister ramets by the loss of connections or long distances within a genet. However, these results may be confounded by severing connections between ramets in the setups. Using Potentilla reptans, we examined severance effects in a setup that grew ramet pairs with connections either intact or severed. W...

Lundberg, M., 2011. Systematics and polyploid evolution in Potentilleae (Rosaceae). This thesis comprises studies of the phylogenetic relationships in the flowering plant clade Potentilleae in Rosaceae. The relationships were elucidated by using DNA sequence data from the nuclear genome as well as from the plastid genome. In particular, the focus of the studies was the investigation of allopoly...