Overview
This research focuses on the candidate genes or genes potentially involved in the development of cell wall structures and tree wood properties. We aim to reduce the number of candidate genes down from several hundred to ten or fewer and then screen the reduced number in transgenic plants.
Contact Dr Phillip Wilcox
Candidate gene selection
The CBC is currently mapping candidate genes, or genes that show differential expression between juvenile and mature wood tissue, in our QTL mapping pedigree. Work is ongoing to map two of the genes identified as having alleles that appear to correlate to differences in juvenile wood density among trees. These gene sequences are found in other pine trees and even other plants and, if the genes are confirmed as determining wood density in pines, this could have implications beyond radiata pine tree improvement.
- Detection of quantitative trait loci (QTL) in radiata pine using DNA markers: 850.055 x 850.096 - small populations (90 - 600 genotypes), many traits; 268.405 x 268.345 - large population (~ 3000 genotypes total)
- Statistical procedures for QTL detection and associated genetics experiments, with an emphasis on Bayesian methods.
- Construction of framework linkage maps of Pinus radiata based on dominant and more recently, codominant markers.
- Design of QTL detection experiments: Sample sizes; Number of families; Criteria for choosing markers for selection; Detection vs selection.
Association Mapping
When markers are used to select desirable traits, the statistical correlations between marker alleles and phenotypic extremes of the trait are often established by analysing segregation data from controlled crosses. Such correlations are valid for a particular cross, but may not be valid for crosses between different individuals because linkage relationships among marker and trait alleles vary among individuals in an outcrossing population. It is possible to identify markers and gene sequences that are associated with trait variation in a population by using association tests to determine gametic or linkage disequilibrium
Contact: Dr Phillip Wilcox |