The aim of this project is to flow sort, sequence and analyse wheat chromosome 4A for a NIL pair extracted from the NIAB MAGIC population and differing by presence of a Robigus-derived introgression, to establish the most likely candidates responsible for phenotypic effects observed to be caused by the introgressions.
Incorporating genes from wild relatives has played a major role in the breeding of modern wheat varieties. In particular, many important disease resistance and yield enhancing genes have been successfully transferred from wild grass species into the cultivated wheat gene pool. Historically this process has been rather haphazard, achieved via the process of wide crossing and phenotypic selection in breeding populations. As a result, deleterious traits, such as disease susceptibilities are often also brought in together with the positive genes. The advantages (and disadvantages) of unintended transfers often only become apparent late in the breeding process making it difficult to precisely target them. Modern genomic technology offers the potential to refine this process by locating and disentangling the specific genes carried over in these introgressions in order that they can be used to accelerate breeding in a targeted manner. In particular we are interested in the genomic composition of variety Robigus, which carries introgressions from the wild species Triticum dicoccoides. Robigus has played a major role in the pedigrees of modern wheat varieties, bringing in a suite of four disease resistances, as well as yield enhancements, although also carrying some deleterious genes. Robigus is a major component of UK wheat varieties (see below), and its progeny include the variety Oakley, which is the focus of TB’s PhD, another significant variety.
NIAB have developed a highly recombined, diverse Multi-parent Advanced Generation InterCross (MAGIC) population (Mackay et al., 2014). From the NIAB 8-parent MAGIC population, 6 major introgressions have been found in the modern UK wheat genepool and we have generated pairs of near-isogenic lines (NILs) which differ only at these introgressions. Two of these introgressions have come from the variety Robigus. Our preliminary work shows favourable phenotypes associated with the two Robigus introgressions and partners in France (INRA; Arvalis) have also identified a previously unknown “Robigus-effect” for nitrogen deficiency tolerance, which is hypothesised to be located on one of these introgressions.
The aim of this project is to flow sort (via an in-kind collaboration with Dr Jaroslav Dolezel at the Centre of Plant Structural and Functional Genomics, Czech Republic) and then sequence (using the requested OpenPlant funds) wheat chromosome 4A for a NIL pair extracted from the NIAB MAGIC population and differing by presence of a Robigus-derived introgression. A thorough bioinformatic analysis will then enable characterization of the genes present in the introgressions, and establish the most likely candidates responsible for the phenotypic effects observed to be caused by the introgressions. As well as establishing the mechanistic basis of many important traits, this analysis will enable us to develop the tools to track and maintain the beneficial genes in the modern gene pool, while eliminating the detrimental genes. We anticipate it may also enable us to identify novel targets for CRISPR/Cas9 gene-editing.
Mr Tobias Barber,
Graduate student, NIAB and Cambridge University
Dr Alison Bentley,
Director of Genetics and Breeding at NIAB, Cambridge
Dr Keith Gardner,
Statistical geneticist at NIAB, Cambridge
Dr Chris Wright,
Customer Liason Officer, Platforms and Pipelines, Earlham Institute, Norwich
Prof Jaroslav Dolezel,
Head of Centre of Plant Structural and Functional Genomics, Czech Republic
This project is due to report in 2018.