Wiebke Kirleis retrieving a 18th century AD Wellerholz from the Knochenhauer Straße 2 in Einbeck (Photo by: S. Filatova).

The traditional notion of the process of plant domestication, known as the core area hypothesis, is that it occurred intentionally, as a rapid event in a specific location. During the past two decades, however, archaeobotanical and molecular studies have suggested a more diffuse and extended set of processes, which included both intentional and unintentional acts. Instead of plant domestication being a rare, linear event that occurred only on a limited chronological and temporal scale, it is currently understood as a complex set of processes that are related to, amongst others, human tendency to manage their surroundings for subsistence, local ecological conditions, and plant population genetics.
In the project “Genetic variation in ancestral crops”, we focus on various aspects of plant-based and animal-based diets and thereby aim to understand the relationship between (co-)evolutionary processes of plants/animals, environmental factors, agricultural practice and food culture. From this perspective, rye (Secale cereal L.) forms an excellent case-study of the complex set of processes that encompass plant domestication. The first indications for rye cultivation originate from the Late Epipaleolithic and Neolithic in Syria and Anatolia, respectively. These early cultivation practices were, however, abandoned, suggesting several local and brief domestication events of rye in the Fertile Crescent. During the Neolithic, rye was introduced into Europe not as a crop, but as a weed in wheat and barley fields. It already possessed several domestication traits (e.g. grain size and tough rachis), which it had acquired by adapting the size and weight of its grains to that of wheat rather than through intentional human selection.
It was not until the pre-Roman Iron Age that rye cultivation started to blossom in Northern and Central Europe, reaching its height in the high Middle Ages and early Modern Times. The adoption of rye as a crop is believed to have been stimulated by the introduction of the practice of harvesting close to the ground and by climatic deterioration. During most of prehistory, harvesting took place by cutting the crops near the ears. Rye is a tall-growing cereal, reaching beyond wheat and barley in height, and is therefore easily separated from wheat and barley during ear harvest. When harvested close to the ground, however, separating the weedy rye from wheat and barley is more challenging, increasing the presence of rye in the yield. Furthermore, rye has a competitive advantage to wheat especially, being able to tolerate unfavourable environmental conditions, such as poor soils and harsh winters. It is therefore likely that climatic deterioration combined with the development of harvesting near the ground, contributed to the introduction of rye cultivation in Northern and Central Europe.
Besides being one of the most significant cereals for bread baking in Northern and Central Europe from the high Middle Ages onwards, the tough straws of rye have provided important sources for insulating materials and roof covers. The material starting point of our project is therefore the “Wellerholz” from Medieval and early Modern half-timbered houses from various regions in Germany. Our goal is to use archaeobotanical analysis in order to gain insight into agricultural practice, as well as to apply ancient DNA analysis in order to reveal how and when specific traits developed that today are considered to be characteristic of domesticated rye. We are hereby hoping to compare data from cultivars that originate from different parts of Germany and thus potentially look into the development of landraces.

Ben Krause-Kyora and Eva Stukenbrock selecting remains of rye for aDNA analysis (Photo by: UFG Kiel).

Sofia Filatova processing a Wellerholz from the old Rathaus in Göttingen (14th century AD) for archaeobotanical analysis (Photo by: Y. Dannath).

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Project by Benjamin Claaßen Claaßen, Benjamin, Sonja Filatova s.filatova@ufg.uni-kiel.de , Wiebke Kirleis wiebke.kirleis@ufg.uni-kiel.de, Ben Krause-Kyora b.krause-kyora@ikmb.uni-kiel.de, Almut Nebel a.nebel@mucosa.de, Eva Holtgrewe Stukenbrock estukenbrock@bot.uni-kiel.de