Breeders toolkit will help to future-proof wheat

Improved collaboration and resource sharing will be essential if yields are to be sustained, says Dr Kim Hammond-Kosack of Rothamsted Research  

The transformation of wheat from the sparse grasses first cultivated in the Fertile Crescent, to the world conquering super-grain of today has been one of humanity’s most startling achievements.

For centuries improvements were gradual, but as a more scientific approach to breeding and cultivation emerged, the pace of change accelerated. Over the second half of the 20^th century yields skyrocketed as new varieties and increased use of fertilizer and pesticides became widespread.

By the 1990s, however, UK national wheat yields seemed to stagnate with the average hovering persistently just around or below 8 tonnes per hectare.

Clearly a fresh approach was needed – not least because new threats like climate change and pesticide resistance were gathering momentum.

This new “perfect storm” of challenges coincided with the rise of gene technologies. New genetic information on wheat (and almost every other major crop) began pouring out of research labs. By one estimate, the amount of genomic data generated by researchers now doubles every seven months. These new insights can potentially provide new opportunities for crop solutions. However, the sheer volume of information generated is creating its own challenges

Alert to this impending overload, in 2003 plant scientists and commercial breeders got together to share information as part of the DEFRA funded Wheat Genetic Improvement Network (WGIN). Now entering its next stage, the project has turbocharged UK wheat breeding and is now delivering promising results.

Long-term research is teasing out which genes are responsible for traits such as yield consistency, crop resilience to pests and diseases and enhanced resource efficiency. This will offer growers of the future access to elite varieties. A cohort of UK wheat researchers have developed new genetic resources and a wide range of new techniques to identify diverse desirable traits.

The aim of WGIN is to pull all of this research together and provide wheat breeders with free access to databases, germplasm and new knowledge. This will enable them to look up genes governing a trait and, using the ‘Breeders Toolkit’, to transfer the genes of interest to new UK varieties.

However, this is a long-term investment. Breeders will need to take time in their own pre-breeding programmes to assess the value of new genetic forms. The first of these varieties may take around 10 to 15 years before they are available.

Initial studies shared by WGIN covered variety-nitrogen interaction and looked at yield, quality and nitrogen use efficiency together with year-to-year stability.

Newer research is tackling traits breeders have really struggled to make progress with such as lodging, slug resistance, resistance to Septoria leaf blotch, take-all root disease, aphids, BYDV and yield stability.

The decision to look at BYDV was prompted by new pesticide regulations and the emergence of pyrethroid resistance in the two main cereal aphid species in the UK.

Yellow rust, Septoria leaf blotch and powdery mildew will also be evaluated for yield, grain quality and resource use efficiency effects.

Seeds arising from new crosses will be available on request from the Germplasm Resources Unit (GRU), at the John Innes Centre (JIC), which is part of the WGIN collaboration.

No wheat variety is perfect, but work pulling together different traits is helping to move towards better and better varieties. That means growers will be able to obtain good yields in difficult seasons as well as when conditions are favourable.

Dr Kim Hammond-Kosack will be speaking in the Crop Breeding Seminar at Croptec 2019