+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Estimating the extent of natural selection in seedlings from different Fagus sylvatica (L.) populations: application of new measures

Journal of Heredity 85(3): 183-190

Estimating the extent of natural selection in seedlings from different Fagus sylvatica (L.) populations: application of new measures

Measures of the extent of viability selection are developed for the purpose of understanding significant frequency changes observed between the seed and the seedling stages at three isoenzyme gene loci in three populations of beech. These measures explicitly consider dependence of the realized extent of selection on the frequency distribution of genotypes prior to selection, overall reduction in population size, and lower and upper bounds set to selection by this reduction. Using a suitable measure of distance between frequency distributions, it turned out that the overall selective reduction in population size equals the selection load and that this load specifies the maximum feasible amount of selection. Application of the measures to the data provided the means to discuss associated and operative effects of selection in an attempt to explain the frequency changes observed at the isoenzyme loci. The observations suggest associated selection as a major force of frequency dynamics of genetic types. This helps resolve the dilemma resulting from the expectation of excessive selection load for selection at many loci. A likely cause of persistent stochastic associations among loci--the small reproductively effective subpopulations that vary across breeding seasons--are discussed; these are probably typical of long-lived, iteroparous organisms. There is evidence that, across all populations, some loci tend to evolve stochastic independence from the respective operative genetic background more readily than others; this could be explained by only occasional occurrence of operative selection episodes at these loci. Reprinted by permission of the publisher. .

Accession: 002373012

Related references

Tognetti, R.; Johnson, J.D.; Michelozzi, M., 1995: The response of European beech (Fagus sylvatica L.) seedlings from two Italian populations to drought and recovery. The response of gas exchange, leaf chlorophyll content, relative fluorescence to decreasing water potential and recovery was followed in European beech (Fagus sylvatica) seedlings from two Italian populations. A population from Sicily (southern It...

Cocozza, C.; de Miguel, M.; Pšidová, E.; Ditmarová, L'ubica.; Marino, S.; Maiuro, L.; Alvino, A.; Czajkowski, T.; Bolte, A.; Tognetti, R., 2016: Variation in Ecophysiological Traits and Drought Tolerance of Beech (Fagus sylvatica L.) Seedlings from Different Populations. Frequency and intensity of heat waves and drought events are expected to increase in Europe due to climate change. European beech (Fagus sylvatica L.) is one of the most important native tree species in Europe. Beech populations originating throug...

Genet, P.; Prevost, A.; Pargney, J.C., 2000: Seasonal variations of symbiotic ultrastructure and relationships of two natural ectomycorrhizae of beech (Fagus sylvatica/Lactarius blennius var. viridis and Fagus sylvatica/Lactarius subdulcis). Studies were carried out over 18 months in the litter soil of natural stands of 80- to 100-year-old beech trees in the Foret de Haye, Nancy, France, on the mycorrhizal associations between and L. blennius var. viridis and L. subdulcis. The occurre...

Starke, R.; Ziehe, M.; Muller Starck, G., 1996: Viability selection in juvenile populations of European beech (Fagus sylvatica L.). Changes of genetic structures among seedlings of European beech were studied under non-manipulated and ameliorated site conditions. Genotypic structures were compared between 2 different stages, pre-germinated seed nuts and surviving juvenile plan...

Ernst, D.; Liegl, I.; Kiefer, E.; Seidlitz, H.K.; Heller, W.; Sandermann, H.J., 2001: Early changes in mRNA populations in leaves of ultraviolet-B-treated European beech (Fagus sylvatica L.) seedlings. Changes in the patterns of gene expression were analysed in ultraviolet-B (UV-B; 280-320 nm)-treated seedlings of European beech (F. sylvatica) by differential display reverse transcriptase polymerase chain reaction (DDRT-PCR) of mRNA. Utilizing 1...

Bolte, A.; Czajkowski, T.; Cocozza, C.; Tognetti, R.; de Miguel, M.; Pšidová, E.; Ditmarová, Ĺubica.; Dinca, L.; Delzon, S.; Cochard, Hè.; Ræbild, A.; de Luis, M.; Cvjetkovic, B.; Heiri, C.; Müller, Jürgen., 2016: Desiccation and Mortality Dynamics in Seedlings of Different European Beech (Fagus sylvatica L.) Populations under Extreme Drought Conditions. European beech (Fagus sylvatica L., hereafter beech), one of the major native tree species in Europe, is known to be drought sensitive. Thus, the identification of critical thresholds of drought impact intensity and duration are of high interest f...

Merzeau, D.; Comps, B.; Thiebaut, B.; Letouzey, J., 1994: Estimation of Fagus sylvatica L mating system parameters in natural populations. The mating system of beech (Fagus sylvatica L) was investigated using polymorphism at 4 allozyme loci and the multilocus model of Ritland and Jain (1981). Beech appears to be a highly outcrossing species: the outcrossing rate ranges from 0.94 to 1...

Rossi, P.; Vendramin, G.G.useppe; Giannini, R., 1996: Estimation of mating system parameters in two Italian natural populations of Fagus sylvatica. Mating system parameters were estimated in two Italian natural populations of European beech (Fagus sylvatica L.) using a mixed mating model and considering seven allozyme loci (Idh-A, Lap-A, Mdh-B, Pgd-A, Pgd-B, Pgd-C, Skd-A). High values of mult...

Kunstler, G.; Curt, T.; Lepart, J., 2004: Spatial pattern of beech (Fagus sylvatica L.) and oak (Quercus pubescens Mill.) seedlings in natural pine (Pinus sylvestris L.) woodlands. Spatial pattern of recruitment is an important factor influencing population dynamics of plant communities. The spatial pattern is determined by seed dispersal and by the spatial variability of germination and initial survival. In the process of f...

Madsen, P., 1995: Effects of seedbed type on wintering of beech nuts (Fagus sylvatica) and deer impact on sprouting seedlings in natural regeneration. Natural regeneration of beech (Fagus sylvatica) is often initiated by soil preparation before seed fall in the mast years. The wintering of beech nuts and the sprouting of beech seedlings in mixed and mineral soil seedbeds (some of which were fenc...