[Edit] An update on this post is here.
The National Institute of Agricultural Botany (NIAB) announced this week that it has ‘recreated the original rare cross between an ancient wheat and wild grass species’ that happened about 10,000 years ago.
After that cross happened, our ancestors had the plant we now call the common wheat (Triticum aestivum). It’s become one of the most important staple foods in the world, alongside rice (Oryza sativa) and maize (also known as corn, Zea mays). Here’s an article reminding us why we care about wheat.
Wheat research is being done at the International Maize and Wheat Improvement Center which is known by its Spanish acronym, CIMMYT. CIMMYT is a member of the CGIAR Consortium which was formerly known as the Consultative Group on International Agricultural Research. CIMMYT and CGIAR work together, with others, to promote food security in the developing world at WHEAT.
Thinking again of NIAB, the new wheat hasn’t yet got a catchy name. It’s called Synthetic Hexaploid Wheat (SHW). ‘Synthetic’ because making it involved biotechnology. It didn’t involve genetic engineering (GE, also known as genetic modification, GM) which would mean cutting and pasting the actual DNA strands. Instead, the parent plants were crossed with one another in a greenhouse. Then the seeds were cultured in a lab so that they’d germinate.
The new wheat is called ‘Hexaploid’ because its chromosomes come in sets of six. One of its parents was a wild plant, Tausch’s goatgrass (Aegilops taucshii). That grass is diploid. Its chromosomes, like our own chromosomes, come in pairs. The other parent plant was the hard-grained, protein-rich durum wheat (Triticum turgidum ssp. durum). That kind of wheat is tetraploid, meaning that its chromosomes come in sets of four. When diploid A. taucshii was crossed with tetraploid T. turgidum, the offspring were hexaploid.
Here’s a guide to the world of wheat naming. Gulp. A sandwich will never look simple again. It doesn’t make you feel like arguing with a name like ‘SHW’, does it? Anyway, there’s time for somebody to come up with a catchy name. NIAB tells us that farmers have to wait another few years before the new wheat, and its descendants, will become available to sow.
The next steps in developing the new wheat will involve crossing it with existing strains of T. aestivum. That crop is hexaploid because its ancestors were the same species which have now been used to make the new SHW. So it shouldn’t be too hard to cross the old hexaploid with the new hexaploid. After that, the plant breeders will select for the traits that farmers want. Higher productivity, resistance to pests and diseases, ability to withstand unpredictable weather. They might even do some more biotechnology – this time, GM to introduce desirable traits.
Whether or not GM wheat is on the horizon, this week’s announcement from NIAB opens up a new prospect for wheat. 10,000 years of selective breeding have given us many varieties. Wheat yields have risen dramatically over those years, but you can only go so far when you’re working with the descendants of one cross. Now there’s a new cross – SHW – and we can hope for a whole new set of wheat varieties.