Grain nitrogen (N) concentration is a major quality criterion of malting barley for which there is a narrow range that producers must meet to satisfy market requirements (1.52 – 1.84 %). In recent years growers in Ireland have had difficulty producing grain with a high enough N concentration to meet these requirements using standard recommended agronomic regimes. The reasons for the lower than expected grain N concentrations are not known. There is interest from growers and maltsters in the development of a system to forecast likely grain N concentration from crop measurements made at or before flowering. A forecasting system would allow growers to identify crops at risk of falling below specification and to apply late N fertiliser if needed. It would also enable maltsters to plan grain intake and malting operations in advance of harvest. The aim of this project was to investigate the potential for predicting grain N concentrations of spring barley from crop and soil measurements made at ear emergence. The main objectives were to 1) investigate the relationships between measurements made at ear emergence and grain N concentration at harvest in order to identify which characteristics should be included as variables in multiple regression models to explain variation in grain N concentration, 2) to use the models with independent data sets to predict grain N concentration and test the accuracy of the predictions, 3) to quantify the recovery by the crop of fertiliser N applied at anthesis and its effects on grain N concentration and 4) to determine whether non-destructive techniques can provide estimates of crop growth and N content for use in the prediction models. Field experiments were established with plots of spring barley (Hordeum vulgare cv. SY Taberna) at one site in 2013 and two sites in 2014 representative of those employed in malting barley production in Ireland. Fertiliser N applications were varied over the range 0 – 210 kg N/ha (with dressings split between sowing and mid-tillering) to provide a range of crop growth and grain N concentrations. In some experiments additional applications of N were made at anthesis to quantify effects on grain N concentration and seed rate treatments (150, 300 and 600 seeds per m-2) imposed to test the accuracy of predictions of grain N concentration in crops of varying canopy structure. Destructive samples were taken to determine total crop N content and canopy N distribution at ear emergence and harvest. Measurements of soil mineral N availability, ear numbers per m-2 and the number of spikelets per ear were made at ear emergence. Final grain yield and quality were also determined at harvest. Grain N concentration is the quotient of grain N content and grain yield. Both grain N content and yield explained a significant amount of the variation in grain N concentration observed across sites and fertiliser N treatments indicating that estimates of both must be included in models to predict N concentration. Grain N content was strongly related to total crop N content at harvest (P < 0.001; R2 = 0.96), which in turn was related to canopy N content at ear emergence (P < 0.001; R2 = 0.94). Similarly, grain yield was strongly related to total crop biomass at harvest (P < 0.001; R2 = 0.83), which in turn was related to crop biomass at ear emergence (P < 0.001; R2 = 0.88). These results indicated that predictions of grain N concentration might be possible from measurements of crop N content and biomass at ear emergence and that the effects of variation in harvest index, nitrogen harvest index and post-anthesis N uptake on grain N concentration are likely to be negligible under normal agronomic conditions in Ireland. Weather conditions in 2013 were unusually dry and estimates of soil moisture deficit and available water capacity indicated that the crop was water stressed. In 2014 weather conditions were close to the long term averages for the sites. Multiple regression models using canopy N content and biomass at ear emergence as explanatory variables accounted for 91% of the variation in grain N concentration when data from 2014 were used and 80% when data from both 2013 and 2014 were combined. The models developed using data from plots sown at 300 seed per m-2 in 2014 were tested against independent data from plots sown at 150 seeds per m-2 in the same year and at the same sites to test the accuracy of predictions across plant populations and canopy structures. The models were also tested using data from experimental plots and commercial fields collected in 2015 to test the accuracy of predictions in a different year across a range of sites and varieties. Values of grain N concentration predicted from measurements at ear emergence were compared with actual grain N concentrations measured at harvest. The accuracy of predictions was good with an R2 of 0.80 and RMSE of 0.114 %N for the test across seed rates and R2 of 0.80 and RMSE 0.220 %N for the validation in 2015 across sites and varieties. In 2014, grain N concentrations were increased significantly by applications of additional N fertiliser at anthesis with apparent recoveries (increase in N content (kg) /kg fertiliser N applied) in grain averaging 50% over the range of application rates indicating scope for increasing grain N concentration in crops predicted to be at risk of not meeting malting specifications Non-destructive measurements displayed significant relationships with N content and biomass at GS 59 across a combination of sites and seasons. However, issues in performance relating to instrument saturation were obvious and estimates never produced more accurate predictions of grain N concentration than destructive sampling. The results show that grain N concentration of spring barley can be predicted with good accuracy from measurements of canopy N and crop biomass made at ear emergence when the weather conditions are comparable to the long term average for the region. As conditions of drought are rare in Ireland, the prediction models are a potentially valuable tool to aid crop management and post-harvest operations by growers and maltsters. Further testing will be needed before users can be confident in the reliability of predictions over years and a larger set of varieties.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study aimed to evaluate the effects of adding protein sources coming from the pumpkin seed in growth, activity of proteolytic digestive enzymes and metabolic responses of silver catfish (Rhamdia quelen) fed with increasing replacement of fishmeal by pumpkin seed meal (PSM) or phosphorylated protein concentrate of pumpkin seed (PPCPS). For the development of protein concentrate, the method was optimized by statistical methodology of response surface (MRS) and central composite rotational design (CCRD). The CCRD pointed as the highest yield 50.04%, using 4% sodium trimetaphosphate (STMP) at pH 4.5. Those same experimental conditions the protein content was 62.56%. Subsequently, the PSM and PPCPS were used as substitutes in silver catfish protein diets. For eight experimental weeks, 400 silver catfish, with a body mass of 24 ± 0.46 g were divided into 24 fiber glass, fed five experimental diets in four replicates. For the data, four orthogonal contrasts were applied: Control Diet vs. PSM Diets, Control Diet vs. PPCPS Diets, Control Diet vs. Other Diets and PSM Diets vs. PPCPS Diets. Treatment groups replaced 25 to 50 percent protein fishmeal by PSM and PPCPS. Silver catfishes were evaluated for growth parameters, digestive indices, activities of digestive enzymes trypsin and chymotrypsin, as well as metabolic parameters in plasma and liver. The fish growth parameters showed a significant difference (P <0.05) for final body weight at the end of the trial period in contrast Control Diet vs. PSM Diets. Feed conversion was higher for fish that received 25% or 50% PPCPS than those that received PSM (P <0.05). The fish receiving the Control Diet had the lowest digestive-somatic index in contrasts Control Diet vs. PPCPS Diets and Control Diets vs. Other Diets. The control fish treatments showed lower activity of trypsin and chymotrypsin enzymes than fish fed the PSM diet (P <0.05). Also, less chymotrypsin activity was observed in the fish that received the PSM diet (P <0.05), in contrast PSM Diets vs. PPCPS Diets. The fish that received the PPCPS Diets had higher protein efficiency rate than fish fed the FSA (P <0.01). For albumin in plasma, low contents were found in fish that received Control Diet (P <0.05). The ALAT activity was high in fish that received Control Diet (P <0.05), in contrasts Control Diet vs. PSM Diets, Control Diet vs. PPCPs Diets and Control Diet vs. Other Diets. The ALP was most active in fish that received the PPCPS diets (P <0.05), in contrasts Control Diet vs. PPCPS Diets and Control Diet vs. Other Diets. Thus, it can be concluded that the replacement of fishmeal protein by 25 or 50% PPCPS not alter growth and improve the feed conversion catfish and protein efficiency ratio, without affecting the activity of digestive enzymes, metabolic parameters intermediate and liver of silver catfish, can be used in silver catfish nutrition. / O presente estudo teve como objetivo avaliar os efeitos da adição de fontes proteicas advindas da semente de abóbora no crescimento, atividade de enzimas digestivas proteolíticas e respostas metabólicas de jundiás (Rhamdia quelen) alimentados com substituições crescentes de farinha de peixe por farelo de semente de abóbora (FSA) ou concentrado proteico fosforilado de semente de abóbora (CPPFSA). Para o desenvolvimento do concentrado proteico, o método foi otimizado pela metodologia estatística de superfície de resposta (MSR) e delineamento central composto rotacional (DCCR), que apontou como maior rendimento 50,04%, utilizando 4% de trimetafosfato de sódio (STMP) em pH 4,5. Cujo conteúdo proteico foi 62,56%. Posteriormente, o FSA e o CPPFSA foram utilizados como substitutos proteicos nas dietas de jundiás. Durante oito semanas experimentais, 400 jundiás, com massa corporal de 24 ± 0,46 g foram distribuídos em 24 caixas, alimentados com cinco dietas experimentais em quatro repetições. Para análise dos dados, quatro contrastes ortogonais foram aplicados: Dieta Controle vs.. Dietas FSA, Dieta Controle vs.. Dietas CPPFSA, Dieta Controle vs.. Demais dietas e Dietas FSA vs.. Dietas CPFFSA. Os grupos de tratamento substituíam 25 e 50 por cento de proteína da farinha de peixe pelo FSA e CPPFSA. Foram avaliados parâmetros de crescimento, índices digestórios, atividades das enzimas digestivas tripsina e quimotripsina, bem como parâmetros metabólicos em plasma e fígado. Os parâmetros de crescimento dos peixes mostraram diferença significativa (P < 0,05) para massa corporal final ao final do período experimental no contraste Controle vs. dietas FSA. A conversão alimentar foi superior para os peixes que receberam 25% ou 50% CPFFSA em comparação àqueles que receberam FSA (P < 0,05). Os peixes que receberam a dieta Controle apresentaram menor índice digestivo-somático nos contrastes Controle vs. dietas CPFFSA e Controle vs. demais dietas. A atividade das enzimas tripsina e quimotripsina foram menores nos peixes do tratamento Controle, quando comparada aos peixes que receberam as dietas FSA (P < 0,05). Menor atividade de quimotripsina também foi observada nos peixes que receberam as dietas FSA (P< 0,05), no contraste dietas FSA vs. dietas CPFFSA. Os peixes que receberam as dietas CPPFSA apresentaram maior taxa de eficiência proteica do que os peixes que receberam dietas contendo FSA (P< 0.01). Para albumina no plasma, os menores conteúdos foram encontrados nos peixes da dieta Controle (P<0.05). A atividade da enzima ALAT foi maior nos peixes que receberam a dieta Controle (P<0.05), nos contrastes dieta Controle vs. dietas FSA, dieta Controle vs. dietas CPFFSA e dieta Controle vs. demais dietas. A ALP apresentou maior atividade nos peixes que receberam as dietas CPFFSA (P<0.05), considerando os contrastes dieta Controle vs. dietas CPFFSA e dieta Controle vs. demais dietas. Dessa maneira, pode-se concluir que a substituição da proteína da farinha de peixe por 25% ou 50% de CPFFSA não altera o crescimento e promove melhoria na conversão alimentar de jundiá e taxa de eficiência proteica, sem prejudicar atividade de enzimas digestivas, parâmetros metabólicos intermediários e hepáticos dos jundiás, podendo ser utilizado na nutrição do jundiá.

Submitted by TAILENE ELISA KOTZ null (taileneelisa@hotmail.com) on 2016-05-31T21:04:37Z No. of bitstreams: 1 Tese_Tailene_E_K_Gurgacz_FINAL.pdf: 1143646 bytes, checksum: 87259b3c2df0880c1b4c49bc2dca3f6c (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-06-01T16:14:02Z (GMT) No. of bitstreams: 1 gurgacz_tek_dr_bot.pdf: 1143646 bytes, checksum: 87259b3c2df0880c1b4c49bc2dca3f6c (MD5) / Made available in DSpace on 2016-06-01T16:14:02Z (GMT). No. of bitstreams: 1 gurgacz_tek_dr_bot.pdf: 1143646 bytes, checksum: 87259b3c2df0880c1b4c49bc2dca3f6c (MD5) Previous issue date: 2016-05-06 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O uso de fertilizantes de liberação lenta ou controlada é colocado como eficiente para agricultura, pois fornece nutrientes de forma regular e contínua, de acordo com a necessidade das plantas. Porém, pouco se sabe sobre uso dessas fontes na cultura do feijão comum (Phaseolus vulgaris L.). Dessa forma, objetivou-se avaliar o efeito da utilização de fontes de nitrogênio (N) via foliar, em diferentes estádios de desenvolvimento da planta, sobre a produtividade e qualidade de grãos da cultura do feijão comum, cultivado na presença e ausência da aplicação de N via solo. Para tanto, foram realizados seis experimentos, sendo, dois em condições de campo (experimentos I e II) e repetidos em três condições (ambiente I, II e III). Os experimentos de campo foram realizados nas safras “das águas” e “da seca” do ano agrícola 2012/13 e instalados em blocos casualizados. O experimento I foi constituído por 20 tratamentos, sendo a combinação de quatro doses de N em cobertura (0, 45, 90 e 180 kg ha-1) e cinco tratamentos com aplicação de N via foliar (1 - testemunha - sem aplicação de N via foliar; 2 - 2,5 kg ha-1 de N na forma de ureia (UC); 3 - 5,0 kg ha-1 de N-UC; 4 - 2,5 kg ha-1 de N na forma de ureia-formaldeído (UF - Coron®); 5 - 5,0 kg ha-1 de N-UF). Já o experimento II foi constituído por 12 tratamentos, sendo, quatro doses de ureia-formaldeído (0, 1,25, 2,5 e 5 kg ha-1) para fornecimento de N via foliar e três épocas de aplicação [1 - estádio V4 (três folhas trifolioladas completamente expandidas), 2 - estádio R5 (pré-floração) e 3 - estádio R7 (início da formação das vagens)]. A adubação nitrogenada via solo aumentou a matéria seca das plantas, o teor e acúmulo de N na parte aérea, o número de vagens por planta, a produtividade de grãos e o teor e produtividade de proteína na cultura do feijão comum. Independentemente da adubação nitrogenada via solo, o fornecimento de N via foliar aumentou a produtividade de grãos e proteína, sendo a ureia-formaldeído (Coron®) ligeiramente mais eficiente que a ureia comum. A aplicação de ureia-formaldeído aumentou a produção da matéria seca das plantas, o número de vagens por planta e a produtividade de grãos e proteína, independentemente do estádio em que foi realizada a pulverização nas folhas. As maiores produtividades de grãos foram obtidas com a aplicação de doses entre 3,1 e 5,0 kg ha-1 de N na forma de ureia-formaldeído. O tamanho dos grãos não foi afetado pela aplicação de N via foliar. / The use of slow or controlled release fertilizers is considered efficient for agriculture because it provide nutrients on a regular and continuous supply, according to the plant need. However, not exist wide information about the use of these sources in the common bean crop (Phaseolus vulgaris L.). Thus, this study aimed to evaluate the effect of the foliar application of nitrogen (N) sources at different plant development stages of the plant on grain yield and quality of common bean crop, grown in the presence and absence of the N application to the soil. For this, seven trials were conducted, i.e., two in field conditions (experiments I and II) and repeated on three growing conditions. The field trials were conducted in "rainy season" and "dry season" of agricultural year 2012/13, performed in randomized complete blocks. The experiment I was composed of 20 treatments, with the combination of four N doses (0, 45, 90, and 180 kg ha-1) and five treatments with foliar N application (1 - control - without application of N by leaf; 2 - 2.5 kg ha-1 N as urea (UC), 3 - 5.0 kg ha-1 N-UC, 4 - 2.5 kg ha-1 N as urea-formaldehyde (UF); 5 - 5.0 kg ha-1 N-UF). The experiment II was composed of 12 treatments, with four doses of urea-formaldehyde (0, 1.25, 2.5, and 5.0 kg ha-1) for foliar N supply and three times of application [1 - V4 (three fully expanded trifoliate leaves), 2 - R5 stage (pre-flowering) and 3 - R7 stage (initial pod development)]. Soil N fertilization increased the plant dry matter, content and accumulation of N in the shoot, the number of pods per plant, grain yield and content and protein yield in common bean crop. Regardless of N fertilizer in the soil, the supply of N foliar increased grain yield and protein, being that urea-formaldehyde (Coron®) was slightly more efficient than common urea. The application of urea-formaldehyde increased the production of dry matter yield, number of pods per plant and grain yield and protein, regardless of the stage in which it was carried out spraying the leaves. The highest grain yield was obtained with application rates between 3.1 and 5.0 kg ha-1 N as urea-formaldehyde. The grain size was not affected by foliar application of N. / CNPq: 140182/2012-8

The eye lens grows continuously throughout life and changes its shape as the eye changes focus from a distant to a near object (the process of accommodation). These changes are complex because they may affect not only the shape of the lens, but also its refractive index distribution. To date there has been no satisfactory technique for directly and non-invasively measuring these changes. In this study the refractive index distribution through the isolated lens was measured non-invasively using a novel MRI technique. The dependence of the refractive index value of lens tissue on its transverse relaxation rate (R2) was determined empirically from measurements on lens homogenate samples. Using a multi-spin-echo imaging sequence, data were acquired for constructing R2 maps of a central slice through the isolated lens. These R2 maps were transformed to refractive index maps using the empirically determined dependence of refractive index on R2. Using a standard algorithm for ray tracing through gradient index media, the propagation of light rays through the index map were simulated. The optical properties of the lens, such as focal length, were then measured. The technique was validated by also directly measuring the focal length of each lens using laser ray tracing. The subtle changes in refractive index distribution that are responsible for the dramatic change in the optical properties of the isolated lens with age, were observed for the first time. The decrease in surface power of the isolated lens with age accounted only partially for the decrease in total lens power with age, the remainder resulting from a reduction in the gradient of refractive index (GRIN) power. It is likely that this reduction in GFUN power is the mechanism by which the eye maintains emmetropia (good distant vision) with age despite the increasing curvature of its surfaces. The reduction in the GRIN power of the lens was found to be mainly due to a flattening of the refractive index profile in the central region of the lens, accompanied by steepening of the profile near the edge of the lens. In agreement with a previous MRI study of the isolated human eye lens, this study found a decrease in the refractive index of the nucleus with age. However the age related change in this study was not as large and not found to be statistically significant. The results demonstrate that existing simple models for the optics of the eye lens are inadequate to accurately describe its properties. Several more sophisticated models were considered in an attempt to describe better the age-dependent changes that occur in both the power of the lens and its longitudinal aberration. Mathematical modelling was also used to simulate the accommodative process and investigate possible changes in the index distribution of the lens that may occur with accommodation. A preliminary in vivo study was performed aimed at observing the change in the refractive index distribution of the eye lens with age and accommodation. These results demonstrated the feasibility of the technique for in vivo applications and showed that within experimental error there is little change in the central refractive index of the lens with age. However the resolution achievable with standard clinical imaging sequences and signal detection hardware was not optimal for in vivo refractive index mapping of changes in the human eye lens with accommodation. Finally therefore, methods for refining the technique for in vivo applications are discussed which may make it possible to directly and simultaneously measure both the shape and refractive index distribution of the lens with age and accommodation.

Le rendement en grains (Rdt) et la teneur en protéines (%Prot) sont deux cibles majeures dans les programmes de sélection variétale chez le blé car ces caractères contribuent à la valeur économique de cette culture. Malheureusement, leur amélioration simultanée est empêchée par la relation négative %Prot-Rdt. Il a été montré que l’écart à cette relation (“Grain Protein Deviation”, GPD) est déterminé en partie génétiquement et serait utile pour modifier cette relation négative mais ses bases biologiques restent mal comprises à ce jour. Nous avons montré que le GPD est principalement relié à la variabilité génétique pour l’absorption d’azote post-floraison (ABSN) dans les conditions agro-climatiques du Nord-Ouest de l’Europe. Nous proposons que la variabilité génétique pour l’accès à l’azote du sol (architecture et fonctionnement racinaire) ou pour la régulation de ABSN par le statut azoté (transport et assimilation de l’azote) pourrait expliquer le GPD. Etant donné que le retardement de la sénescence durant la période post-floraison peut résulter en une augmentation de ABSN, nous avons analysé les déterminants génétique des relations entre durée de sénescence des feuilles après floraison et Rdt ou %Prot, observées au niveau phénotypique, en utilisant des données acquises sur une population de cartographie de blé cultivée au sein d’un large réseau expérimental. Une association positive entre durée de sénescence des feuilles après floraison et %Prot ou Rdt a été observée selon les environnements étudiés. Nous faisons l’hypothèse que l’impact d’un retardement de la sénescence des feuilles après floraison pourrait être modulé selon la disponibilité en azote durant cette période, ce qui conduirait à modifier la relation %Prot-Rdt selon les environnements étudiés. Enfin, des données obtenues sur trois populations de cartographie cultivées dans un large réseau expérimental ont permis de suggérer, après méta-analyse de QTL, des régions génomiques potentiellement utiles en sélection pour améliorer la %Prot sans diminuer le Rdt. Ceci a permis de mettre en avant des régions situées sur les chromosomes 2A et 3B. En particulier, la région située sur le 2A pourrait être reliée à la présence d’un gène codant pour une glutamine synthétase chloroplastique qui a été associée à la variabilité génétique pour %Prot chez le blé tendre dans une étude antérieure. / Grain yield (GY) and grain protein concentration (GPC) are two major targets in wheat breeding programs as these traits contribute to the economic value of the wheat crop. Unfortunately, their simultaneous improvement is hampered by the genetic negative GPC-GY relationship. It has been shown that the deviation to this relationship (“Grain Protein Deviation”, GPD) has a genetic basis and might be useful to shift this negative relationship but its biological bases remain unclear. GPD was shown to be mainly related to the genetic variability for post-anthesis nitrogen (N) uptake (PANU) in the North-West European agro-climatic conditions. We proposed that the genetic variability for the access to N in the soil (root architecture and functioning) or for the regulation of PANU by the plant N status (N transport and assimilation) could explain GPD. As delaying leaf senescence during the post-anthesis period might result in increasing PANU, we analysed the genetic determinants of the phenotypic relationships between leaf senescence duration after anthesis and GPC or GY using data obtained on a wheat mapping population grown in a large mutli-environment trial network. A positive association was found between leaf senescence duration and GPC or GY depending onthe environment. We suggested that the impact of delaying leaf senescence after anthesis on GY or GPC might be modulated by the N availability during the post-anthesis period and would lead to modify the GPC-GY relationship depending on the considered environments. Finally, data obtained on three connected mapping populations grown in a large mutli-environment trial network were used to suggest by meta-QTL analysis potential genomic regions possibly useful in wheat breeding to improve GPC without reducing GY. This put forward genomic regions located on the 2A and 3B chromosomes as potentially interesting targets to improve GPC. In particular, the region on the 2A might be related to a chloroplastic glutamine synthetase gene previously shown to be associated with genetic variability for GPC in bread wheat.

La concentration en protéines des grains est un critère qualitatif majeur qui conditionne la valeur économique et technologique du blé tendre (Triticum aestivum L.). Cependant, la forte relation négative existant entre concentration en protéines et rendement en grains implique que l’amélioration de la concentration en protéines par une approche génétique soit complexe à atteindre sans impacter négativement le rendement. Pour contourner cette difficulté, il a été proposé qu’une sélection variétale basée sur l’écart à cette relation négative (nommé Grain Protein Deviation ; GPD) permette d’améliorer la concentration en protéines indépendamment du rendement. Au niveau physiologique, le GPD est fortement corrélé à la capacité des génotypes à absorber de l’azote après floraison indépendamment de la quantité d’azote déjà absorbée à floraison, suggérant que la satiété en azote soit à la base de son établissement. Envisager une sélection sur la base du GPD nécessite cependant d’acquérir des connaissances approfondies des mécanismes impliqués dans la régulation de l’absorption d’azote par la satiété en azote, qui permettraient de cibler précisément des traits simples à quantifier et robustement associés à cette capacité accrue d’accumulation de protéines dans les grains.Cette étude se base sur deux expérimentations conduites en conditions contrôlées et une expérimentation au champ. Dans chacune de ces expérimentations, différents niveaux de fertilisation ont été appliqués en pré-floraison afin d’obtenir des statuts azotés contrastés à floraison. L’effet du statut azoté à floraison sur l’absorption post-floraison a ensuite été observé dans différentes conditions de disponibilités d’azote après floraison. Des mesures physiologiques et moléculaires ont été réalisées en parallèle des mesures d’absorption d’azote.Nous avons mis en évidence que l’absorption d’azote post-floraison présente une dynamique élaborée qui suppose qu’elle est soumise à des régulations complexes. Parmi celles-ci, le statut azoté des plantes à floraison conditionne en grande part la quantité d’azote absorbée dans les jours qui suivent la floraison (PANUprécoce , de floraison à floraison + 250 degrés-jour). La quantité de PANUprécoce se présente comme un déterminant fort de la concentration en protéines des grains du fait de la forte corrélation positive observée entre ces deux traits en conditions contrôlées et au champ, et ce indépendamment du niveau de rendement. L’étude de deux génotypes robustement contrastés pour le GPD a montré qu’à statuts azotés équivalents, la quantité de PANUprécoce est sujette à des effets génétiques qui tendent à confirmer l’impact de la variabilité génétique de satiété en azote sur l’établissement du GPD.Ces travaux ont permis de proposer des marqueurs du GPD potentiellement valorisables en sélection. Au niveau physiologique, la croissance des tiges après floraison se présente comme un marqueur prometteur du GPD car ce trait est fortement corrélé à la PANUprécoce. Au niveau moléculaire, la concentration en nitrates des racines, également soumise à des effets génétiques, est proposée comme marqueur potentiel du fait de son rôle probable dans la régulation expressionnelle des gènes impliqués dans l’absorption et l’assimilation d’azote. / Grain protein concentration is one of the major qualitative criteria of bread wheat (Triticum aestivum L.) economic and technological value. However, the negative relationship existing between protein concentration and grain yield implies that grain protein concentration improvement is complex to achieve without detrimental effect on grain yield. Breeding programs based on the deviation to this negative relationship (Grain protein deviation of GPD) have been proposed to be a suitable strategy to improve grain nitrogen concentration without detrimental effects on yield. At a physiological level, GPD is strongly correlated with genotypes aptitude to uptake nitrogen after flowering independently of the nitrogen amount already taken up before this stage, suggesting that satiety for nitrogen could be involved in its establishment. Breeding for GPD implies however a more detailed knowledge of the processes implied in nitrogen uptake regulation by nitrogen plant satiety. This would allow targeting traits both simple to measure and robustly associated with this increased capacity to accumulate proteins in grains.The present study is based on two experiments carried on under controlled conditions and a third led under field conditions. In all experiments, various levels of pre-flowering fertilization were applied in order to obtain contrasted plant nitrogen status at flowering. Nitrogen status effect on post-flowering nitrogen uptake was observed under various post-flowering N availability conditions. Physiological and molecular measurements were carried out in parallel with uptake measurements.We highlighted that post-flowering nitrogen uptake has an elaborate dynamic, suggesting the involvement of complex regulations. Among these, plant nitrogen status at flowering determines to a great extent the amount of nitrogen taken up during the days following flowering (early PANU, from flowering to flowering +250 °C.days-1). Early PANU appears to be a strong determinant of grain protein concentration, as strong positive correlations were observed between these two traits both under controlled conditions and field conditions, independently of grain yield level. The study of two genotypes strongly contrasted for GPD highlighted that, despite comparable N status, early PANU is subjected to strong genetic variations which tend to identify N satiety as a determinant of GPD.The present study identified robust markers of GPD of potential use in plant breeding. At a physiological level, post flowering stem elongation appears to be a promising marker of GPD since this trait is strongly correlated with early PANU. At a molecular level, root nitrate concentration, a trait submitted to genetic variations, is also proposed as a marker of GPD because of its role in the expression regulation of the genes governing nitrogen uptake and assimilation.

While a decrease of wild felid population has led to disruption of conservation programme, recent studies have shown the importance of immune regulation for determining health outcomes and co-infection. Immunoglobulin G is important for detecting and evaluating responses to infectious diseases and vaccination. But, there is limited information on felid immunoglobulins and their role for functional immunity. This study aimed at isolating and characterizing lion’s immunoglobulin G. Lions’ sera (n = 68) were processed using the MagReSyn® magnetic beads and the final protein concentration was determined using the Xpose™ Trinean Spectrophotometer. The cross-reactivity of goat anti-cat immunoglobulin with sera of lions and other species was analysed using ELISA. High cross-reactivity was observed in lions ranging from 87.7 to 100%, and low reactivity with rhino (22.4%) followed by chicken (0.01%). The protein concentration from purified sera yielded 39.09 mg/ml. Molecular weight of lion IgG 150-160 kDa was detected with both chains at 54-56 kDa and 24-26 kDa on SDS PAGE. These results indicate a potential aid in developing serological tools to monitor exposure to micro-organisms of lions. / Agriculture and  Animal Health / M. Sc. (Agriculture)

Integrated aquaponic food production systems are capable of producing more food on less land using less water than conventional food systems, and marine systems offer the potential of conserving freshwater resources. However, critical factors such as suitable species combinations, environmental conditions (salinity and pH), and nutrient management (animal to plant ratio, C/N ratio, and dietary crude protein) have not been fully understood for marine systems. There were four objectives in this project. The first objective was to evaluate the growth performance of potential comparable combination (whiteleg shrimp with three halophytic plants) for the development of marine aquaponics with BFT under different salinities. The second objective was to evaluate stocking densities and the C/N ratio on growth and production of whiteleg shrimp and three halophytes. The third objective was evaluation of varying concentrations of dietary crude protein in practical diets fed to shrimp raised in biofloc aquaponic saltwater systems. The fourth objective was to evaluate effects of pH levels and additional C on the growth and production of whiteleg shrimp and five plant species in marine aquaponics. Four conclusions were determined: 1) Regarding marine aquaponics, whiteleg shrimp and the three halophytes (Atriplex hortensis, Salsola komarovii, and Plantago coronopus) are suitable combinations for future development. According to the research results, shrimp performed better in a salinity of 15 and 20 ppt; yet, plants performed better in a salinity of 10 and 15 ppt. Therefore, a salinity of 15 ppt is suggested as the optimal saline condition for shrimp and the three halophytes in an indoor marine aquaponics system. In addition, inoculating probiotics do have the efficiency of stabilizing water quality, cultivating microbial community, and enhancing the health of shrimp and plants in the operation of aquaponics. 2) The stocking density ratio and C/N ratio exerted significant impacts on the performance of shrimp and plants in marine aquaponics. Shrimp performed better with the stocking density of 2:1 and 3:1, with no impact from the C/N ratio. Conversely, plants performed better with the stocking density of 3:1 and 5:1 with the C/N ratio at 15. Therefore, a stocking density ratio of 3:1 with a C/N ratio at 15 is suggested as the optimal condition for shrimp and the three halophytes in an indoor marine aquaponic food production system. Inoculating the water with biofloc and applying probiotics regularly can enhance the management of water quality and the health of shrimp and plants in aquaponics. 3) Among the findings of the study, shrimp growth was not affected by the protein content of the feed, suggesting that it is possible to use feeds with lower protein concentration when culturing shrimp in biofloc-based marine aquaponics. However, plants grew better in the treatments with higher protein content feed in the early and middle stages of production. Hence, for maximum production, providing a higher protein concentration feed (35 %) in the early stages of system start-up, and switching to a lower protein concentration feed (30 %) in the later stages of cultivation might be feasible. 4) The current study found no significant effects of pH or additional C on shrimp performance. In contrast, plants grew better in lower pH treatments, while additional C supplements improved the performance of plants grown in higher pH treatments and had similar results to the lower pH treatments. We suggest that RO water is not suitable source of water for shrimp-based marine aquaponics if ionic composition is not managed. The addition of C, however, led to improved growth and yields of most plants. Hence, adding C can be a promising approach in marine aquaponics to enhance the resistance to the abiotic stress of plants and improve their growth.<div> <br>The present study on marine aquaponics has produced important findings that will fill some knowledge gaps, provide management guidelines for production, and facilitate its development. <br></div>