New insights into the origins of agriculture in the Fertile Crescent

Dr Catherine Preece and colleagues from the University of Sheffield studied cereal crops that originated in the Fertile Crescent, an arc of land in western Asia from the Mediterranean Sea to the Persian Gulf, encompassing the Tigris and the Euphrates.

They grew wild versions of wheat and barley along with other grasses from the region to identify the traits that make some plants suitable for agriculture, including how much edible seed the grasses produced and their architecture.

"Our results surprised us because numerous other grasses that our ancestors ate, but we do not, can produce just as much seed as wild wheat and barley. It is only when these plants are grown at high densities, similar to what we would find in fields, that the advantage of wild wheat and barley is revealed," says Dr Preece.

The study identified two key characteristics shared by the wild relatives of current crop plants. "Firstly they have bigger seeds, which means they grow into bigger seedlings and are able to get more than their fair share of light and nutrients, and secondly, as adult plants they are less bushy than other grasses and package their big seeds onto fewer stems. This means crop wild relatives perform better than the other wild grasses that they are competing with and are better at growing close together in fields, making them ideal for using in agriculture," she explains.

The results are important because our expanding human population is putting increasing demands on food production. Before humans learned how to farm, our ancestors ate a much wider variety of grasses. If we can understand what traits have made some grasses into good crops then we can look for those characteristics in other plants and perhaps identify good candidates for future domestication.

According to Dr Preece: "To shape the future we must understand the past, so the more we can discover about the origins of agriculture, the more information we will have to help us tackle the challenges that face modern day food production."

So far the researchers have been conducting their experiments in greenhouses and their results indicate that the traits affecting how plants compete with each other are crucial factors to determining the success of a crop.

The team now plan to observe how the plants interact in their natural environment by growing them in experimental fields in Turkey, the heart of the Fertile Crescent. They hope that their experiments will yield another crop of important results. "Cereal breeders are taking an increasing interest in modern crops' wild relatives as a source of useful traits that may help to increase yields or increase resilience to climate change, and our work should help in this process."

Dr Catherine Preece will present the results of this study to the joint BES/SFE meeting on Thursday 11 December 2014 in the Grand Palais, Lille.