liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Variation within species and inter-species comparison of seed dormancy and germination of four annual Lamium species
Linköping University, Department of Physics, Chemistry and Biology, Ecology . Linköping University, The Institute of Technology.
Linköping University, Department of Physics, Chemistry and Biology, Ecology . Linköping University, The Institute of Technology.ORCID iD: 0000-0001-6128-1051
2008 (English)In: Flora: Morphologie, Geobotanik, Oekophysiologie, ISSN 0367-2530, Vol. 203, no 5, 409-420 p.Article in journal (Refereed) Published
Abstract [en]

In an ecological context, knowledge of intra-species variation in dormancy and germination is necessary both for practical and theoretical reasons. We used four or five seed batches (replicates) of four closely related annuals co-occurring in arable fields in Sweden: Lamium amplexicaule, L. confertum, L. hybridum and L. purpureum. Seeds used for experiments stemmed from plants cultivated on two sites, each site harbouring one population of each species, thereby ensuring similar environmental history of seeds. Seeds were tested for germination when fresh and after three different pre-treatments (cold or warm stratification, or dry storage) for up to 24 weeks. Seeds were also sown outdoors. Despite substantial intra-species variation, there were clear differences between species. The general seed dormancy pattern, i.e. which environmental circumstances that affect dormancy, was similar for all species; dormancy reduction occurred during warm stratification or dry storage. Even though the response to warm stratification indicate a winter annual pattern, successful plants in Sweden were mostly spring emerged. Germination in autumn occurred, but plants survived winters poorly. Consequently, as cold stratification did not reduce dormancy, strong dormancy in combination with dormancy reduction during dry periods might explain spring germination. It is hypothesized that local adaptations occur through changes mainly in dormancy strength, i.e. how much effort that is needed to reduce dormancy; strong dormancy restrict the part of each seed batch that germinate during autumn, and thus risk winter mortality, in Sweden.

Place, publisher, year, edition, pages
Institutionen för fysik, kemi och biologi , 2008. Vol. 203, no 5, 409-420 p.
Keyword [en]
Deadnettle, Lamiaceae, phenology, physiological dormancy, summer annual, winter annual
National Category
Natural Sciences
URN: urn:nbn:se:liu:diva-11806DOI: 10.1016/j.flora.2007.08.001OAI: diva2:18228
Original publication: Laila M. Karlsson and Per Milberg, Variation within species and inter-species comparison of seed dormancy and germination of four annual Lamium species, 2008, Flora, (203), 5, 409-420. Copyright: Elsevier B.V., from: 2008-05-22 Created: 2008-05-22 Last updated: 2014-10-08
In thesis
1. Seed dormancy and germination in an ecological context: comparative studies of annual weeds
Open this publication in new window or tab >>Seed dormancy and germination in an ecological context: comparative studies of annual weeds
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [da]

Germination ecology studies, i.e. studies of interactions between characteristics of the seeds and environmental circumstances, provide understanding of spatial and temporal patterns of emergence of wild species, as weeds in the field. A large number of species have seed dormancy, i.e. seeds respond to circumstances not directly evoking germination. Thus, germination may occur only if specific environmental events have occurred in the seeds' past life story, and/or if a suitable time period has passed since ripening on mother plants. In this thesis, three characteristics, i.e. dormancy pattern, germination preferences and dormancy strength, hypothesised as mutually independent seed characteristics, are used to describe dormancy and germination in an ecological context. This conceptual model may be used for descriptions of differences between species, to understand emergence patterns in the field from controlled germination tests, and probably for increasing the understanding of evolution of ecological important properties of seed dormancy and germination.

Fifteen annual weedy taxa were investigated: two groups of temperate climate weeds, Lamium and Papaver, and one group of tropical weeds, co-occurring Asteraceae species of different genera. Intra-species variations in germination occurred for all species, but species-specific germination responses within all groups were revealed in analyses. All species showed some kind of species-specific dormancy pattern that was expressed as increased germination in response to one or more environmental factor not required for the actual germination.

For Lamium and Papaver, the general dormancy pattern was genus-specific. Germination preferences varied slightly within genus. Dormancy strength was to some extent species-specific, but highly variable. The species belonging to Asteraceae showed differences in dormancy pattern. It is shown how such differences can be visualized and compared by plotting response time and achieved germination in two-dimensional graphs, giving species-specific pictures.

Dormancy pattern and germination preferences explained how Papaver can perform as winter annuals in warmer climates, but substantially as summer annuals in colder climates, without local adaptations. For Lamium, the results indicate a local adaptation of increasing dormancy strength: in relatively cold climate in Sweden, a strong dormancy restricted a part of each cohort from germinating during autumn, thus preventing from winter mortality. For the Asteraceae, five of six species clearly responded to cold pretreatment, which is noteworthy considering the small seasonal temperature differences in the study area and in the areas of origin for the species. The six Asteraceae achieved similar emergence timing in the field by responding to different environmental factors.

Together, the results from these fifteen species indicate that dormancy pattern is an evolutionary conservative characteristic, dormancy strength is relatively easily changed, and germination preference is intermediate.

Place, publisher, year, edition, pages
Institutionen för fysik, kemi och biologi, 2007. 56 p.
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1088
Asteraceae, Bidens, Compositae, deadnettle, Galinsoga, germination timing, Guizotia, evolution, Labiatae, Lamiaceae, Lamium, morphophysiological dormancy, Papaveraceae, Papaver, Parthenium, physiological dormancy, poppy, summer annual, Tagetes, Verbesina, winter annual
National Category
Biological Sciences
urn:nbn:se:liu:diva-11444 (URN)978-91-85715-29-9 (ISBN)
Public defence
2007-04-17, Planck, Fysikhuset, Campus Valla, Linköpings universitet, Linköping, 09:30 (English)
Available from: 2008-04-03 Created: 2008-04-03 Last updated: 2014-10-08

Open Access in DiVA

fulltext(307 kB)573 downloads
File information
File name FULLTEXT01.pdfFile size 307 kBChecksum SHA-1
Type fulltextMimetype application/pdf

Other links

Publisher's full textLink to Ph.D. Thesis

Search in DiVA

By author/editor
Karlsson, LailaMilberg, Per
By organisation
Ecology The Institute of Technology
In the same journal
Flora: Morphologie, Geobotanik, Oekophysiologie
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 573 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 196 hits
ReferencesLink to record
Permanent link

Direct link