Mariano Ucchesu

Archaeobotanical analysis of a Bronze Age well from Sardinia: A wealth of knowledge

In 2008, during a rescue excavation in the Sa Osa area, near the town of Cabras (Sardinia, Italy), a Nuragic settlement was discovered. The excavation revealed numerous pits, wells and structures dug by the local communities between the Early Copper Age and the Iron Age. These structures were interpreted as elements of a settlement mainly involved in primary production. The most remarkable structure is Well-N, radiocarbon and archaeologically dated to the Late Bronze Age, which has yielded large amounts of waterlogged plant remains, animal and fish bones and pottery. Despite the limited set of samples, the combination of macro-remain and pollen analyses in this unique context provides important information useful for exploring not only local subsistence systems but also human impact on the surrounding environment. Grapes and figs are the most abundant remains together with other fruits and edible vascular plants. Remains of melon and mulberry were identified being the earliest remains of these two species for Western Europe. Their presence may confirm early trade between Nuragic people and the eastern Mediterranean and/or African coasts. Intentional selection of wood suggests practices associated to the collection of raw material for specific technological demands. The presence of intestinal parasites in the pollen record points to the possible use of the well as a cesspit, at least in its later use, and this is one of the earliest evidence of this type of structures in prehistoric contexts.

Predictive method for correct identification of archaeological charred grape seeds: Support for advances in knowledge of grape domestication process

The identification of archaeological charred grape seeds is a difficult task due to the alteration of the morphological seeds shape. In archaeobotanical studies, for the correct discrimination between Vitis vinifera subsp. sylvestris and Vitis vinifera subsp. vinifera grape seeds it is very important to understand the history and origin of the domesticated grapevine. In this work, different carbonisation experiments were carried out using a hearth to reproduce the same burning conditions that occurred in archaeological contexts. In addition, several carbonisation trials on modern wild and cultivated grape seeds were performed using a muffle furnace. For comparison with archaeological materials, modern grape seed samples were obtained using seven different temperatures of carbonisation ranging between 180 and 340ºC for 120 min. Analysing the grape seed size and shape by computer vision techniques, and applying the stepwise linear discriminant analysis (LDA) method, discrimination of the wild from the cultivated charred grape seeds was possible. An overall correct classification of 93.3% was achieved. Applying the same statistical procedure to compare modern charred with archaeological grape seeds, found in Sardinia and dating back to the Early Bronze Age (2017–1751 2σ cal. BC), allowed 75.0% of the cases to be identified as wild grape. The proposed method proved to be a useful and effective procedure in identifying, with high accuracy, the charred grape seeds found in archaeological sites. Moreover, it may be considered valid support for advances in the knowledge and comprehension of viticulture adoption and the grape domestication process. The same methodology may also be successful when applied to other plant remains, and provide important information about the history of domesticated plants.

First finds of Prunus domestica L. in Italy from the Phoenician and Punic periods (6th-2nd centuries BC)

During the archaeological excavations in the Phoenician and Punic settlement of Santa Giusta (Oristano, Sardinia, Italy), dating back to the 6th–2nd centuries bc, several Prunus fruitstones (endocarps) inside amphorae were recovered. The exceptional state of preservation of the waterlogged remains allowed morphometric measurements to be done by image analysis and statistical comparisons made with modern cultivated and wild Prunus samples collected in Sardinia. Digital images of modern and archaeological Prunus fruitstones were acquired with a flatbed scanner and analysed by applying image analysis techniques to measure 26 morphometric features. By applying stepwise linear discriminant analysis, a morphometric comparison was made between the archaeological fruitstones of Prunus and the modern ones collected in Sardinia. These analyses allowed identification of 53 archaeological fruitstones as P. spinosa and 11 as P. domestica. Moreover, the archaeological samples of P. spinosa showed morphometric similarities in 92.5% of the cases with the modern P. spinosa samples currently growing near the Phoenician and Punic site. Likewise, the archaeological fruitstones identified as P. domestica showed similarities with the modern variety of P. domestica called Sanguigna di Bosa which is currently cultivated near the village of Bosa. Currently, these findings represent the first evidence of P. domestica in Italy during the Phoenician and Punic periods.

Phenotypic identification of plum varieties (Prunus domestica L.) by endocarps morpho-colorimetric and textural descriptors

P. domestica endocarps biometric features were measured by image analysis techniques.A total of 134 size, shape, color and texture descriptors were measured on each endocarp.The data were statistically processed applying the stepwise Linear Discriminant Analysis.Hypothetical synonymy groups were identified.This is the first computer vision application on plum biodiversity study. The identification of plum varieties is generally done on the base of distinctive plant traits such as shape, size, and fruit drupe color identified during the variety registration, following official descriptors. In this paper, image analysis techniques were applied to study endocarps variability of 23 Prunus domestica cultivars from Sardinia. Digital images were acquired and analysed using a macro specifically developed to measure morpho-colorimetric endocarps features. The data were later statistically processed applying the stepwise Linear Discriminant Analysis (LDA) to implement a statistical classifier able to classify each variety and identify plausible synonymy groups.The present study represent the first attempt to investigate the morphology and morphometry of plum endocarps in order to characterize the whole Sardinian plum agrobiodiversity. It is also the evidence of the usefulness of image analysis techniques in taxonomic investigations too, as well as for the conservation and enhancement of traditional plums for consumer satisfaction.

New insights about economic plants during the 6th–2nd centuries bc in Sardinia, Italy

A research project carried out in Santa Giusta lagoon, Sardinia, since 2005 has revealed the presence of Phoenician and Punic waterlogged archaeological contexts of exceptional importance. Several transport amphorae, together with Punic coarse pottery and materials typical of funerary and votive contexts have been recovered. Two principal deposition phases have been distinguished, the first one dated to the 6th–5th century bc and the second dated to the 3rd−2nd century bc. The waterlogged conditions favoured the preservation of plant remains such as Citrullus lanatus, Corylus avellana, Juglans regia, Juniperus oxycedrus, Lagenaria siceraria, Olea europaea, Pinus pinea, P. halepensis, Prunus dulcis, P. domestica, P. spinosa and Vitis vinifera. Many amphorae contained ovine/caprine bones with slaughter or butchering marks, associated with grapes and other juicy fruits that have been interpreted as possible ingredients used as meat preservatives. This study provides information on the management of plants of economic importance for the Phoenician and Punic communities in Sardinia.

Seed morphometry is suitable for apple-germplasm diversity-analyses

Abstract The main objective of this study was to evaluate the trustworthiness of seed image analysis as an approach to discriminate apple germplasm accessions. Digital images of seeds from 42 apple cultivars, acquired by a flatbed scanner, provided a phenotypic dataset with 106 morphometric variables. Stepwise Linear Discriminant Analysis (LDA) was used to examine this dataset, and the results were compared with available genetic data. The first comparison among cultivars provided a 38.8% cross-validation of correct identifications with a discriminant percentage ranging between 11.7 and 70%. In agreement with the genetic diversity analysis, the LDA could discriminate between the apples cultivars, identifying two main groups that could be further divided into additional subgroups. Based on our findings, we propose that seed image analysis is a valuable and affordable tool to investigate phenotypic diversity among a large number of apple cultivars.

Molecular and morphological characterisation of the oldest Cucumis melo L. seeds found in the Western Mediterranean Basin

In 2008–2009, a rescue excavation uncovered an intact Late Bronze Age well in Sa Osa, Sardinia (Italy). The structure yielded a large number of waterlogged plant remains, of which a group of melon seeds (Cucumis melo L.) were some of the most remarkable. These seeds represent the earliest recorded remains of this taxon in the Western Mediterranean and are some of the oldest ever recorded. The plant remains were preserved in anoxic conditions and were found in a perfect state of conservation, making them ideal candidates for morphometric and molecular characterisation. A total of 96 parameters, measured using an automatic image analysis system, were specifically designed to evaluate the morphological features of 15 preserved whole seeds. DNA extraction from archaeological samples followed a procedure specifically set up to avoid any kind of contamination. A 123-SNP genotyping platform that had been validated previously was used. The morphological and molecular data of the archaeological seeds were successfully compared with those of a set of 179 accessions, including landraces, of feral and wild melons from Europe, Africa, and Asia. Both analyses confirmed that these ancient seeds did not belong to a wild melon, but instead to a cultivated one. This primitive melon could have belonged to a group of ancestral non-sweet or semi-sweet forms of chate, flexuosus, or ameri varieties, showing similarities to North African and Central Asian accessions. This finding is coherent with the reportedly important role of cucumber-like melons in the species’ diversification process and with the accepted role of the ameri group as the ancestors of the modern sweet varieties.