Change search
ReferencesLink to record
Permanent link

Direct link
Adaptive population differentiation across Europe in the perennial herb Lythrum salicaria.
Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
Article in journal (Refereed) Submitted
URN: urn:nbn:se:umu:diva-4245OAI: diva2:143256
Available from: 2004-11-12 Created: 2004-11-12Bibliographically approved
In thesis
1. Population differentiation in Lythrum salicaria along a latitudinal gradient
Open this publication in new window or tab >>Population differentiation in Lythrum salicaria along a latitudinal gradient
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In this thesis, quantitative genetic approaches, common-garden experiments, and field studies were combined to examine patterns of population differentiation and the genetic architecture of characters of putative adaptive significance in the widely distributed perennial herb Lythrum salicaria. In this work, I (1) documented patterns of population differentiation in phenology, life-history, and morphology along latitudinal gradients at different geographical scales, (2) investigated the genetic architecture of phenology, flower morphology, and inflorescence size, and (3) combined estimates of phenotypic selection in the field with information on the genetic variance-covariance matrix (G) to examine potential constraints to adaptive evolution.

A common-garden experiment demonstrated latitudinal variation in life-history, and phenology of growth and reproduction among L. salicaria populations sampled across Sweden. Flower morphology varied significantly among populations, but was, with the exception of calyx length, not related to latitude of origin. A second experiment, which included two Swedish, two Dutch, and two Spanish populations, indicated that the latitudinal gradient in reproductive and vegetative phenology might extend throughout Europe.

A quantitative-genetic study of two Swedish populations revealed significant additive genetic variation for all phenological and morphological traits investigated. The G matrices of the populations differed significantly according to common principal component analysis, and genetic correlations within the study populations did not strictly correspond to trait correlations observed among populations.

In a field study, I detected directional selection through female function for larger inflorescences in two consecutive years. Relative fitness increased disproportionately with inflorescence size in the year when supplemental hand-pollination indicated that pollen limitation was severe. Genetic correlations with inflorescence size considerably influenced predicted response to selection in other characters.

Taken together, the results suggest that among-population differences in phenology and life-history in L. salicaria have evolved in response to latitudinal variation in length of the growing season. They demonstrate that the evolutionary potential of local populations may be considerable. The genetic covariance structure substantially influences predicted short-term evolutionary trajectories. However, the weak correspondence between genetic correlations documented within populations and trait correlations among populations, suggest that the G matrix has not imposed strict constraints on patterns of among-population differentiation.

25 p.
Ecology, additive genetic variance, clinal variation, evolutionary constraints, G matrix, genetic correlation, natural selection, pollen limitation, population differentiation, Ekologi
National Category
Research subject
Ecological Botany
urn:nbn:se:umu:diva-364 (URN)91-7305-716-9 (ISBN)
Public defence
2004-12-11, Stora Hörsalen, KBC, Umeå, 10:00
Available from: 2004-11-12 Created: 2004-11-12Bibliographically approved

Open Access in DiVA

No full text

By organisation
Ecology and Environmental Science

Search outside of DiVA

GoogleGoogle Scholar
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

Total: 20 hits
ReferencesLink to record
Permanent link

Direct link