| 1. |
- Boberg, Pelle, et al.
(författare)
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The effect of high temperatures on seed germination of one native and two introduced conifers in Patagonia
- 2010
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Ingår i: Nordic Journal of Botany. - Chichester : Wiley-Blackwell. - 0107-055X .- 1756-1051. ; 28:2, s. 231-239
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Tidskriftsartikel (refereegranskat)abstract
- We examined the effect of thermal shock on the germination of seeds of three conifers, two introduced (Pseudotsuga menziesii and Pinus ponderosa), and one native to Patagonia (Araucaria araucana). Previous research has suggested increased susceptibility to invasions in burnt areas, and therefore, the effect of simulated fire (heat) on seed germination in these native and introduced species was compared. Seeds were heated to two different heat intensities (50°C and 100°C) for 1 or 5 min, which is within the temperature range reached in the upper soil layers during forest fires. Germination tests were then carried out in a growth chamber. The heat treatments had a negative effect on the germination of P. menziesii at temperatures of 100°C, and a negative effect on the germination of P. ponderosa at the temperature of 100°C and the exposure of 5 min. The heat treatments had no affect at all on A. araucana. The species with larger seeds (A. araucana) had higher survival rates after the thermal shocks. Also intraspecific differences in seed sizes possibly point at larger seeds surviving thermal shocks better than smaller seeds. In addition, thermal shock caused a delay in the onset of germination in the two introduced species, while it did not change the time for germination in A. araucana. © The Authors. Journal compilation © Nordic Journal of Botany 2010.
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| 2. |
- Eneström, Johanna, et al.
(författare)
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Partitioning of genetic variation in the weedy clonal herb Aegopodium podagraria (Apiaceae) in Sweden
- 2009
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Ingår i: Nordic Journal of Botany. - Chichester : Wiley-Blackwell. - 0107-055X .- 1756-1051. ; 27:5, s. 437-443
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Tidskriftsartikel (refereegranskat)abstract
- Although sexual reproduction appears to be rare in many clonal plant species, the majority of clonal species show similar levels of genetic variation to non-clonal plant species. Aegopodium podagraria is a noxious garden weed and has become a successful invader in many natural habitats. Earlier studies have demonstrated population differentiation in life-history traits between different A. podagraria populations in Sweden. In this study, we used three methods to assess genetic variation in this species. Using analyses of molecular markers (chloroplast DNA PCR-RFLP and allozyme electrophoresis) we did not detect any variation between different A. podagraria clones. However, a multivariate analysis of leaflet shape in five populations from central Sweden revealed considerable variation both within and between populations. The variation found in leaflet shape is suggested to be genetically based because the leaves were collected from plants grown from seed under similar conditions in a common garden environment. These relatively high levels of variation within and between populations indicate that there is likely to be repeated seedling recruitment within established populations. © The Authors. Journal compilation.
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| 3. |
- Franzén, Markus, et al.
(författare)
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Seed set differs in relation to pollen and nectar foraging flower visitors in an insect-pollinated herb
- 2009
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Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 27:4, s. 274-283
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Tidskriftsartikel (refereegranskat)abstract
- Assessing the relative contributions to seed sets of each of a plant species' floral visitors provides an indication of the relative influence of these visitors on the plants' reproductive success. In this study we compared the seed set of the gynodioecious Knautia arvensis (Dipsacaceae) in 49 local plant populations in two regions of southern Sweden. We measured the seed set for hermaphroditic and female plant individuals. In both plant sexes and both regions, the seed set was positively related to the abundance of Apidae. The seed set was negatively related to the abundance of pollen-foraging solitary bees (Halictidae, Megachilidae) and beetles (Oedemeridae, Malachidae). The seed set was not related to plant population size, plant density or female frequency. Our results confirm that pollination success in generalised plant-pollinator systems varies between pollinator groups. Flower-visitors foraging for pollen might not contribute to increased pollination success in generalised pollination systems.
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| 4. |
- Hedrén, Mikael
(författare)
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Plastid DNA haplotype variation in Dactylorhiza incarnata (Orchidaceae): evidence for multiple independent colonization events into Scandinavia
- 2009
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Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 27:1, s. 69-80
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Tidskriftsartikel (refereegranskat)abstract
- The early marsh orchid, Dactylorhiza incarnata (L.) Soo s. l., grows in medium-rich to rich fens and marshes over much of Europe and parts of Asia. The species is highly polymorphic and different forms may grow together at the same site. In the present study, I tested the hypothesis that these forms represent different migrant populations that have colonized Scandinavia independently of each other, possibly from different source areas. Accessions from Scandinavia and elsewhere were screened for variation at three size-variable plastid marker loci, one polyA repeat, one polyA-polyTA-polyT repeat and one 9 bp indel. Ten haplotypes were defined on basis on the combined variation pattern. The common occurrence of several haplotypes in southern Scandinavia and adjacent areas to the south and the east of the Baltic Sea suggests that D. incarnata has been dispersed on repeated occasions across the Baltic. Also, there was some correlation between haplotype composition and morphological form on the island of Gotland, in agreement with the independent colonization hypothesis. Material from northernmost Sweden, Finland and northwest Russia was fixed for a single widespread haplotype, indicating that populations in this area are located farther away from the Pleistocene refugia. Dactylorhiza incarnata ssp. lobelii from southwest Norway was characterized by a haplotype that was not encountered elsewhere in Scandinavia. Given its proximity to British populations dominated by the same haplotype, it is suggested that D. incarnata ssp. lobelii was established independently of the other Scandinavian populations, from coastal refugia located in western Europe.
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| 5. |
- Jonsell, Bengt, et al.
(författare)
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Nomenclatural notes to Flora Nordica Vol. 6 (Thymelaeaceae-Apiaceae)
- 2009
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Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 27:2, s. 138-140
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Tidskriftsartikel (refereegranskat)abstract
- The following names in Flora Nordica Vol. 6 are subject to nomenclatural action: Helianthemum oelandicum var. canescens (typified), Epilobium hornemannii (typified), Oenothera nuda (validated), Myriophyllum spicatum (emendation of typification), Viola rupestris subsp. relicta (typified), Hippophae rhamnoides (typified), Angelica archangelica subsp. littoralis (typified). - Flora Nordica Note no. 35.
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| 6. |
- Kärnefelt, Ingvar
(författare)
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Editorial
- 2009
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Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 27:3, s. 165-165
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Tidskriftsartikel (refereegranskat)abstract
- Abstract is not available
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| 7. |
- Olofsson, Sofie, et al.
(författare)
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Evolution, phylogeography and taxonomy of allopolyploid Dactylorhiza (Orchidaceae) and its implications for conservation
- 2009
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Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 27:6, s. 548-556
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Tidskriftsartikel (refereegranskat)abstract
- This review is based on recent molecular studies of Dactylorhiza (Orchidaceae). Most of the studies have focused on the allotetraploid members of the genus in general and on D. majalis ssp. lapponica in particular. It was concluded that most of the allotetraploid taxa have derived from hybridizations between the parental lineages D. maculata s.l. and D. incarnata s.l., with D. maculata s.l. serving as the seed parent. Evidence of multiple origins was found both among northern European allotetraploids as well as among Greek allotetraploids. Introgression from both parental lineages and hybridizations between independently derived polyploid lineages was also detected. The three morphologically similar taxa D. majalis ssp. traunsteineri, ssp. lapponica and ssp. russowii should be treated as one and most of the Greek allotetraploids should be regarded as regional variants of the southeastern European D. majalis ssp. cordigera. The Balkans and the Alps most probably served as refugia for the genus during the last glaciations and at least two waves of immigration reached Scandinavia. Finally, we suggest that the conservation of allotetraploid Dactylorhiza should emphasize important geographic areas and habitats and that the allopolyploids should have the same conservation status as the diploids.
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| 8. |
- Pedersen, Henrik A. E., et al.
(författare)
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On the distinction of Dactylorhiza baltica and D-pardalina (Orchidaceae) and the systematic affinities of geographically intermediate populations
- 2010
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Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 28:1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- The eastern European Dactylorhiza baltica (Klinge) N. I. Orlova and the western European D. pardalina (Pugsl.) Aver. (= D. praetermissa var. junialis (Verm.) Sengh) are usually considered to have non-overlapping geographic distributions, for which reason it has rarely been realized that they are morphologically similar. They have not previously been thoroughly compared by molecular methods, and no existing flora or revision has convincingly demonstrated that they can be distinguished by morphological characters. In reality, they might be 'political' rather than natural taxa. Prompted by the recent discovery of geographically intermediate populations (in eastern Denmark), originally identified as D. baltica, we have addressed this problem by analysis of morphometric data as well as molecular data from allozyme markers, plastid haplotypes, nuclear ITS alleles and nuclear microsatellites. Dactylorhiza baltica and D. pardalina turned out to be clearly distinguished genetically, and although they are morphologically similar, a few characters were identified that distinguish with 81-85% certainty between the two taxa. Molecular and morphometric data place the geographically intermediate populations in D. pardalina. Both taxa were confirmed to be allotetraploids combining diploid genomes from the D. incarnata s.l. and D. maculata s.l. lineages, and they should therefore be recognized as infraspecic taxa under D. majalis s.l. Thus, D. baltica should be called D. majalis subsp. baltica; D. pardalina is identical with D. praetermissa var. junialis, but the nomenclatural consequences for D. praetermissa, if treated as subspecies under D. majalis, are still unresolved.
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| 9. |
- Ryde, Ulf
(författare)
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Genetic analysis shows that Rubus vikensis is a distinct species with a disjunct distribution
- 2010
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Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 28:2, s. 246-250
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Tidskriftsartikel (refereegranskat)abstract
- Rubus vikensis A. Pedersen ex G. Wendt (sect. Corylifolii) was recently described from a restricted area in north western Scania, Sweden. In this investigation, I show that the same species occurs also on the Onsala peninsula in northern Halland and on a single locality in the middle of Halland. It has 35 chromosomes in all parts of the distribution area. Moreover, I show by random amplified polymorphic DNA (RAPD) analysis that R. vikensis is a distinct and well-defined species, clearly separated from the morphologically similar R. wahlbergii, with which it shares the chromosome number.
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| 10. |
- Sandberg, Jakob, et al.
(författare)
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Despite high uptake efficiency, non-mycorrhizal Rumex acetosella increases available phosphorous in the rhizosphere soil, whereas Viscaria vulgaris, Plantago lanceolata and Achillea millefolium does not
- 2009
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Ingår i: Nordic Journal of Botany. - : John Wiley & Sons. - 0107-055X .- 1756-1051. ; 27:5, s. 444-448
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Tidskriftsartikel (refereegranskat)abstract
- The phosphorous (P) uptake efficiency, reduction of the soil extractable P, and the root morphology was determined for the four common grassland species Rumex acetosella, Viscaria vulgaris, Plantago lanceolata and Achillea millefolium in one pot cultivation and one microcosm experiment. Rumex acetosella produced more than tree times as much biomass as each of V. vulgaris, P. lanceolata and A. millefolium, and could maintain a P concentration in the tissue that was twice as high as in the other species. R. acetosella was able to take up 10 times more phosphorous than the other species but the high uptake was not reflected in reduced Olsen P levels in the root affected soil. Calculating the uptake efficiency of the roots with a diameter less than 0.5 mm showed that the P uptake, calculated per root area, had been more efficient in R. acetosella than in the other species. The calculated rhizosphere volume (explored by the plant) seemed to correlate with the higher uptake efficiency of R. acetosella. We can conclude that R. acetosella have mechanisms to maintain a high P availability in the soil and may sustain a high uptake without any mycorrhizal interactions.
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