Quantitative trait locus mapping of genes under selection across multiple years and sites in Avena barbata: epistasis, pleiotropy, and genotype-by-environment interactions

The genetic architecture of variation in evolutionary fitness determines the trajectory of adaptive change. We identified quantitative trait loci (QTL) affecting fitness in a mapping population of recombinant inbred lines (RILs) derived from a cross between moist- and dry- associated ecotypes of Ave...

Full description

Saved in:
Bibliographic Details
Published in:Genetics (Austin) 2010-05, Vol.185 (1), p.375-385
Main Authors: Latta, Robert G, Gardner, Kyle M, Staples, David A
Format: Article
Language:English
Subjects:
Alleles
Bayes Theorem
Chromosome Mapping
Environment
Epistasis, Genetic
Evolution
Evolution & development
Genetic Fitness
Genetic Linkage
Genotype
Genotype & phenotype
Investigations
Likelihood Functions
Models, Genetic
Poaceae - genetics
Quantitative Trait Loci - genetics
Selection, Genetic
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The genetic architecture of variation in evolutionary fitness determines the trajectory of adaptive change. We identified quantitative trait loci (QTL) affecting fitness in a mapping population of recombinant inbred lines (RILs) derived from a cross between moist- and dry- associated ecotypes of Avena barbata. We estimated fitness in 179 RILs in each of two natural environments in each of 4 years. Two loci account for over half of the variation in geometric mean fitness across environments. These loci are associated in repulsion phase in the wild ecotypes, suggesting the potential for strong transgressive segregation, but also show significant epistasis giving hybrid breakdown. This epistasis is the result of sharply lower fitness in only one of the recombinant genotypes, suggesting that the loci may contain synergistically acting mutations. Within each trial (year/site combination), we can explain less of the variation than for geometric mean fitness, but the two major loci are associated with variation in fitness in most environments. Tests for pleiotropic effects of QTL on fitness in different environments reveal that the same loci are under selection in all trials. Genotype-by-environment interactions are significant for some loci, but this reflects variation in the strength, not the direction of selection.
ISSN:1943-2631
0016-6731
1943-2631
DOI:10.1534/genetics.110.114389