Studying the current diversity of barley using geometric morphometrics on modern seeds: protocol and first results

Abstract

International audienceGeometric morphometrics is a powerful method to explore intraspecies variation in cultivated plants (Terral et al., 2012 ; Bonhomme et al., 2017). Barley (Hordeum vulgare L.) is one of the staple crop of the Mediterranean since the Neolithic (Zohary et al., 2012). While morphological discrete characters are available to distinguish two-rowed from six-rowed barley, and naked from hulled barley (Jacomet et al. 2006), quantitative approaches still need to be developed at a large scale. The aim of this study is to explore the morphometric grain variation between barley varieties, six- and two-rowed types, naked and hulled types and spring and winter varieties. Size and shape of 2950 modern barley seeds from 84 current varieties provided by the Small grain cereals Biological Resources Centre (INRAE, Clermont Ferrand, France) were quantified using Elliptic Fourier Transforms (EFT) applied to gain outlines 2D coordinates. Results open interesting perspectives for investigating archaeological barley seeds and trace barley evolution in the western occidental Mediterranean basin since the Neolithic. This perspective will be realized in the framework of the ERC project DEMETER (grant agreement No. 852573)