Due to extensive selection pressure most modern crop cultivars display limited genetic variability, a fact that presents a significant barrier in crop improvement. To circumvent this problem there has been much recent effort to reintroduce genetic variability by crossing elite cultivars with exotic germplasm such as wild species and landraces. As a result collections of introgression and recombinant inbred lines (RILs) exist for the majority of the world's most important crops. Whilst these populations are characterized to varying levels of genetic resolution the availability of high-quality genetic maps facilitates their use in marker-assisted selection. When viewed from a horticultural perspective, these populations have arguably been most important in breeding for disease resistance as well as herbicide and salinity tolerance. That said the emergence of high-throughput phenotyping platforms such as transcriptomics, proteomics and metabolomics have facilitated biochemical and molecular analysis at a previously unprecedented level. Here we address the question posed by the title of this article by discussing the application of these methods both as tools to screen biodiversity and to establish quantitative trait loci for crop compositional traits.
- Marker-assisted selection