Glume Wheat Research Articles

The role of Chenopodium in the subsistence economy of pioneer agriculturalists on the northern frontier of the Linear Pottery culture in Kuyavia, central Poland

When found on settlements of early European farmers, the dietary role of seeds of Chenopodium album (commonly called goosefoot or fat-hen) is difficult to assess. It is often hard to determine whether the small black seeds are modern or ancient. Rarely are they found in sufficient concentrations to warrant radiocarbon dating. Palaeobotanical sampling at the Neolithic site of Ludwinowo 7 in north-central Poland yielded abundant carbonized C. album seeds but only a modest quantity of domesticated cereals (einkorn wheat, Triticum monococcum, and the new type of glume wheat, NGW) and other cultivated plants (flax, Linum usitatissimum, and peas, cf. Pisum sativum). Samples of C. album seeds and carbonized wheat chaff from the same context produced consistent dates in the late 6th millennium B.C. The frequency of C. album type seeds at Ludwinowo suggests their presence was not incidental but intentional, contributing significantly to the diet of the inhabitants in multiple ways. We propose that wheat cultivation, although practiced, was not central to the subsistence economy of the inhabitants of Ludwinowo.

Grains from ear to ear: the morphology of spelt and free-threshing wheat from Roman Mursa (Osijek), Croatia

Cereals were a significant part of the Roman diet, yet knowledge about their cultivation, distribution and consumption in certain regions is particularly lacking. In Europe, studies generally suggest that from the Iron Age to the Roman period there was a reduction in barley cultivation, an increase in spelt over emmer, a preference for free-threshing wheat over glume wheats, as well as the increased cultivation of rye and oats. Up till now, there was little evidence on crop cultivation in Croatia, but the discovery of around 24,000 cereal grains from the oven of a 2nd-4th c. ad Roman villa in the modern town of Osijek provides important insights into diet and subsistence in the Roman province of Pannonia. Here, the dominance of free-threshing wheat, spelt and rye with only a relatively small amount of other cereals, chaff and weeds corresponds well with this pattern seen elsewhere in Europe. The relatively clean grain deposit suggests that this sample represents processed grain ready for final food preparation and consumption at the villa. The morphological variation and overlap seen between the carbonised spelt and free-threshing wheat grains, as well as the identification of ‘stunted’ cereal grains, is also discussed.

The soft glumes of common wheat are sterile-lemmas as determined by the domestication gene Q

The Q gene in common wheat encodes an APETALA2 (AP2) transcription factor that causes the free threshing attribute. Wheat spikelets bearing several florets are subtended by a pair of soft glumes that allow free liberation of seeds. In wild species, the glumes are tough and rigid, making threshing difficult. However, the nature of these “soft glumes”, caused by the domestication allele Q is not clear. Here, we found that over expression of Q in common wheat leads to homeotic florets at glume positions. We provide phenotypic, microscopy, and marker genes evidence to demonstrate that the soft glumes of common wheat are in fact lemma-like organs, or so-called sterile-lemmas. By comparing the structures subtending spikelets in wheat and other crops such as rice and maize, we found that AP2 genes may play conserved functions in grasses by manipulating vestigial structures, such as floret-derived soft glumes in wheat and empty glumes in rice. Conversion of these seemingly vegetative organs to reproductive organs may be useful in yield improvement of crop species.

Comparing pollen and archaeobotanical data for Chalcolithic cereal agriculture at Çatalhöyük, Turkey

Establishing agricultural activity using pollen analysis is one of the prime challenges of a palaeoecological investigation. Here we report combined pollen and archaeobotanical data originating from a waterlogged off-site organic-rich fill radiocarbon dated to ∼8 ka Cal BP located between the two occupation mounds at Neolithic-Chalcolithic Çatalhöyük, south central Turkey in order to investigate the record of Early Chalcolithic agricultural activity. Pollen results indicate extremely high abundances of Cerealia-type pollen (30->70%) and critical measurements of these show them to be Triticum-type, Avena/Triticum-type, Secale-type and Hordeum-type. Pollen data are also compared with archaeobotanical data retrieved from the same sediment matrix and show high abundances of Triticum and Hordeum grains, awns, spikelet forks and glume bases. Archaeobotanical and pollen data are therefore unequivocal in showing the presence of cereals throughout the period of deposition, and although preservation of archaeobotanical cereal plant remains is typically poor, the presence of glume wheats, including emmer/‘New Type’ wheat and domesticated barley, is consistent with cereal data from on-site excavation deposits at Çatalhöyük. Pollen data also include high occurrences of clusters of Cerealia-type, Chenopodiaceae, Poaceae and Asteraceae and point to local deposition that is best explained as the anthers being deposited at the coring site attached to cereal or other herbaceous waste material. Archaeobotanical data in addition to very high percentage values of individual Cerealia-type pollen grains and clusters of Cerealia-type pollen and other non-arboreal pollen types suggest that the margins of the Çatalhöyük site were probably used for early stage crop processing activities as well as a waste site. Although radiocarbon dating of this organic-rich fill suggests that it was deposited over a very short time period (∼300 years) during the Early Chalcolithic, the data highlight the importance of adopting complementary palynological and archaeobotanical approaches in order to better understand the taphonomy of micro and macrofossil deposits associated with archaeological sites. While more distant, regional pollen sites in south-central Anatolia have difficulty registering Neolithic-Chalcolithic cereal cultivation, this study shows that if a pollen core site is located too close to an archaeological site, then pollen assemblages can be overwhelmed and ‘swamped’ by the products of local cereal processing and the inclusion of domestic waste material thus rendering it difficult to elucidate meaningful data on local agricultural activity.

Integrated proteome analyses of wheat glume and awn reveal central drought response proteins under water deficit conditions

Main conclusionIntegrated proteome analyses revealed differentially accumulated proteins in the non-leaf green organs in wheat glume and awn that play important roles in photosynthesis and drought resistance.Two non-leaf green organs in wheat, glume and awn, have photosynthetic potential, contribute to grain yield, and also play roles in resistance to adverse conditions. We performed the first integrated proteome analysis of wheat glume and awn in response to water deficit. Water deficit caused a significant decrease in important agronomic traits and grain yield. A total of 120 and 77 differentially accumulated protein (DAP) spots, representing 100 and 67 unique proteins responsive to water deficit, were identified by two-dimensional difference gel electrophoresis (2D-DIGE) in glumes and awns, respectively, of the elite Chinese bread wheat cultivar Zhongmai 175. The DAPs of both organs showed similar functional classification and proportion and were mainly involved in photosynthesis, detoxification/defense, carbon/energy metabolism, and proteometabolism. Comparative proteome analyses revealed many more drought-responsive DAP spots in glumes than in awns, which indicate that glumes underwent more proteome changes in response to water deficit. The main DAPs involved in photosynthesis and carbon metabolism were significantly downregulated, whereas those related to detoxification/defense and energy metabolism were markedly upregulated under water deficit. The potential functions of the identified DAPs revealed an intricate interaction network that responds synergistically to drought stress during grain development. Our results from the proteome perspective illustrate the potential roles of wheat non-leaf green organs glume and awn in photosynthetic and defensive responses under drought stress.

New evidence on the earliest human presence in the urban area of Genoa (Liguria, Italy): A multi-proxy study of a mid-Holocene deposit at the mouth of the Bisagno river

The article presents the results of a multi-proxy study investigating an alluvial deposit located in the coastal plain of Genoa (Liguria, Northwest Italy). A very deep core was sampled from 15 to 25 m below ground level to analyse sedimentological properties, pollen assemblages, non-pollen palynomorphs, plant macrofossils and micro-charcoal. The deposit, spanning from the second half of the 5th Millennium to the end of the 7th Millennium cal. BC, was characterized by an alternation of silty and peaty layers, and proved to be rich in plant remains. Pollen data allowed the confirmation of a gradual increase in Fagus sylvatica to the detriment of Abies alba during the mid-Holocene of the region, and showed the presence of brackish lagoons, as well as the progressively stronger incidence of anthropogenic taxa, indicating the use of the plain for agricultural purposes. The study of non-pollen palynomorphs led to the taxonomic identification of some previously unidentified types, and pointed to the occurrence of marshy environments, which were probably grazed on by domestic herbivores. Macrofossil analysis provided the first record of Triticum new glume wheat type in Liguria. Moreover, the finding of a grain of Triticum dicoccum dated to the second half of the 6th Millennium cal. BC allowed us to pre-date by seven centuries the agriculture in the region. To date, this represents the oldest evidence of human activity in the urban area of Genoa.

Early farming economy in Mediterranean France: fruit and seed remains from the Early to Late Neolithic levels of the site of Taï (ca 5300–3500 cal bc)

This article presents the archaeobotanical study of Tai, a Neolithic settlement located in Languedoc, southern France. In the western Mediterranean, the Neolithization process occurred during the 6th millennium bc and is supposed to have induced a fundamental change in the subsistence economy, with the development of agriculture and animal husbandry. Unfortunately, the Neolithic farming economy is still poorly known in southern France, mostly from old archaeobotanical studies. At Tai, soil flotation of 127 samples provided the largest dataset available for the Early Neolithic in southern France, which testifies to the changes occurring in cultivated plants and in the subsistence economy during the Neolithic. Sampling also allowed comparisons between the archaeobotanical record inside the cave and from the outside settlement. Naked barley and naked wheat were the most cultivated plants throughout the Neolithic sequence. The contribution of emmer and the probable use of opium poppy during the Early Neolithic should also be highlighted. This encourages us to reconsider the role of glume wheats during the early stages of agriculture in the area. Einkorn was more common in the Late Neolithic, in agreement with results from other sites in the region. Chaff remains were always underrepresented. Remains of weeds and wild fruits were very abundant in the Early Neolithic samples from the cave. Wild plants were probably brought to the site for the tending of domestic animals or by the animals themselves (dung, fodder and/or litter). Livestock was most probably occasionally kept at the site.

Arable weed seeds as indicators of regional cereal provenance: a case study from Iron Age and Roman central-southern Britain

The ability to provenance crop remains from archaeological sites remains an outstanding research question in archaeology. Archaeobotanists have previously identified the movement of cereals on the basis of regional variations in the presence of cereal grain, chaff and weed seeds (the consumer–producer debate), and weed seeds indicative of certain soil types, principally at Danebury hillfort. Whilst the former approach has been heavily criticised over the last decade, the qualitative methods of the latter have not been evaluated. The first interregional trade in cereals in Britain is currently dated to the Iron Age hillfort societies of the mid 1st millennium bc. Several centuries later, the development of urban settlements in the Late Iron Age and Roman period resulted in populations reliant on food which was produced elsewhere. Using the case study of central-southern Britain, centred on the oppidum (large fortified settlement) and civitas capital of Silchester, this paper presents the first regional quantitative analysis of arable weed seeds in order to identify the origin of the cereals consumed there. Analysis of the weed seeds which were present with the fine sieve by-products of the glume wheat Triticum spelta (spelt) shows that the weed floras of samples from diverse geological areas can be separated on the basis of the soil requirements of individual taxa. A preliminary finding is that, rather than being supplied with cereals from the wider landscape of the chalk region of the Hampshire Downs, the crops were grown close to Late Iron Age Silchester. The method presented here requires further high quality samples to evaluate this conclusion and other instances of cereal movement in the past.

The dead, hardened floral bracts of dispersal units of wild wheat function as storage for active hydrolases and in enhancing seedling vigor.

It is commonly assumed that the dead, hardened floral bracts of the dispersal unit of grasses have been evolved to protect seeds from predation and / or assist in fruit/caryopsis dispersal. While these structures have important agronomical and economical implications, their adaptive value has not been fully explored. We investigated the hypothesis that the maternally derived hardened floral bracts have been evolved not just as a means for caryopsis protection and dispersal, but also as storage for substances that might affect seed germination and seedling vigor. Dead glumes as well as lemmas and paleas of wild emmer wheat (Triticum turgidum var dicoccoides) were found to store and release upon hydration active hydrolases including nucleases and chitinases. High nuclease activity was released upon hydration from glumes derived from wild strains of wheat including Triticum urartu and wild emmer wheat, while very low nuclease activity was detected in glumes derived from domesticated, free-threshing wheat cultivars (e.g., durum wheat). Germination from the intact dispersal unit of wild emmer wheat was delayed, but post germination growth was better than those of separated caryopses. Most notable was a significant increase in lateral root production on seedlings germinated from the intact dispersal unit. Proteome analysis of wild emmer wheat glumes revealed many proteins stored and released upon hydration including S1-type nucleases, peptidases, antifungal hydrolases such as chitinases and β-1,3-glucanase as well as pectin acetylesterase, a protein involved in cell wall degradation and remodeling. Also, reactive oxygen species (ROS)-detoxifying enzymes such as superoxide dismutase and ascorbate peroxidase were overrepresented in dead glumes of wild emmer wheat. Thus our study highlighted previously unknown features of the dispersal unit in wild wheat in which the dead, hardened floral bracts enclosing the caryopsis store active hydrolases and nutritional elements and probably growth promoting substances that facilitate seed longevity and germination and increase seedling vigor.

Agricultural change in Copper Age Croatia (ca. 4500\u20132500\xa0cal B.C)?

The Copper Age in the Carpathian Basin is marked by a distinct change in settlement patterns, material culture, social traditions and subsistence practices; however, few studies address the nature of crop cultivation in the region. This paper examines new archaeobotanical data from 13 Copper Age (ca. 4500–2500 cal BC) sites located in continental Croatia, in order to assess the extent to which crop agriculture may have changed and contributed to overall subsistence economies in the Copper Age. From the archaeobotanical results, a dominance in einkorn and emmer is seen followed by barley. Less frequently millet, naked wheat and spelt/new glume wheat are also recovered, but due to their limited numbers, it is less clear whether they were grown as crops or represent weeds. Pulses (e.g. lentil, pea and grass pea), fruit remains (e.g. cornelian cherry and chinese lantern) and wild plant and weed species are also recovered, although more commonly from the late Copper Age sites. The archaeobotanical results show a clear reduction in the quantity and range of plant species recovered during the early/middle Copper Age; however, this is likely the result of taphonomic bias rather than a reduction in crop cultivation. The results therefore highlight problems of recovery bias in the region, which makes comparisons between sites as well as the reconstruction of crop husbandry regimes difficult. Overall, the results from continental Croatia suggest that the type of crops cultivated continued relatively unchanged from the late Neolithic, although it is clear that more research is desperately needed to explore the relationship between crop agriculture and the changing socio-economic environment of the Copper Age in the region.

Cereal chaff used as temper in loom-weights: new evidence from a Slovenian Eneolithic pile-dwelling site (ca. 3100 cal bc)

We present new evidence of the intentional use of cereal by-products at Stare gmajne, an Eneolithic pile-dwelling site in Slovenia, dated approximately 3160–3100 cal bc. The chaff material, which had been used for tempering, was discovered inside one of the largest discovered loom-weights and analysed. Clay, which was used by the dwellers to make the weight, was tempered with cereal chaff to reinforce it. The practice of tempering, not necessarily for loom weights, has already been proven for earlier settlements, mostly in arid areas where firewood, grazing and building material were scarce. However, tempering has rarely been found in European prehistoric sites. More than 1,800 carbonised and half-carbonised, excellently preserved and well identifiable cereal plant macroremains in less than 1 l of waterlogged clayey material were sorted and counted. Among the recognized plant macroremains, barley rachis fragments and glume wheat (emmer and einkorn) by-products such as spikelet forks and glume bases prevailed. A few grains were also found. Cultivation of the main crops of emmer, einkorn and barley at Slovenian Eneolithic pile-dwelling sites was confirmed again. Among the chaff, a new “strange type” of Triticum dicoccum (emmer) spikelet forks was discovered. The size of the weight and the intentional local use of cereal by-products as temper suggest that late Neolithic (Eneolithic) pile-dwelling societies all around the Alps were highly organized and developed due to expansion of crop production and processing.

Transcriptome profiling of wheat glumes in wild emmer, hulled landraces and modern cultivars

BackgroundWheat domestication is considered as one of the most important events in the development of human civilization. Wheat spikelets have undergone significant changes during evolution under domestication, resulting in soft glumes and larger kernels that are released easily upon threshing. Our main goal was to explore changes in transcriptome expression in glumes that accompanied wheat evolution under domestication.MethodsA total of six tetraploid wheat accessions were selected for transcriptome profiling based on their rachis brittleness and glumes toughness. RNA pools from glumes of the central spikelet at heading time were used to construct cDNA libraries for sequencing. The trimmed reads from each library were separately aligned to the reference sub-genomes A and B, which were extracted from wheat survey sequence. Differentially expression analysis and functional annotation were performed between wild and domesticated wheat, to identity candidate genes associated with evolution under domestication. Selected candidate genes were validated using real time PCR.ResultsTranscriptome profiles of wild emmer wheat, wheat landraces, and wheat cultivars were compared using next generation sequencing (RNA-seq). We have found a total of 194,893 transcripts, of which 73,150 were shared between wild, landraces, and cultivars. From 781 differentially expressed genes (DEGs), 336 were down-regulated and 445 were up-regulated in the domesticated compared to wild wheat genotypes. Gene Ontology (GO) annotation assigned 293 DEGs (37.5 %) to GO term groups, of which 134 (17.1 %) were down-regulated and 159 (20.4 %) up-regulated in the domesticated wheat. Some of the down-regulated DEGs in domesticated wheat are related to the biosynthetic pathways that eventually define the mechanical strength of the glumes, such as cell wall, lignin, pectin and wax biosynthesis. The reduction in gene expression of such genes, may explain the softness of the glumes in the domesticated forms. In addition, we have identified genes involved in nutrient remobilization that may affect grain size and other agronomic traits evolved under domestication.ConclusionsThe comparison of RNA-seq profiles between glumes of wheat groups differing in glumes toughness and rachis brittleness revealed a few DEGs that may be involved in glumes toughness and nutrient remobilization. These genes may be involved in processes of wheat improvement under domestication.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1996-0) contains supplementary material, which is available to authorized users.

Photochemical and antioxidative responses of the glume and flag leaf to seasonal senescence in wheat.

The non-leaf photosynthetic organs have recently attracted much attention for the breeding and screening of varieties of cereal crops to achieve a high grain yield. However, the glume photosynthetic characteristics and responses to high temperature at the late stages of grain filling are not well known in winter wheat (Triticum aestivum L.). In the present study, an experiment was conducted to investigate the anatomy, chloroplast temporal changes, chlorophyll fluorescence, xanthophyll cycle and antioxidative defense system in glumes of field-grown wheat during grain filling compared with flag leaves. Observations using a light microscope revealed that the glumes developed a solid structural base for performing photosynthesis. Compared with the flag leaves, the glumes preserved a more integral ultrastructure, as observed under transmission electron microscopy, and had higher values of Fv/Fm and ΦPSII at the maturity stage. Further analysis of the chlorophyll fluorescence demonstrated that the glumes experienced high non-photochemical quenching (NPQ) at the late stages. Determination of the pool size of the xanthophyll cycle suggested that the (A+Z)/(V+A+Z) ratio was consistently higher in glumes than in flag leaves and that the V+A+Z content was considerably higher in glumes at the maturity stage. In addition, the glumes exhibited a higher antioxidant enzyme activity and a lower accumulation of reactive oxygen species. These results suggest that the glumes are photosynthetically active and senesce later than the flag leaves; the advantages may have been achieved by coordinated contributions of the structural features, higher NPQ levels, greater de-epoxidation of the xanthophyll cycle components and antioxidative defense metabolism.

“Nor ever lightning char thy grain”1: establishing archaeologically relevant charring conditions and their effect on glume wheat grain morphology

Charring is the most ubiquitous form of preservation of plant material on archaeological sites, occurring wherever people use heat. The usefulness of preserved seeds for a range of analytical techniques is dependent on the conditions under which they were heated. In this study, we investigate the effect of experimental heating on two types of glume wheat grain (einkorn and emmer) under a range of conditions, with the intention of establishing the likely parameters for the generation of virtually undamaged, undistorted charred cereal grain on archaeological sites. The results show that grain morphology is very sensitive to the charring conditions, especially temperature, and that well preserved grains with little distortion are produced at relatively low temperatures (220–240°C). The implications of these findings for the study of grain morphology, biomolecules and chemical composition are assessed.Data availability The authors confirm that all data underlying the findings are fully available without restriction. All relevant data are contained within the paper.

Records of “new” glume wheat in France: a review

Following the first identification in 2000 of a new type of hulled wheat from three Neolithic settlements and a Bronze Age one in Greece, many finds of this “new” glume wheat have been reported from all over Europe and the Near East. In France, a first identification in 2009 also triggered several discoveries. Up to now, twelve sites have delivered remains of this new type, from different phases of occupation, located in the eastern half of France. Their chronology ranges from Neolithic Linearbandkeramik to late Bronze Age/early Iron Age transition (5300–800/700 bc). At most of the sites, the “new” glume wheat appears as a minor contaminant of other cereal crops. However, at the early Bronze Age settlement of Clermont-Ferrand, central France, the recovery of large quantities of caryopses and spikelet bases has demonstrated that the “new” glume wheat was a crop by itself, maybe mixed with emmer and other cereals. For the late Bronze Age, numerous records of the new type come from the upper Seine valley, north-eastern France. At four settlements with early phases of the late Bronze Age, the “new” glume wheat was also a crop in its own right, within a much diversified agricultural system. In the light of the numerous archaeobotanical analyses carried out on Bronze Age sites in France, and despite the fact that its presence is surely underestimated, cultivation of the “new” glume wheat appears to have been a speciality, restricted to a few places. It may have come from a local agricultural choice, but it could also have resulted from eastern influences and exchanges that were very active during the Bronze Age.

Occurrence of mycotoxins in spelt and common wheat grain and their products

Organic farming does not allow the use of conventional mineral fertilizers and crop protection products. As a result, in our experiments we chose to grow different species of cereals and to see how cereal species affect mycotoxin accumulation. This study describes the occurrence of deoxynivalenol (DON), zearalenone (ZEA) and T-2/HT-2 toxin in a survey of spelt and common wheat and their bran as well as flour. The analysis was conducted using an enzyme-linked immunosorbent assay (ELISA) method. The concentrations of DON, ZEA and T-2/HT-2 in Triticum spelta and T. aestivum were influenced by species, cereal type and year interaction. The highest concentrations of these mycotoxins were found in spelt grain with glumes, in spelt glumes and in spring wheat. These results show significantly higher concentrations of Fusarium toxins in glumes than in dehulled grain, which indicates the possible protective effect of spelt wheat glumes. The lowest DON, ZEA and T-2/HT-2 concentrations were determined in spelt grain without glumes. The research shows that it is potentially risky to produce bran from grain in which mycotoxin concentrations are below limits by European Union Regulation No. 1881/2006, since the concentration of mycotoxins in bran can be several times higher than that in grain. As a result, although bran is a dietary product characterised by good digestive properties, it can become a harmful product that can cause unpredictable health damage.

Evidence of ‘new glume wheat’ from the Late Neolithic (Copper Age) of south-eastern Hungary (4th millennium cal. b.c.)

In 2000, remains of an unknown Triticum species—later named ‘new glume wheat’ (NGW)—were identified in the archaeobotanical material of Neolithic and Bronze Age Greek sites. The presence of NGW was later reported from several other locations across Europe, from the seventh to the first millennium cal. b.c. During the systematic archaeobotanical survey of the multiperiod site of Hodmezővasarhely–Kopancs I., Olasz-tanya (5310–2936 cal. b.c.) more than 2,000 cereal remains were recovered. During the morphological analyses, ten spikelet forks showed the distinctive traits of NGW, therefore morphometric analyses were conducted on the remains to reinforce the morphological identification. The results suggest that both approaches—morphological and morphometric—should be applied in parallel to securely separate the NGW remains from Triticum turgidum L. ssp. dicoccum (Schrank) Thell. (emmer) and T. monococcum L. ssp. monococcum (einkorn). All NGW glume bases were recovered from Late Copper Age features (3338–3264 cal. b.c.) of the settlement, which represent the Baden culture of the Great Hungarian Plain. Similarly to other Baden culture sites of the Carpathian Basin einkorn and emmer dominated the crop production of the settlement. The ratio of the NGW remains within the cereal assemblage was measured to be 0.48 %, which suggests that NGW did not have the status of a regular crop; still it may have been part of the accompanying weed flora of the cereal fields during the fourth millennium in the south-eastern Great Hungarian Plain landscape.

Towards a distinction between digested and undigested glume bases in the archaeobotanical record from Neolithic northern Greece: A preliminary experimental investigation

This study investigates the possibility of distinguishing digested from undigested glume wheat chaff in the archaeobotanical record. To this end the contents of dung pellets collected from a goat fed on einkorn spikelet forks and glume bases are analysed and the derived einkorn chaff examined macroscopically with the aid of scanning electron microscopy. The modern dung pellets contained recognisable glume bases which, compared with undigested ones, demonstrated a ‘rugged’ surface. When these dung pellets were charred, glume bases were still preserved in them. The experimental pellets show that dung can contribute glume bases in archaeobotanical assemblages and that these glume bases may be distinguishable from those derived from glume wheat dehusking by-products used as fuel. These results need to be further explored on archaeobotanical materials. Moreover, further experimentation with different charring regimes, as well as the examination of more experimental specimens is needed.

Quantifying the relationship between temperature regulation in the ear and floret development stage in wheat (Triticum aestivum L.) under heat and drought stress.

Thermal imaging is a valuable tool for the clarification of gas exchange dynamics between a plant and its environment. The presence of stomata in wheat (Triticum aestivum L.) glumes and awns offers an opportunity to assess the photosynthetic activity of ears up to and during flowering. Knowledge of the spatial and temporal thermodynamics of the wheat ear may provide insight into interactions between floret developmental stage (FDS), temperature depression (TD) and ambient environment, with potential to use these as high-throughput screening tools for breeders. A controlled environment study was conducted using six spring wheat genotypes of the elite recombinant inbred line Seri-Babax. Average ear temperature was recorded using a hand-held infrared camera and gas exchange was measured by enclosing ears in a custom-built cuvette. FDS was monitored and recorded daily throughout the study. Plants were grown in pots and exposed to a combination of two temperature and two water regimes. In the studied wheat lines, TD varied from 0.1°C to 0.6°C according to the level of stress imposed. The results indicated that TD does not occur at FDS F3, the peak of active flowering, but during the stages before pollen release and stigma maturity (F1-F2). These findings suggest that ear temperature during the early stages of anthesis, before pollen release and full extension of the stigma, are likely to be the most relevant for identifying heat stress tolerant genotypes.

THE ARCHAEOBOTANICAL EVIDENCE OF THE LATE BRONZE AGE AND PROTOGEOMETRIC OCCUPATION UNDER THE ROMAN VILLA DIONYSUS, KNOSSOS, CRETE, AND AN OVERVIEW OF THE PROTOGEOMETRIC DATA OF GREECE

Archaeobotanical material was collected from the Bronze Age fill and the Protogeometric phases underneath the Roman Villa Dionysus, Knossos, Crete. The Bronze Age assemblage was poor, representing only accidental intrusions to a tight fill of sherds and stones. The Protogeometric data were more plentiful, providing a rare glimpse into the everyday life of the period. Glume wheat, barley, legumes, fruits, nuts and several wild species were present across two Protogeometric floors. No significant differences were observed in their spatial and temporal distribution. The plant remains, along with other bio-archaeological classes of material, indicated a series of domestic activities, including cooking and consumption events, the remnants of which gradually accumulated in the habitation floors. The archaeobotanical evidence from Villa Dionysus was then compared with other Protogeometric Cretan and Greek mainland sites. An overview of these sites allowed some general trends to be observed, tentatively suggesting a picture more similar to Bronze Age than Iron Age archaeobotanical assemblages. It also highlighted differences, which would both dictate and be shaped by different socio-economic systems, and the need for more contextualised studies.