The evolutionary relationship between bere barley and other types of cultivated barley

Abstract

We used genotyping-by-sequencing to investigate the evolutionary history of bere, the oldest barley variety still cultivated in Britain and possibly in all of Europe. With a panel of 203 wild and 401 cultivated barley accessions, including 35 samples identified as bere, we obtained filtered datasets comprising up to 1,946,469 single nucleotide polymorphisms (SNPs). The beres formed two genetically-distinct groups, the larger of which included beres from Orkney and the Scottish Western Isles, as well as varieties not identified as bere from the Faroe Islands. This group of beres was distinct from other British barleys, but had a close genetic affiliation with Scandinavian accessions. Although the data were partly compatible with the traditional view that bere was introduced to Scotland by the Vikings during the eighth century AD, the evidence as whole suggested that the bere and Scandinavian barleys are sister groups descended from a more distant common progenitor, possibly dating to the Bronze Age when hulled barleys first become common in northern Europe. More recently, there has been gene flow from these beres into Polish barleys, possibly following export of grain to the Baltic region during periods when Orkney was under Norwegian or Danish rule. A second, smaller group of beres, which included a traditional Welsh variety, was genetically distinct from the main group and probably represents a more recent introduction of barley from central Europe. Our results emphasize the uniqueness of bere barley and its importance as a heritage crop and a potential source of germplasm for breeding programmes.

Climatic controls on the survival and loss of ancient types of barley on North Atlantic Islands

“…Reinavelta was already well established by the seventeenth century (Christiansen 1989) and amongst its adaptations to Faroese conditions (Supplementary Note 4) were sloping beds with drainage channels to cope with high rainfall, and heavy applications of seaweed and manure to maintain soil fertility. The surviving lines of Faroese barley are closely related to bere and, although one suggestion is that they were eighteenth or nineteenth century introductions (Wallace et al 2019), they might also be descended from barley introduced by Norse settlers from Scotland as discussed in Drosou et al (2022). However, our reconstruction of CSDD identified 15 periods from 1200 to 1900 with four or more consecutive years below the LYI (Table S5) and with three in the thirteenth century being especially protracted.…”

“…With a significant proportion of Norse settlers in both the Faroes and Iceland originating from Scandinavian colonies in the British Isles (Zori 2016;Als et al 2006), it is possible that bere was taken to these other islands. A close relationship between traditional Faroese barley and bere is suggested by grain morphometrics and genotyping (Wallace et al 2019;Drosou et al 2022), similarities in agrophenology (Agronomy Institute unpublished results) and historic references (Trevelyan 1835;Williamson 1970).…”

“…Although there is little information about the varieties of barley grown on North Atlantic islands in Norse times, they were mainly 6-row, hulled types (Church et al 2005). In Scotland, they included ancestral types of today's bere, an ancient barley which probably existed in the region before the Norse occupation (Drosou et al 2022). Bere exhibits several adaptations which make it well suited to the Scottish Isles.…”

Trends, challenges and opportunities in the in situ conservation of cereal landraces in Scottish islands

“…Bere was probably the earliest of the three cereal landraces to be introduced to Scotland, most likely during the Bronze Age or possibly in the Neolithic (Drosou et al, 2022). Small oat and Hebridean rye were probably more recent introductions, with oats first appearing at archaeological sites during the Iron Age (Bond, 1998) and rye during Viking times when there was an intensification of cereal production in the Scottish Isles (Smith, 2005).…”

“…Within the United Kingdom (UK), the agricultural regions where landrace cultivation and resulting diversity are greatest, are the Scottish archipelagos of Orkney and Shetland (the Northern Isles) and the Outer Hebrides (Kell et al, 2009) (Figure 1). The main landraces grown are three cereals: bere, 1 an ancient type 1 Under current terminology the name 'bere' is used to describe a distinct landrace population of lax-eared, 6-row, hulled spring barley that has been grown in Scotland and the north of Britain for over 1,000 years (Drosou et al, 2022). In the past, several synonyms appear to have been applied to bere including 'beare', 'bygg' or 'bigg' (Jarman, 1996;Wallace et al, 2019).…”