Abstract/Summary

The growth and yield of wheat is subject to constant attempts at improvement. Recent technology has allowed us to speed this process up by utilising genetic markers. Previous work has had to concentrate on small groups of traits at any one time due to the limited allelic representation in bi-parental populations. The aim of this project was to identify and study the genetic underpinnings of source and sink related traits in field conditions. The crop was measured throughout the full season to observe how these traits interact with each other continuously. To this end, the National Institute of Agricultural Botany (NIAB) eight-parent population was studied in two field seasons. The allelic diversity and high level of recombination present in this population gives us an unprecedented opportunity to identify novel Quantitative Trait Loci (QTL) that control varying aspects that impact the final yield. All traits measured exhibited a much greater range of diversity in the progeny compared to that of the founder lines. Using that diversity, we were able to identify QTL on every chromosome, with multiple major effect, stable, QTL occurring on 1B, 4B, 4D, 5A and 6A. Some of these have been described in previous literature, while others such as 1B appear to be novel. Further to this, there were two noteworthy QTL for yield that were not co-locating with any of the other measured traits. One of these QTL was stably located on 7B and explains on average 1.6% of the total phenotypic variation, while the other is located on 5B, explaining 6.02% of the total variation in a single environment.