QTL analysis of intraspecific differences between two Silene vulgaris ecotypes.
OBJECTIVE
Serpentine soils provide a highly selective substrate for plant colonization and growth and represent an ideal system for studying the evolution of plant-ecotypes. In the present study the aim was to identify the genetic architecture of morphological traits distinguishing serpentine and non-serpentine ecotypes of Silene vulgaris.


METHODS
Using an F(2) mapping population derived from an intraspecific cross between a serpentine and a non-serpentine ecotype of S. vulgaris, the genetic architecture of 12 morphological traits was explored using a quantitative trait locus (QTL) analysis.


RESULTS
The QTL analysis identified a total of 49 QTLs, of which 24 were classified as major QTLs. The mean number of QTLs per trait category was found to correspond well with numbers reported in the literature for similar crosses. Clustering of QTLs for different traits was found on several linkage groups.


CONCLUSIONS
Morphological traits that differentiate the two ecotypes are strongly correlated, presumably as a consequence of the joint effects of extensive linkage of QTLs for different traits and directional selection. The signature of consistent directional selection was found for leaf and shoot trait divergence. Intraspecific ecotype differences in S. vulgaris were found to be distributed across the entire genome. The study shows that QTL analyses on non-model organisms can provide novel insights into the genetic basis of plant diversification.
Bratteler
Martin
M
ETH Zurich, Institute of Integrative Biology, Plant Ecological Genetics, 8092 Zurich, Switzerland.
Baltisberger
Matthias
M
Widmer
Alex
A
D002874:Chromosome Mapping; D016000:Cluster Analysis; D035264:Flowers / Q000033:anatomy & histology; D018745:Genome, Plant; D008126:Lod Score; D018515:Plant Leaves / Q000033:anatomy & histology; D018520:Plant Shoots / Q000033:anatomy & histology; D040641:Quantitative Trait Loci; D029751:Silene / Q000033:anatomy & histology / Q000235:genetics*; D013045:Species Specificity