Programme Leader: Graham Moore
National wheat pre-breeding research
Programme Leader: Graham Moore
A research project funded by BBSRC and coordinated by the John Innes Centre aims to bridge the gap between publicly-funded plant science and private breeding companies. The research is in its second year, and from 2014 will become an Institute Strategic Programme.
The world is facing a potential crisis in terms of food security due to population expansion, dietary changes, declining stocks of fossil fuels, and a failure of conventional wheat breeding methods to sustain yield gains.
Over the next 50 years, more wheat needs to grown than has been produced in the 10,000 years since agriculture began.
In the UK 18 million hectares, or around three-quarters of UK land, is used for agriculture. But up to six times that is actually needed to supply all the resources we require and to absorb all the waste we generate. We make up the shortfall by paying for it using wealth created from our service sector. This is not sustainable.
In the US, advances in biotechnology will help double maize yields by 2030. The aim is to achieve this on 30 per cent less land, using less water and less energy.
The UK needs a similar vision to improve major crops such as wheat, ensuring the UK makes a major contribution to global food security. We aim to address that need by collaborating with wheat researchers at other institutes and universities on a collaborative pre-breeding programme.
The wheat story so far
A chance hybridization 10,000 years ago enabled humans to start harvesting and domesticating wheat, eventually leading to the elite lines of modern bread wheat currently in use.
Today it is the UK’s largest crop. Worldwide, more land is used to grow wheat than any other crop. It has overtaken rice to become the second most produced cereal after maize.
Domestication increased yields, but recently those increases have slowed. This is partly because domestication has eroded wheat diversity. The possibilities for improvement are reaching their limit. Experimental crosses will allow new and useful genetic variation to be identified from wheat parents. Some varieties may show poor agronomic performance but contain lost genes and traits valued for improving performance and for adapting crops to UK and global agriculture.
We aim to rejuvenate wheat diversity, prioritising valuable traits from wild wheat, a worldwide collection of locally-adapted primitive varieties (or ‘landraces’), ‘synthetic’ bread wheat, and other grasses. We will incorporate this diversity into elite UK varieties; ensuring breeders can quickly apply it to make improvements in the field.
Sources of diversity
Three sources of diversity will be used. Untapped genetic variation in existing UK and worldwide land races will be identified, most importantly from the AE Watkins landrace collection in the BBSRC small grain cereals collection held at JIC. Scientists will also recreate the original cross that produced the first bread wheat to capture diversity from modern wheat’s ancestors. The resulting varieties are known as synthetic wheat. Wild and cultivated relatives will provide further diversity.
Tomorrow’s wheat - widening the gene pool
In this multi-site research programme, publicly-funded scientists will collaborate on producing new lines of bread wheat with improved resistance to diseases and insects, greater tolerance to drought, salt and heat, and enhanced yield. Breeders will be able to take them on for further selection to produce elite varieties for release.
Breeders have already identified key agronomic traits of most interest to them, and academics will also pursue target traits, for example linked to environmental benefits.
The research will broaden the gene pool, or ‘germplasm’, for wheat. All the information, such as the genetic markers required for precision breeding, will be stored in a central database. The seed will be stored at JIC’s Germplasm Resource Unit. All the information and seed will be free of patents and made freely available to breeders and researchers worldwide.
The genes that control important traits will be identified and then mapped on the wheat genome, making it easier for breeders to select them in marker assisted breeding. The research will ensure that the greatest possible diversity is used.
Some of the first traits explored will be resistance to aphids, bulb fly and Take-All.
To improve yield, traits that improve biomass will be identified. These traits include the efficiency with which a plant photosynthesises, the way a leaf ages, and how that effects the growth of the stem and the grain, and leaf architecture.
Varieties with enhanced nitrogen and phosphate use will be developed to reduce the amount of fertiliser needed on crops.
Capturing and exploiting diversity
The parental material used in the initial pre-breeding crosses will be genotyped, revealing the genetic differences between varieties. This will help ensure that maximum diversity is exploited.
Using the most advanced sequencing techniques we will generate very high density maps of markers linked to target genes. So-called second and third generation sequencing will enable us to provide breeding companies with markers for “precision” breeding, and academia with markers for fine dissection of key traits.
Throughout the three years of the current project, and looking ahead to the formal research programme, all partners will work together to collect genotyping and phenotypic data in a database. This database will show the links between genes and traits.
Training the next generation
Wheat is a particularly complex cereal to study. Some varieties have two sets of chromosomes (diploid), some have four (tetraploid) and others six (hexaploid). The wheat genome is 30 times larger than that of rice and five times larger than the human genome.
The UK currently has the skill base to deliver the challenging research needed, but many wheat researchers are due to retire in the next five to ten years. The resources created by the pre-breeding programme will help young researchers initiate their own wheat research projects. The pooling of expertise will make it easier to train the next generation of scientists in skills needed for population development, phenotyping and genotyping.