AAFC IWYP Aligned Call: Increasing Wheat Yield with Multi-omics

Wheat yield gains have averaged an annualized 1.14% increase worldwide from 1991 to 2012. However, considering FAO projections that indicate the world population will exceed 9 billion in 2050, this incremental development in a basic foodstuff needs to improve dramatically. As part of the effort to improve wheat yields the International Wheat Yield Partnership has the goal of increasing wheat yields by 50% in the next 20 years. Two key protagonists in this global wheat breeding effort are Canada and the UK where research institutions are working to achieve this goal.

It is recognised that this will require not only the development of new ideas and innovative approaches to discover new alleles and traits that underlie yield gains, but also dedicated breeding efforts to incorporate the traits into elite genetic backgrounds. Yield gains are not realized until they are delivered as finished cultivars into the hands of growers.

Wheat breeding programmes driven by traditional, phenotypic, selection accumulate favourable alleles and develop cultivars that result in high and stable yield in the given target environment. In wheat breeding, the necessity to develop cultivars with very specific end use quality targets increases the tendency to limit breeding work to elite-by-elite crossing, which consequently leads to a narrowing of the genetic background. Except for disease resistance alleles, which are often specifically targeted for the development of new cultivars, relatively little effort is typically incurred to broaden the genetic diversity of breeding programmes in order to discover under-utilized or novel alleles for agronomic performance and yield. This project proposes to share germplasm with a range of yield potentials and test cross diverse wheat growing environments.

By sharing genetic improvements between diverse breeding programmes, a foundation for the delivery of increased wheat yield in the form of new spring and winter wheat cultivars can be laid. Improvements in wheat yields can provide considerable return on investment for wheat producers. For example, a 5% increase in Canadian wheat production would have a farm gate value of approximately $300 million dollars ($CDN) for the Canadian economy.

The International Wheat Yield Partnership has a goal of increasing wheat yields by 50% in the next 20 years to meet future population growth. Traditionally, wheat breeding programmes, driven by phenotypic selection, accumulate favourable alleles and develop haplotypes that result in high and stable yield in the given target environment. In wheat breeding, the necessity to develop cultivars with very specific end use quality targets increases the tendency to limit breeding work to elite by elite crossing and consequently a narrowing genetic background. Except for disease resistance alleles, which are often specifically targeted for introgression, relatively little effort is typically diverted from elite breeding material to broaden the genetic diversity of a breeding programme to discover under utilized or novel alleles for agronomic performance and yield.

Here the goal is to share germplasm with a range of yield potentials and test across diverse wheat growing environments. This will be coupled with detailed phenotyping. Germplasm panels of winter and spring wheat with diverse yield potential will be characterized by high density genotyping and will be grown at multiple locations in Canada and England. The spring and winter wheat germplasm panels will be evaluated using traditional and phenomics-based approaches to identify traits for increased biomass, increased carbon capture, delayed senescence, improvement of yield related traits, such as harvest index, leaf angle, and kernel size, and increased yield. The relative contribution to yield of physiological traits will be determined for each breeding programme's target environments, which may result in new selection targets or emphasis in selection indices. Sharing genetic improvements between diverse breeding programmes will provide a foundation for delivery of increased wheat yield in the form of new spring and winter wheat cultivars adapted to each of the target environment.

The results of the proposed work will positively impact national spring and winter wheat breeding programmes in Canada and the UK, and wider international efforts typified by the International Wheat Yield Partnership (IWYP), by improving access to potentially new sources of higher yielding germplasm. It will also improve the understanding of which yield traits can be introgressed into breeding programmes to deliver stable yield gains across diverse growing environments.

Furthermore, the data produced by the phenomics programme will be used to identify key physiological traits that may be used to indirectly select for yield and yield stability. This information, combined with the access to novel germplasm, will lay the foundation for future breeding work that will capture these traits in high performing, high quality wheat cultivars that will be delivered to growers throughout the world

The role of IWYP is crucial to this project as provides the platform for synergies between national programmes, in this case between AAFC partners and the UK's Designing Future Wheat programme funded by BBSRC. Such cross-national efforts will underpin future wheat breeding programme through the efficient use of knowledge, germplasm and resources. By developing wheat cultivars that have transferable traits of benefit, their impact will be felt beyond national boundaries, particularly in the developing world where facilities to breed wheat cultivars tailored to local conditions are relatively limited.

In the future, once new wheat cultivars are in the public domain, various other stakeholders will benefit, from growers who will have access to crops of predictable yield in environmentally diverse conditions to consumers, particularly in countries where wheat is a staple of national diets, who will be able to buy food at affordable and stable prices over the years. Policy makers will benefit by delivering on their vision and ambition, for example, the BBSRC's strategic framework of Agriculture and Food Security, which it has identified as an area of key economic and societal importance to the UK and globally