Approaches and constraints of using existing landrace and extant plant material to understand agricultural spread in prehistory

Abstract

The potential for the phylogeographical analysis of cereal landraces to determine the initial patterns of agricultural spread through Europe is discussed in relation to two of the first cereals to be domesticated, emmer wheat (Triticum turgidumsubsp.dicoccum) and barley (Hordeum vulgare). Extant landraces available from germplasm collections have a patchy distribution, largely being confined to regions of rugged upland topography, and the phylogeographical patterns observed may be due to ‘overstamping’ by more recent crop movements. Phylogeographical studies of non-viable historical landrace material held in herbarium and old seed collections and found in historical buildings have the potential to fill in the gaps in time and space. We explore the importance of precise geographical provenance and the limitations of this in extant and historical material. Additionally, we consider the effect of various chemicals and the preservation of DNA in the historical material.