Understanding genomic diversity and population structure of crop germplasm is important for germplasm conservation, cultivar development, and quantitative trait loci (QTL) mapping, and lays the foundation for genomics-assisted breeding [ 16, 17].
Breeders and molecular geneticists have routinely used populations derived from bi-parental crosses for variety development and mapping quantitative trait loci (QTLs) for traits of interest.
In this article, we describe the development of a quantitative trait loci (QTL) database and illustrate how it can be used to facilitate both the forward and reverse genetics research.
The development times of offspring from hybrid (between population) crosses were intermediate to offspring from pure-bred (within population) crosses in juvenile development times, indicating that development time is a quantitative trait (controlled by multiple loci, each of small effect) (Fig. 5, Table 3).
If offspring from hybrid (between population) crosses were intermediate to offspring from pure-bred (within population) crosses in juvenile development time, then we would conclude development time is a quantitative trait (controlled by multiple genes, each of small effect).
Distinguishing pleiotropy from linkage disequilibrium in such a species is difficult; one approach would be the development of a pleiotropic quantitative trait loci map of both traits, but such techniques are yet to be applied in wild passerine populations.
Keynote speaker Fred van Eeuwijk (Wageningen University) gave a comprehensive overview of genome × environment modeling in plants, from basic models taught in an introductory course for plant breeders, to recent developments incorporating temperature-responsive quantitative trait loci, and characterizing environments through additional variables such as temperature, rainfall, etc.
The locus-specific sequences obtained from PLUG markers are also potentially very useful for surveying sequence polymorphisms among wheat cultivars, allowing the development of new markers near quantitative trait loci (QTLs).
Identification of molecular markers for applying in a breeding programme requires the development of a genetic map and quantitative trait locus (QTL) analysis.
The development of reduced panels for any quantitative trait in breeds other than Angus is currently limited by the lack of training populations.
