Strong selection in wheat populations during ten generations of dynamic management

Goldringer, Isabelle; Enjalbert, Jérôme; Raquin, Anne-Laure; Brabant, Philippe

doi:10.1186/bf03500894

Cited by 39 publications

(29 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, we found that the dwarfing allele was associated with a reduction in fitness value because of between‐plant competition within the population, which led to the decrease in frequency over generations. This response illustrates the conflict between individual and group interests as described in a previous study on the same population (generations 1, 5 and 10, Goldringer et al . 2001), where negative within‐population correlations between plant height and number of kernel per plant were observed, together with positive between‐population correlation between the same traits.…”

Section: Discussionsupporting

confidence: 78%

“…In the entire genome. The mean genetic effective population size estimated between parents and G17, using the 21 loci located in the entire genome ( N eg = 167), was similar to the genetic effective population size estimated using restriction fragment length polymorphism (RFLP) markers at a previous generation (G10, N eg = 144) (Goldringer et al . 2001), but was smaller than the demographic effective population size ( N ed = 2625) based on a minimum of 5000 plants grown at each generation and corrected for the inbreeding coefficient. …”

supporting

confidence: 53%

“…On the other hand, theory (Santiago & Caballero 1995) and some experimental results (Austerlitz & Heyer 1998) showed that low levels of correlation between the effective family sizes for successive generations may strongly reduce genetic effective population size. This led us to conclude that significant and heritable differences in reproductive contribution of individuals due to selection on various multigenic traits, including plant height, were probably at the origin of this discrepancy, which has already been observed in the same population at earlier generations (Goldringer et al . 2001).…”

Section: Discussionmentioning

confidence: 60%

“…In the latter case, selection would increase the variance of reproductive contribution (indirect effect) while modifying the frequency of the genes involved in the control of the fitness‐related traits. In a previous study (Goldringer et al . 2001), using the analytical formulae (Caballero 1994) for the calculation of N eg in the case of nonherited variation in the reproductive contribution, we found that only unrealistic variances could explain the discrepancy we observed between the estimated N eg and the demographic size of the populations.…”

Section: Discussionmentioning

confidence: 87%

See 3 more Smart Citations

Soft selective sweep near a gene that increases plant height in wheat

Raquin¹,

Brabant²,

Rhoné³

et al. 2008

Molecular Ecology

View full text Add to dashboard Cite

Strong selection within a given population locally reduces genetic variability not only in the selected gene itself but also in neighbouring loci. This so-called hitch-hiking effect is related to the initial linkage disequilibrium between markers and the selected gene, and depends mainly on the number of copies of the beneficial allele at the start of the selection phase. Contrary to the classical case, in which selection acts on a single, newly arisen beneficial mutation, we considered selection from standing variation (soft selective sweeps) on a gene (Rht-B1) with a major effect on plant height, a selected trait in an experimental wheat population grown for 17 generations, and we documented the evolution of gene diversity and linkage disequilibrium near this gene. As expected, Rht-B1 was found to be under strong selection (s = 0.15) and its variation in frequency accounted for 15% of the total trait evolution. This led to a smaller genetic effective population size at Rht-B1 (N(eg) = 18) compared to the whole genome estimation (N(eg) = 167). When compared with expectations under genetic drift only, no significant decrease in gene diversity was found at the closest loci. We computed expected di-locus frequencies for any linked marker-Rht-B1 pair due to hitch-hiking effects. We found that hitch-hiking was expected to affect the two most closely linked loci, but expected reduction in gene diversity was not greater than that due to genetic drift, which was consistent with the observations. Such limited effect was attributed to the low level of linkage disequilibrium (0.16) estimated after parental intercrosses, together with a relatively high initial frequency of the gene. This situation is favourable to candidate gene approaches where small linkage disequilibrium around selected genes is expected.

show abstract

Section: Discussionsupporting

confidence: 78%

supporting

confidence: 53%

Section: Discussionmentioning

confidence: 60%

Section: Discussionmentioning

confidence: 87%

See 2 more Smart Citations

Soft selective sweep near a gene that increases plant height in wheat

Raquin¹,

Brabant²,

Rhoné³

et al. 2008

Molecular Ecology

View full text Add to dashboard Cite

show abstract

“…(1999). Estimating the expected level of differentiation for two divergent populations with a demographic size of 2650 individuals (5000 plants per populations corrected for the mean inbreeding coefficient α = 0.9, Goldringer et al . 2001) evolving under genetic drift only during 12 generations gave also a smaller value of genetic differentiation (θ = 1 – e −t/2N = 0.002; Hedrick 2005).…”

Section: Discussionmentioning

confidence: 99%

Insight into the genetic bases of climatic adaptation in experimentally evolving wheat populations

et al. 2008

Self Cite

View full text Add to dashboard Cite

Experimental populations evolving under natural selection represent an interesting tool to study genetic bases of adaptation. Evolution of genes possibly involved in adaptive response can be followed together with the corresponding phenotypic traits. Using experimental populations of hexaploid wheat, we studied the evolution of flowering time, a major adaptive trait that synchronizes the initiation of reproduction and the occurrence of favourable environmental conditions. During 12 generations, three populations were grown in contrasted environments (Vervins North France, Le Moulon near Paris, Toulouse South France) under the influence of natural selection, drift, mutation and recombination. Evolution of diversity at the major gene VRN-1 involved in wheat vernalization response has been analysed jointly with earliness estimated in controlled conditions. Whatever the population, rapid phenotypic changes as well as parallel genotypic variations were observed in the first seven generations, probably as the result of selection acting on this major gene which explains 80% of the trait variation overall. Different allelic combinations at physically unlinked copies of VRN-1 located on distinct genomes (A, B and D) were selected between populations. As theoretically expected, due to population differentiation, a high level of genetic diversity was maintained overall in generation 12. Surprisingly, in two populations out of three, the emergence of new alleles by mutation or migration, coupled with temporal variable selection or frequency-dependent selection, allowed to maintain within-population diversity despite local genetic drift and natural selection. This result may plead for an evolutionary approach of wheat genetic resource conservation.

show abstract

Breeding for Genetically Diverse Populations: Variety Mixtures and Evolutionary Populations

Dawson

Goldringer²

2011

Organic Crop Breeding

View full text Add to dashboard Cite

Strong selection in wheat populations during ten generations of dynamic management

Cited by 39 publications

References 16 publications

Soft selective sweep near a gene that increases plant height in wheat

Soft selective sweep near a gene that increases plant height in wheat

Insight into the genetic bases of climatic adaptation in experimentally evolving wheat populations

Breeding for Genetically Diverse Populations: Variety Mixtures and Evolutionary Populations

Contact Info

Product

Resources

About