Inferring the agrobiodiversity of Vitis vinifera L. (grapevine) in ancient Greece by comparative shape analysis of archaeological and modern seeds

Abstract

The origins and biogeographical history of Vitis vinifera L. (domesticated grapevine) remain largely unknown. Shape and size have long been used as criteria to distinguish between wild and domesticated grape pips. Here we have analyzed variations of seed morphology in order to provide accurate criteria for the discrimination of different groups of varieties. Diversity in present-day cultivars and wild grapevines of Greek and east Mediterranean origin in relation to other Asiatic and European varieties and wild grapevines provides the basis for our analysis, which aims to allow the characterization of the ancient diversity of cultivated grapes in relation to present-day cultivars. Geometric morphometric analyses (Elliptic Fourier Transform method) have been used to characterize the seed shape and size of modern and archaeological material using 40 variables per seed. 197 archaeological grape pips from the 7th century BC sanctuary of Hera in Samos, Greece were compared with an extended reference collection of 269 modern cultivars and 83 wild populations, 10,518 seeds in total. Our study confirms the relationships between seed shape and domestication. Modern diversity is partly structured by the geographical origin of cultivars, but influence of other factors may play a significant role in clustering. The wide diversity of varieties offered at the Heraion of Samos during the Archaic Period, including cultivars growing on the island, imported grapes and wild morphotypes, is related to the history and geographical location of the island as well as to the diversity in the geographical range of pilgrims making offerings to the sanctuary.

Searching for the Origins of Bere Barley: a Geometric Morphometric Approach to Cereal Landrace Recognition in Archaeology

“…Perez et al 2006;Ottoni et al 2013). In archaeobotany, GMM has proven successful in identifying fruit crop varieties from the shape of pips of grapevine (Vitis vinifera L.) (Ucchesu et al 2016;Pagnoux et al 2015;Bouby et al 2013;Terral et al 2010;Orrù et al 2013), and fruit stones of date palm (Phoenix dactylifera L.) (Terral et al 2012), cherry (Prunus avium L.) (Burger et al 2011) and olive (Olea europaea L.) (C. Newton et al 2014;C. Newton et al 2006;Terral et al 2004).…”

“…The identification of varieties for these taxa is not possible using traditional archaeobotanical techniques, and so variety recognition using GMM permits a re-evaluation of the economic and social role of these past crops (e.g. Pagnoux et al 2015).…”

Long and attenuated: comparative trends in the domestication of tree fruits

“…All specimens in the UCL archaeobotanical reference collection; scale bars 1 cm that wild and domesticated populations fall towards different ends of a morphological spectrum seems clear. Indeed, studies employing geometric morphometrics (GMM) on grapes (Vitis vinifera) (Pagnoux et al 2015;Bacilieri et al 2017), as well as on other taxa such as olives (Olea europaea) (Terral et al 2004;Newton et al 2014), plums (Prunus domestica) (Ucchesu et al 2017) and dates (Phoenix dactylifera) (Rivera et al 2014;Gros-Balthazard et al 2016), which factor out size and focus instead on shape, demonstrate statistically shape differences between wild and cultivated forms of these fruits, as well as among different cultivar groups. Domesticated forms have higher L:W ratios and tend to have more pointed (acute to acuminate) ends.…”

Identification of inter- and intra-species variation in cereal grains through geometric morphometric analysis, and its resilience under experimental charring

“…The manner in which this is achieved depends on whether there are many features present that can be landmarked, or 100 whether curves, outlines and surfaces are the shapes' main homologous features. Recently, application of geometric morphometrics to archaeobotanical material has proven helpful to aid species identification (García-Granero et al, 2016) and, beyond this, to examine variation within species (Burger et al, 2011;Newton et al, 2006;Orrù et al, 2013;Pagnoux et al, 2014;Ros et al, 2014;Terral et al, 2012Terral et al, , 2010Terral et al, , 2004Ucchesu et al, 2016). Studies 105 to date have, however, focused on fruit stones such as grape and olive, while the application of geometric morphometrics to cereal grains has been treated with caution due to the known shape distortion caused by charring of starch-rich grain compared with the relative shape stability of woody fruit stones.…”