Ancient Barley Could Help Farmers Adapt to Changing Climate

By John Roach

DNA has been recovered from an ancient form of barley that persisted for more than 3,000 years and the tastes of five civilizations in Egypt’s upper Nile, according to a new study.

The barely was particularly well-adapted to the region’s parched climate, allowing it to trump more bountiful but less hardy varieties, according to genetic analyses of the preserved grains.

The finding could assist efforts to breed modern crops that are able to survive a drying climate, noted plant researcher Robin Allaby, an associate professor at the University of Warwick in the UK.

“If we find genes that have evolved to cope with arid conditions, we can then look to transferring those genes, or replicating those genes in modern varieties,” he explained to me in an email exchange.

Domesticated Grain

Barley was the first cereal grain to be domesticated, about 9,500 years ago, Allaby and his colleagues note in a paper published last week in the journal PLoS One.

The grain is widely used today for animal feed and brewing beer.

Natural, wild forms of barely tend to be two row varieties. Most farmers prefer six row varieties which can yield up to three times as many grains, according to the researchers.

Although the six row version has been grown for more than 8,000 years, the ancient variety at Qasr Ibrim was a two row version.

The researchers considered this curious because the six row version was grown in the lower Nile, suggesting that the nearby occupants of Qasr Ibrim deliberately selected the two row version.

“It certainly seems to be the case that the two row triumphed over others at Qasr Ibrim,” Allaby said.

But why?

The DNA analyses revealed that the site’s two row variety wasn’t typical of wild two eared barley, but was rather a mutated form of six row barley.

According to the paper, natural selective pressures must be responsible for the persistence of the two row mutation though five civilizations.

The upper Nile is arid relative to the lower Nile. Studies have shown that two row varieties can survive water stress better than six row, suggesting a possible selective pressure, the researchers note.

Feed – and Beer?

Allaby said the barley at Qasr Ibrim was primarily used as animal fodder – evidence for grains and chaff are present in preserved animal dung, for example.

Brewing beer also has a long tradition in the region and “there is a possibility they were using the barley for beer,” he said.

However, direct evidence for brewing is sparse. There are no traditional Egyptian beer jars, for example, and some of the beer brewed in the region was made with sorghum, not barley.

“There are a few large pots with a coarse residue present in them which contain hulled barley and wheat remains, which may suggest beer brewing,” Allaby said.

“But until there is better evidence, it is difficult to prove.”

Top image: Barley (Hordeum vulgare). Barley was domesticated by 8000 B.C., probably in the Middle East. Hull-less barley can be grown in winter on the same land used for summertime corn and soybean production—thus preventing winter soil erosion—and requires fewer soil amendments for cultivation. Photo by Doug Wilson.