Was barley locally adapted to drought conditions in ancient Nubia?

Nubian barley - Summary One of the most serious challenges in the future of agriculture in the face of an increasing global population and climate change is water availability. However, we are not the first to face this problem. Lessons may be learned from past civilizations that grew crops in extreme environments for thousands of years. Evidence suggests that landraces of crops may have been in place for several millennia and likely to be specifically well adapted to their local environment. In effect, such landraces represent the efforts of thousands of years of selective breeding that should be regarded as an irreplaceable genetic resource. Unfortunately, many such landraces have now been lost by replacement with modern varieties. In some instances, we have access to those landraces through archaeobotanical remains. This study focuses on an area of the world associated with ancient Egypt - Nubia. The populations of southern ancient Nubia faced an environment in which water stress was a way of life. Interestingly, archaeobotanical samples of the 'smaller' barley that they grew shows some evidence of being adapted to drought conditions in a way that is not seen in the modern world. Furthermore, it seems that successive cultures from outside the region adopted this barley type, rather than introduce their own superficially higher yielding 'larger' varieties such as was grown in the Western Oases, and further north up the Nile Valley where water was not so scarce. We think this is because the Nubian barley was better suited to the harsh environment of the southern Nile Valley than outside varieties. In this case perhaps small was more beautiful. In this project we intend to examine a large portion of the barley genome (0.5%) most likely to be affected by drought stress in archaeobotanical samples from Nubian sites spanning 3000 years to find out if and how these ancient landraces became better suited to their environment. We will determine whether 'adapted' alleles could be utilized as a genetic resource for future breeding programs. We will also find out whether the landrace was kept 'pure', or whether a type was maintained with an influx of genetic material with new cultures. This study will provide us with important insight into the extent to which crops spread with culture or became locally adapted to the benefit of many cultures, and whether the ancient populations of Nubia solved problems of water shortage genetically in ways that will help us face the future.