Thèses sur le sujet « Ancient wheat »

Modern bread wheat (Triticum aestivum) initially derived from wild progenitors which underwent hybridisation and domestication events. It is hypothesised that modern plant breeding has reduced the genetic variation among modern cultivars (Sparkes, 2010). Ancient wheat species form a conduit between wild ancient wheat and cultivated Triticum species, and may harbour the genetic variation required to supplement the modern bread wheat gene pool. The current work investigated a range of morphological and physiological aspects of several ancient species including several representatives of spelt, emmer and einkorn. These were compared to modern bread wheat in two field and three glasshouse experiments with the aim to investigate their resource use efficiency, where radiation use and water use formed the crux. The main components of the current work relate to 1) canopy interception characteristics 2) leaf photosynthetic capabilities and 3) water use. Spelt genotypes demonstrated increased WUE and green area longevity compared with modern bread wheat. Emmer displayed increased WUE, assessed on three scales using instantaneous transpiration efficiency (ITE), biomass to water uptake ratios, and carbon isotope discrimination (Δ13C). In addition, the mechanisms whereby emmer, einkorn and spelt maintained ITE appeared to differ. Emmer was observed to increase photosynthetic rates, whereas spelt maintained low transpiration as a result of low stomatal conductance. Einkorn however, maintained ITE through an intermediate of both of these mechanisms. This was further supported by species differences for maximum photosynthetic rates (Asat) which, for emmer and einkorn, were comparable with modern bread wheat. Investigation of WUE through Δ13C and biomass production to water uptake ratios ranked species similarly, showing emmer and spelt to have superior WUE during grain filling. Additionally, spelt was observed to produce biomass comparable to modern bread wheat, thought to be due to enhanced RUE (observed in one field trial) or increased green area longevity rather than increased assimilation capability. In field experiments, biomass production and light interception was relatively high for einkorn species, however this was believed to derive from excessive tiller production due to poor emergence. Overall, ancient species did partition a larger proportion of assimilates toward tillers. Modern bread wheat produced fewer tillers, but directed more biomass towards the ear, and therefore had greater harvest indices (HI) compared to all ancient species. Despite this broad analysis, further investigation of the mechanisms responsible for these traits is required. This research therefore indicates that there is sufficient variation for traits, which could be used to improve radiation and water use efficiency, and therefore warrants further exploration. With further investigation, resource capture and utilisation efficiency, and the morphological traits that confer these advantages in these genotypes, genetic markers could be identified with the aim to introduce valuable traits for the production of novel modern bread wheat varieties. The differences observed between these ancient wheat species and modern bread wheat provide an opportunity through which modern wheat gene pools may be improved to stabilise yields, particularly in sub-optimal environmental conditions, thus increasing biomass production per unit resource, thereby enhancing the productivity and the efficiency of crop systems.

Nitrogen (N) fertiliser is one of the main inputs of intensive wheat cropping systems in the UK. The average application of N fertiliser in the UK for winter wheat was 220 kg N ha-1 in 2011, but typically only 50% of this applied N is taken up by the crop. Breeding crops for high N use efficiency (NUE; grain dry matter yield per unit availability of N from soil and/or fertiliser) while maintaining acceptable yield, is widely accepted as one of the approaches to maximise farmers’ revenue and minimise pollution risk by reducing N fertiliser application. NUE is divided into two components; N uptake efficiency (NUpE; crop N uptake per unit availability of N from soil and/or fertiliser) and N utilisation efficiency (NUtE; grain dry matter yield per crop N uptake). NUE can be improved by improving NUpE and /or NUtE. Targeted integration of favourable traits into breeding programmes needs adequate diversity of the existing genotypes. However, genetic diversity of modern bread wheat is narrowed due to chance hybridisation events during wheat evolution and selective breeding for high yield. Hence, it has become necessary to search for novel sources of genetic variation for NUE. One of the sources could be the ancient wheat species, which provide novel resources of genes to improve NUE of modern bread wheat. The overall objective of the current project is to explore favourable physiological traits for NUE in ancient wheat species. Three field experiments, four glasshouse experiments and three growth room experiments were conducted at Sutton Bonington Campus, University of Nottingham. The current work can be divided into four main components; (i) investigation of general plant growth and development, (ii) quantification of NUE and its components, (iii) exploration of root architectural traits of seedlings and mature plants, and (iv) identification of seedling root QTLs related to NUpE in a wheat x spelt population. Significant variation for plant establishment and development was identified among wheat species where bread wheat had high plant establishment and faster plant development compared to ancient wheat species. Above ground biomass production of bread wheat, spelt and emmer was either similar or bread wheat was slightly higher at maturity under high N levels (HN). However, high above ground biomass production at zero N (no N fertiliser; NN) was observed in spelt genotypes. High grain yield of bread wheat is due to improved harvest index when compared to tall ancient wheat species. Delayed onset of flag leaf senescence, slow senescence rate and prolonged leaf greenness were observed in some spelt genotypes, especially spelt cv. Oberkulmer and were positively associated with biomass production. Flag leaf length, width, green area, specific leaf area and SPAD values were significantly different between genotypes used in the study. The greatest green area, SPAD value and maximum width were recorded in bread wheat. NUE was higher in bread wheat followed by spelt, emmer and einkorn. Emmer 2 had higher NUpE than spelt, bread wheat and einkorn genotypes. Delayed senescence hence extended green area duration and deep and vigorous root system might have influenced NUpE of spelt genotypes. High fertiliser N recovery rate of emmer 2 may be associated with well distributed, shallow, horizontally grown root system, especially at early plant growth. NUtE of bread wheat is higher than ancient wheat species and closely related to harvest index and reduced plant height. NUtE is more controlled by genetic factors than NUpE. N supply has a negative relationship with NUpE and its components. Relationships between NUE and its components were not consistent between experiments in the study. However, NUpE and NUtE explained more of the variation in NUE under HN than NN. Root system architecture varied significantly between wheat species used in the study. Seminal root characters of the seedling such as tip angle, number of seminal roots, seminal root length and total root length are closely related to mature root systems. Spelt had long seminal roots with narrow tip angles and hence develops deep root system while having a well-developed superficial root system due to nodal roots. Therefore, both top soil scavenging and deep soil foraging occurs efficiently. A large and deep root system contributes significantly to greater above-ground biomass and green area production of spelt. A greater number of seminal roots with wide tip angles help emmer to develop a root system architecture well adapted to take up fertiliser N from the top soil layers, especially in early stage of the plant growth. There is a possibility of using seedling root traits such as total root length and average length of the seminal root to predict NUpE at maturity. Therefore, these traits might be used as selection criteria for crop breeding for efficient N uptake. Emmer had favourable seedling root traits related to NUpE while spelt showed more favourable root traits at for N uptake at maturity than modern bread wheat and einkorn. Root N uptake efficiency and specific absorption rate of N were higher in emmer than spelt, bread wheat and einkorn. Phenotypic evaluation and genetic analysis of recombinant inbred lines (RILs) produced from the cross between Swiss winter wheat variety Forno (Triticum aestivum) and Swiss winter spelt cv. Oberkulmer (T. spelta) was carried out. Two parents of the population were significantly different for a number of traits, including: number of seminal roots, average length of seminal roots, total root length, maximum width, width to depth ratio, tip angle and emergence angle of seminal root. All measured root traits of seedlings of the RILs varied significantly. A total of 26 significant QTLs were identified for seedling root traits. These QTLs were located on ten different chromosomes; 1BS, 2A, 2D, 3A, 3B, 4A, 5A, 5B, 7AL and 7D. QTL coincidence was found for total root length either with number of seminal roots or seminal root length of the seedlings which showed strong phenotypic relationship. RILs F5-10, F5-36, F5-134, F5 146, F5-230 and F5-234 could be efficient genotypes for N uptake at maturity. The contribution of the A genome to the phenotypic variation observed within this cross for the development of the seedling root system is more important than the B and D genomes, as assessed by QTL analysis. Further studies are needed to identify QTLs associated with NUpE and root architectural traits of emmer and spelt. Favourable root traits in emmer and spelt related to NUpE could be introduced to bread wheat through direct crossing or creating synthetic wheat. The introgression of spelt into modern bread wheat will be useful for molecular studies to develop marker assisted breeding for high NUpE.

Ancient DNA analysis of archaeological wheat remains may serve to clarify unknown or controversial points in the history of wheat. In the first part of this study, extraction and amplification of DNA from Anatolian charred ancient wheat seeds obtained from different locations and ages was attempted. None of the our extraction samples yielded any PCR amplification. The possible reasons for this result were investigated by constructing an artificial charring experiment. The results suggest that the chances of obtaining DNA from the charred archaeological samples used in this study by the methods used are very low. Moreover, strong PCR inhibition by these charred seed extracts was observed. The second part of the study aimed to develop new DNA based markers for ancient wheat DNA analysis. Markers linked to the brittle rachis character exhibiting domestication status were sought, but no result was obtained. Primers targeting plasmon sequences were developed and tested. A primer pair amplifying a 400 bp portion of the chloroplast TrnLTrnF intergenic region was focused upon. A short piece of this region was amplified using ancient wheat DNA extracted in another study. This short piece appeared non-polymorphicupon sequencing. The sequence spanning a wider portion of this region contained a number of length polymorphisms. Phylogenetic reconstruction using maximum parsimony showed that these polymorphisms were able to distinguish wheat taxa at the maternal ancestor level.

This thesis explores Aristotle's theories of habituation and voluntariness and their impact on his ability to attribute moral responsibility to agents. Ultimately, I conclude that Aristotle should drop his assertions that we are morally responsible for our states of character in order to accommodate a compatibilist view that will still allow him to attribute moral responsibility for action to agents.

It is true that the music of antiquity is now mute, but archaeology has provided valuable artifacts pictorial representations showing musical activity and musical instruments of the ancient world. Several scholars have conducted paramount research regarding music from every period in the ancient Near East, and contributed greatly to the field. Further study, however, is required. This paper presents new questions to previously studied Near Eastern musical artifacts and iconography. These queries explore the areas of identifying instruments in artifacts and iconographic depictions, performance techniques, gender identification of musicians in depictions, and the use of space in cultic activities involving music. The goal of this study is to shed additional light and generate further discussion in these areas of musical activity in the Ancient Near East. As expected, this study is difficult. Nevertheless, these questions must be addressed in an effort to better understand music activity in ancient Israel/Palestine and surrounding Near Eastern cultures.

In this thesis I try to answer the question of what attitude the ancient sceptics had towards the notion of belief. I concern myself exclusively with Pyrrhonic scepticism, as it was described by Sextus Empiricus in his book Pyrrhoniai hypotyposeis. Pyrrhonic scepticism was an epistemological system with ethical ramifications, that questioned most of the conventional wisdom of the time, I begin by evaluating two infleuntial readings, by Michael Frede and Casey Perin. I then go on to make my own assessment. Ultimately, I show why Frede's view is the more plausible; the sceptics allowed themselves to hold beliefs about reality, not just appearance.

This thesis wants to say that Socrates was a teacher of his fellows. He engaged with them through dialogue because he cared for their wellbeing, or as he might have put it: for the state of their souls. He was an intellectual and he had an intellectualist view of people and reality. He felt that right-mindedness was reasonable; and thus he believed that learning and developing understanding brought people closer to being virtuous; to goodness; and so to mental health. Socrates was a philosopher, and he considered this to be the most prudent and exalted approach to life. He taught his fellows how to be philosophers, and he urged them as best he could to take up the philosophical stance. His form of care for others was ‘intellectualist’. He cared ‘for the souls of others’ and for his own with intellectual involvement because he believed that this was the most appropriate way. He had a view of the human soul that produced intellectualist views of what wellbeing is and how it is achieved. He himself was a humble and able thinker, and was fully devoted to being virtuous and to helping his fellows to do the same. This thesis addresses the question of what Socrates did in the agora (his aims) and how he went about doing it (his methodology). Our answer might seem obvious. One might wonder what is new about saying that Socrates was a philosopher, and that he cared for the souls of his fellows and that he urged them to become virtuous. Perhaps nothing of this is new. Nevertheless, we find that making this ‘simple’ statement about Socrates is not that simple at all. We find that in Socratic scholarship there exist a plethora of contrasting voices that make it rather difficult to formulate even such a basic description of what Socrates did. We do not wish to create a novel and different reading of Socrates. We do not think that this is even possible after civilization has been interpreting Socrates for millennia. We do not see innovation for its own sake as desirable. We prefer clear understanding to the eager ‘originality’. Therefore rather, our aim with this work is to defend and clarify a very basic picture of Socrates as an educator. We see this work as clearing away clutter so as to begin our life-long study of Socratic thought and action: by laying a foundation with which we can read Socratic works and discern their meaning.

Even though the analysis of DNA from archaeological bone comes with some major limitations, it constitutes the most directmeans of investigating prehistoric population dynamics. The interdisciplinary contextualization of genetic data with the archaeological and palaeoecological record helps to reconstruct past population histories and the demography of ancient populations. For South America, palaeogenetic studies have become increasingly important. Here we review the existing ancient DNA data from pre-Columbian individuals to assess their potential to contribute to our understanding of early South American population history. The spatial and temporal distribution of ancient South American populations analysed to date is very uneven and the data resolution of the analysed genetic markers is low. Nevertheless, the data suggest that there were population dynamic processes accompanying cultural development in Western South America. With the new methodologies and better sampling strategies employed in current paleogenetic projects and more effective interdisciplinary cooperations it will be soon possible to achieve a better understanding of the peopling of the continent and the succeeding population history.
Aún cuando el análisis de ADN de huesos arqueológicos tiene algunas grandes limitaciones, constituye la manera más directa de investigar eventos prehistóricos de dinámica poblacional. La contextualización interdisciplinaria de los datos genéticos con los registros arqueológico y paleoecológico permite reconstruir las historias poblacionales pasadas y la demografía de sociedades antiguas. Por otro lado, el número de estudios paleogenéticos en Sudamérica se está incrementando. En este artículo revisamos los datos de ADN antiguo de individuos prehispánicos que existen en la actualidad con la finalidad de evaluar su potencial para contribuir a nuestro entendimiento de la historia temprana del poblamiento de Sudamérica. La distribución espacial y temporal de las poblaciones sudamericanas antiguas muestreadas a la fecha es muy irregular y la resolución de los marcadores genéticos analizados esbaja. Sin embargo, los datos sugieren que existieron procesos de dinámica poblacional que acompañaron el desarrollo cultural de la parte oeste de Sudamérica. Con las nuevas metodologías y mejores estrategias de muestreo que se emplean hoy en día en los proyectos de paleogenética, y con una cooperación interdisciplinaria más efectiva, pronto será posible lograr un mejor entendimiento del poblamiento del continente, así como de los hechos sucesivos de su historia poblacional.

The design of cultural centre is situated in part Kozia Hôrka( well-known city swimming pool), in its advantage takes natural scenery and calm atmosphere of place. Into action of performance brings a message in form of body of reservoir, function of centre is divided into small parts placed in area Kozia Hôrka. Orientation of objects comes mainly from local natural ispirations. Complex is multifunctional in concept, counts with several sorts of culture - sports events. Whereby the main function of swimming pool is preserved and added for higher comfort of inhabitants. Architecture of objects comes from idea of floating leaf on water level and body of reservoir. Objects stylizely illustrate this idea. The design takes the game of solids of organic and strictly ortogonal shapes. Two mutual opposites, in interaction. Objects smoothy and with respect encroach the environment, which is enough marked by human. Simplicity in used materials ( glass, steel, wood ) give transparency and purity to whole solution.

This work aims to explore the use of genetic sequences sampled serially through time (heterochronous data), to infer the timescale of past evolutionary events. Such data can be generated from preserved sub-fossil or fossil organismal remains (like mummified tissues, fossilized bones or coprolites), and then used to observe genetic modifications in real-time. Most importantly, the dates of the samples provide firm temporal tie points for their genetic sequences, and can be used to calibrate phylogenetic reconstructions. This thesis presents several case studies where ancient DNA was used to re-calibrate evolutionary timescales. In every situation, the use of heterochronous data led to elevated molecular rate estimates, resulting in the reconstruction of younger timescales, as compared to estimates based on fossil calibrations. These observations are in agreement with the recent demonstration that molecular rates vary according to the time period over which they are calculated. This work shows that, ancient DNA offers crucial temporal information to reliably estimate the timescale of recent population evolution, and is generally the only source of direct calibration available for this specific timeframe. Along with the results specific to each organism studied (hyena, bison and human), an emphasis was placed on the methodological aspects of the use of ancient DNA to generate timed phylogenetic inferences. Additionally, simulated data and mathematical modelling were used to extend the understanding of specific aspects of the temporal dependence of molecular rates. The results discussed in the present study help to further elucidate the evolutionary mechanisms behind the molecular clock concept, and have implications for the development and application of statistical models to obtain accurate time estimates from genetic data.
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2012