by Joanna Wolstenholme
Looking at today’s Western world, with fast food readily available, huge problems with obesity, and a ridiculous amount of food wastage, you would never know that there is a need for more wheat. Yet with the world population rapidly expanding, and workable agricultural land area set to decrease due to rising sea levels, ever increasing cities and rising salinity, yields have got to rise dramatically.
Prof. Beddington stated at the 2009 BBRSC Food Security Summit that “we need 50% more production by 2020, on less land, less water, using less energy, less pesticides and less fertiliser.” That is quite a challenge, not helped by the fact that wheat yields in the UK (one of our most important cereal crops) have plateaued since 1999, and this is a trend that is starting to be repeated across the world. If wheat yield remains static we will need 360 million more hectares of agricultural land in order to meet the 2030 target. That is equivalent to 24 UKs.
It is at times like these that the plant science sector comes into its own. Rather than increasing agricultural area, scientists are working to increase the yield of wheat, to get more food out of the land we already have. In the UK, the Wheat Improvement Strategic Program (or more snappily WISP), coordinated by the BBSRC, has been set up to help meet Prof. Beddington’s target. This collaboration encompasses a variety of projects, based at the John Innes Centre, NIAB and Nottingham University. They are using mostly traditional breeding techniques (allowing them to bypass the time consuming ethical maze that surrounds GM) to introduce new genetic material, and quantify the variety that is already there. Backcrossing current commercial varieties with older wheat strains allows new diversity to be created, widening the frighteningly small genetic diversity of the current commercial wheat strains.
Andy Greenland’s group at NIAB, however, has taken it one step further, and is ‘resynthesizing’ wheat – by crossing a diploid (having 2 chromosomes) goat grass (Aegilops tauschii) with tetraploid (4 chromosomes) wheats such as wild and cultivated emmer wheat (Triticum dicoccoides and T. dicoccum) and durum or pasta wheat (T. turgidum). This allows him to recapture the moment that occurred some 10,000 years ago in the fertile crescent, when the first hexaploid (6 chromosome-d) wheat was created. These new ‘synthetic wheats’ will be crossed with bread wheat to create ‘pre-breeding’ material suited to the UK climate. Already this project is showing promise – this new ‘superwheat’ (as it has been coined by the press) has shown yields of up to 30% more than normal varieties, and is able to cope with low nitrogen soils, meaning that it will require less fertilisers.
Whilst the work being carried out by the WISP collaborators is incredible in itself, there is one factor that makes it very special in my eyes. All the results of crosses and genetic analyses, along with the germplasm (small pieces of living tissue from which new plants can be grown) will be freely available. This means that plant breeders can use the germplasm to cross with their existing lines, which will speed up the vital process of getting this new research into commercial varieties. Additionally, academics will be able to use this information to further their own research in the area. Without such open collaboration, it would be much harder to make use of any important discoveries, and use them for what they were intended for: to increase wheat yield and help feed the world.
Finally, to underline the importance of such work: in the next 50 years, we will need to harvest as much wheat as has been produced since the beginning of agriculture, which was some 10,000 years ago.