Tesi sul tema "Plantes en architecture"
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Barthélémy, Daniel. "Architecture et sexualité chez quelques plantes tropicales : le concept de floraison automatique". Montpellier 2, 1988. http://www.theses.fr/1988MON20192.
Testo completoLemoine, Damien. "Fonctionnement hydrique du hêtre : architecture hydraulique et sensibilité à la cavitation". Nancy 1, 2000. http://docnum.univ-lorraine.fr/public/SCD_T_2000_0013_LEMOINE.pdf.
Testo completoLauri, Pierre-Eric. "Architecture de l'arbre fruitier - de la morphologie des plantes à l'agronomie". Habilitation à diriger des recherches, Université Montpellier II - Sciences et Techniques du Languedoc, 2007. http://tel.archives-ouvertes.fr/tel-00377121.
Testo completoBarthélémy, Daniel. "Architecture et sexualité chez quelques plantes tropicales le concept de floraison automatique /". Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376116145.
Testo completoStephan, Jean. "Architecture 3D et microclimat lumineux de l'arbre". Phd thesis, Clermont-Ferrand 2, 2007. http://www.theses.fr/2007CLF21754.
Testo completoMorin, Nathalie. "Les Microcodium : architecture, structure et composition, comparaison avec les racines calcifiées". Montpellier 2, 1993. http://www.theses.fr/1993MON20025.
Testo completoCremers, Georges. "Architecture végétative et structure inflorescentielle de quelques melastomaceae guyanaises /". Paris : ORSTOM, 1986. http://catalogue.bnf.fr/ark:/12148/cb34908935j.
Testo completoPreuksakarn, Chakkrit. "Reconstructing plant architecture from 3D laser scanner data". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20116/document.
Testo completoIn the last decade, very realistic rendering of plant architectures have been produced in computer graphics applications. However, in the context of biology and agronomy, acquisition of accurate models of real plants is still a tedious task and a major bottleneck for the construction of quantitative models of plant development. Recently, 3D laser scanners made it possible to acquire 3D images on which each pixel has an associate depth corresponding to the distance between the scanner and the pinpointed surface of the object. Standard geometrical reconstructions fail on plants structures as they usually contain a complex set of discontinuous or branching surfaces distributed in space with varying orientations. In this thesis, we present a method for reconstructing virtual models of plants from laser scanning of real-world vegetation. Measuring plants with laser scanners produces data with different levels of precision. Points set are usually dense on the surface of the main branches, but only sparsely cover thin branches. The core of our method is to iteratively create the skeletal structure of the plant according to local density of point set. This is achieved thanks to a method that locally adapts to the levels of precision of the data by combining a contraction phase and a local point tracking algorithm. In addition, we present a quantitative evaluation procedure to compare our reconstructions against expertised structures of real plants. For this, we first explore the use of an edit distance between tree graphs. Alternatively, we formalize the comparison as an assignment problem to find the best matching between the two structures and quantify their differences
Charpentier, Anne. "Biologie des populations d'une espèce clonale : architecture et fonctionnement clonal chez "Scirpus maritimus" dans les marais temporaires méditerranéens du sud de la France". Montpellier 2, 1998. http://www.theses.fr/1998MON20040.
Testo completoLouarn, Gaëtan. "Analyse et modélisation de l'organogenèse et de l'architecture du rameau de vigne (Vitis vinifera L. )". Montpellier, ENSA, 2005. http://www.theses.fr/2005ENSA0024.
Testo completoIn viticulture, plant canopy structure plays a key role in detennining yield and quality. Highly variable from one pair Genotype x Training Systeme (G x TS) to another, it results from complex interactions between vegetative growth of the shoots, bearing properties of the genotype and farming practices of the wine-grower. In order to model vine canopy structure development in response to environmental factors (temperature, light, water supply) this study focused on two key points : (i) the analysis and modelling of shoot organogenesis for irrigated / fertilized vines (Cv. Grenache N. Am Syrah) and (ii) the analysis and modelling of spatial distribution of leaf area for a wide range of G x TS pairs. The first part of the study relied on several experiments carried out in pots where vines were thinned to one vertically trellised shoot per pot, irrigated daily and fertilized monthly. As a first step, standard organogenesis of the primary and secondary axis of the shoot were characterised on shoots whose bunches were removed as soon as they appeared. As a second step, the effects of fruit load and hedging on organogenesis of primary and secondary axis were quantified relatively to the standard. Our results show that primary axis development is not significantly different between genotypes and is not reduced when ftuit are not removed. On the other hand, secondary axis development is significantly different between genotypes. Concomitant differenees in distribution of secondary leaf area along the primary axis have been linked to differences in rate of leaf emergence on the secondary axis. Furthermore, we show that hedging strongly reduces the total amount of leaf produced at the shoot scale but didn't significantly affect total leaf area. Finally, it was also shown for the range of fruit load studied that keeping fruits reduces organogenesis of secondary axis but not organogenesis of primary axis. Branches doser to the bunches were more affected. Biological origin and agronomical repercussions of observed phenomena are discussed. The second part of the study dealt with the description and validation of a stochastic reconstruction model enabling dynamic modelling of contrasted vine canopy structures. This model considers canopy as the aggregation of "clouds of leaves" described at the shoot scale. The shape of the external envelope of the sooot depends on a simplified set of parameters. For this study, the number and mean surface area of leaves were model inputs. Model parameterisation was undertaken in experimental vineyards for eight G x TS pairs. Validation was successfully carried out on a sample of four contrasted G x TS pairs. Possibilities for connection of this reconstruction model with a dynamic model of shoot growth are discussed as are the agronomical applications of such a tool
Garcia-Villanueva, Eduardo. "Développement conjoint des systèmes aérien et racinaire chez deux génotypes de pommier (Malus X domestica Borkh)". École nationale supérieure agronomique (Montpellier), 2004. http://www.theses.fr/2004ENSA0020.
Testo completoChenu, Karine. "Variabilité phénotypique de l'architecture de la rosette d'Arabidopsis thaliana en réponse au rayonnement : analyse et modélisation de la réponde de différents génotypes". Montpellier, ENSA, 2004. http://www.theses.fr/2004ENSA0014.
Testo completoPlant development is highly plastic in response to light conditions. In this study, we have investigated how plant architecture is modified by a reduction in incident light in Arabidopsis thaliana. Here we have compared how organogenesis and morphogenesis responses to incident light vary among genotypes and proposed a functionnal-structural model of leaf development that responds to temperature and light. Plants of eight genotypes were grown in a growth chamber under various levels of incident light, characterized in term of spectral and directional components. The amount of light absorbed by the plants was estimated using 3D virtual plants and a radiative balance model. A reduction in incident light decreased leaf area and changed petiole and leaf morphology, without affecting the phyllotaxy and the leaf number. The leaf area reduction resulted from antagonist effects on leaf development processes, namely a decrease in the phytomer initiation rate and in the initial leaf expansion rate, and an increase in the duration of leaf expansion. The two former variables were quantitatively related to the amount of light absorbed by the plant whereas the latter to the light intensity. These relationships were used to compare the genotype responses to incident light. A broad range of responses was observed among genotypes for leaf initiation rate and the duration of leaf expansion. In contrast, the initial expansion rate varied among genotypes but its response to light was stable. The analysis framework established was also used to build a model of simulation that estimates leaf expansion at given temperature and irradiance. To conclude, plants respond in an integrated manner to reduced incident light in such a way to optimise light interception. The relationships identified are proposed as a possible way to analyse phenotypic plasticity of various genotypes of Arabidopsis
Letort, Véronique Quitterie. "Adapatation du modèle de croissance GreenLab aux plantes à architecture complexe et analyse multi-échelle des relations source-puits pour l'identification paramétrique". Châtenay-Malabry, Ecole centrale de Paris, 2008. http://www.theses.fr/2008ECAP1083.
Testo completoPlant growth modelling can be considered at different temporal and spatial scales. In the growth model GreenLab, spatial units are phytomers and temporal steps are growth cycles. Such scales are relevant for most crops but regarding branching plants with complex structures, description at these scales is difficult to achieve. The thesis proposes a multi-scale analysis of GreenLab according to different levels of simplification for parameter identification. We first identified the process influenced by plant architecture (e. G. Cambial growth). Two kinds of approaches were discussed to address the problem: (i) development of simplified models with different levels of variable aggregation and (ii) parameter identification for the complete model using simplified targets. We introduced three levels of model simplification according to the feasibility of the associated experimental protocols and to the classical set of data usually collected for forestry models. For each of these three levels, we theoretically studied the conservation of some key-variables of the model from one simplification level to another one. On this basis, we proposed simplified equations based on aggregate variables and consistent with the GreenLab approach. We developed methods to identify not only functional but also topological parameters of plants, depending on the version of the model (deterministic, stochastic or mechanistic) and depending on the nature of available data. The applications presented in this thesis mainly concern trees but also other kinds of branched plants
Taugourdeau, Olivier. "Le sapin pectiné (Abies alba Mill., PINACEAE) en contexte méditerranéen : développement architectural et plasticité phénotypique". Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20196/document.
Testo completoThe aim of this work is to assess silver fir phenotypic plasticity with an architectural approach. This work take place in the context of understanding perennial plant development linked with their environment and the context of climate change in the Mediterranean region.For this, ex-situ (shading and watering treatments) and in-situ (shading and elevation gradients) studies were performed. They consist of the study of architectural traits variability, mainly measured at annual shoot scale, linked with plant architecture and environment.The results are the quantification of silver firs development up to reproductive tree and the quantification of plastic responses to light and hydric environment and climate. The concept of architectural plasticity and it consequences was also discussed
Barczi, Jean-François. "Une Contribution Logicielle dédiée la simulation de l'architecture et de la croissance des plantes". Phd thesis, Ecole Centrale Paris, 2008. http://tel.archives-ouvertes.fr/tel-00520900.
Testo completoRoman, Hanaé. "Etude du photocontrôle du débourrement : Rôles des photorécepteurs (phyA, phyB, cry1) et des cytokinines dans la transduction du signal lumineux". Thesis, Angers, 2015. http://www.theses.fr/2015ANGE0081.
Testo completoThrough photosynthesis and photomorphogenesis, light highly controls plant branching. Roses (Rosa hybrida L.) exhibit for example a strong inhibition of bud outgrowth under darkness. Better understanding the action of light in branching will give new opportunities to horticulturists. Yet, little is known about the light signalling pathway during bud outgrowth. In particular, the involvements of each photoreceptor and of cytokinins (CK), plant hormones acting as promoters of bud outgrowth, in the transduction of the light signal during bud outgrowth have not been assessed. In this work, exogenous applications and quantification of CK under darkness show that the photocontrol of bud outgrowth goes through the photo-regulation of CK. Light controls CK neo-synthesis and transport from the internode toward the bud, and inhibits their degradation. The neo-synthesised CK initiate bud outgrowth by regulating a set of major genes involved in bud outgrowth (strigolactones signalling, metabolisms and transports of auxin and of sugar, cell division and expansion). In order to identify the photoreceptors that are involved in this process, we studied pea (Pisum sativum L.) mutants. Our research indicate that the bud outgrowth profile along the stem is under photocontrol: being basitonic under white light, this profile becomes acrotonic under darkness or after mutations of phyA, phyB and cry1. These three photoreceptors thus play a major role in the control of the correlative inhibitions between buds. Since applications of CK allowed to restore the wild-type basitonic profile in the phyB mutant, this suggests that the light signalling pathway towards CK involves phyB
De, Pessemier Jerome. "Contribution to the study of genetic determinism involved in the root response to nitrate". Doctoral thesis, Universite Libre de Bruxelles, 2015. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/220298.
Testo completoDoctorat en Sciences
info:eu-repo/semantics/nonPublished
Pradal, Christophe. "Architecture de dataflow pour des systèmes modulaires et génériques de simulation de plante". Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTS034.
Testo completoBiological modeling, particularly of plant growth and functioning, is a rapidly expanding field that is useful in addressing climate change and food security issues at the global level. Modeling and simulation are essential tools for understanding the complex relationships between plant architecture and the processes that influence their growth in a changing environment.For plant modeling, a large number of formalisms have been developed in many disciplines and at different scales of representation.The objective of this thesis is to define a modular architecture that allows to simulate structural-functional plant systems by reusing and assembling different existing models.We will first study the different approaches to software reuse proposed by Krueger, then blackboard systems, and scientific workflow systems.These different approaches are used to cooperate, reuse and assemble software artifacts in a modular manner.Based on the observation that these systems provide the abstractions necessary for the integration of various artifacts, our working hypothesis is that a hybrid architecture, based on blackboard systems with dataflow-driven procedural control, would both achieve modularity while allowing the modeler to maintain control over execution.In Chapter 2, we describe the OpenAlea platform, a platform with software components and a scientific workflow system, allowing the assembly and composition of models through a visual programming interface. In Chapter 3, we propose a data structure for the blackboard, combining a topological representation of plant architecture at different scales, the Multiscale Tree Graph, and its geometric spatialization using the 3D PlantGL library. In chapter 4, we present the lambda-dataflows, an extension of dataflows allowing to couple simulation and analysis.Then, in Chapter 5, we present a first application, which illustrates the use of a generic gramineous leaf model in different plant models. Finally, in Chapter 6, we present all the architectural elements used to develop a generic framework for modelling the development of foliar diseases in an architectural canopy.The architecture presented in this thesis and its implementation in OpenAlea are a first step towards the realization of open integrative modeling platforms, allowing the cooperation of heterogeneous models in biology. The use of scientific workflow formalism in analysis and simulation makes it possible to consider in the short term the development of collaborative and distributed simulation platforms on a large scale
Bruy, David. "Diversity, ecology and evolution of monocaulous plants in New Caledonia". Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTG087/document.
Testo completoThe convergent evolution in growth habit is a fundamental phenomenon linking plant ecology and evolution. Remarkably illustrated in island biotas, this phenomenon has never been identified in the original and megadiverse New Caledonian biodiversity hotspot. Through an approach combining plant architecture, functional traits, taxonomy, phylogeny and environmental data, this thesis analyses the evolutionary history of the scarcely known monocaulous growth habit in New Caledonia. Monocauls are self-supporting woody plants whose cardinal functions rely on a single visible stem. In New Caledonia, they are represented by 182 dicotyledonous species belonging to 41 genera and 30 families and are critically endangered. The repeated evolution of the monocaulie in New Caledonia, resulting from at least 31 independent events, is one of the most remarkable cases of convergence in insular environments. In the genus Atractocarpus (Rubiaceae), monocauly evolved recently two to three times through branch reductions into inflorescences, emphasizing the importance of heterochronic processes in the evolution of growth habit. Monocauly is strongly correlated with several traits illustrating major constraints in functional coordination. The evolution of monocauly is strongly associated with rainforests and ultramafic substrate, and seems to have contributed to the diversification of lineages by niche partitioning. The remarkable convergence toward monocauly in New Caledonia can be explained by four major hypotheses: (i) the structural features of rainforests (related to cyclone frequency and intensity) favoring unidirectional exploration of space, (ii) the edaphic constraints associated with ultramafic substrate favoring architectural pauperization, (iii) the historical absence of large native browsers to which monocauls are particularly sensitive, and (iv) the persistence of rainforest during – and spread-out after – glacial episodes that served as refugia and further provided ecological opportunities
Letort, Veronique. "Adaptation du modèle de croissance GreenLab aux plantes à architecture complexe et analyse multi-échelle des relations source-puits pour l'identification paramétrique". Phd thesis, Ecole Centrale Paris, 2008. http://tel.archives-ouvertes.fr/tel-00365172.
Testo completoNous avons tout d'abord identifié les conditions sous lesquelles, dans la formulation actuelle du modèle, la production photosynthétique et l'allocation de biomasse dans la plante sont indépendantes de son architecture. Nous avons établi qu'en revanche cette interaction est forte pour certains processus comme la croissance radiale. Deux types de démarches ont été abordées pour répondre au problème soulevé: (1) le développement de modèles simplifiés, avec différents niveaux d'agrégation des variables et (2) l'ajustement du modèle complet sur des cibles simplifiées. Nous avons envisagé trois niveaux de simplification du modèle selon des critères basés sur les applications visées, la faisabilité du protocole expérimental associé et le type de données classiquement collectées pour les modèles forestiers. Pour chacun de ces trois niveaux, nous avons mené une étude théorique pour relier les paramètres du modèle complet à ceux des différents modèles simplifiés de manière à avoir conservation de certaines variables-clés du modèle (notamment le rapport de la production de biomasse sur la demande de la plante). Sur cette base, nous proposons des équations simplifiées régissant le comportement de la plante à l'aide de variables agrégées.
En pratique, nous avons cependant souvent accès à certaines informations sur l'architecture de la plante, même si elles ne sont pas du niveau de détail des données issues de la simulation : ces informations peuvent provenir d'échantillonnages ou bien d'analyses botaniques préliminaires. En conséquence, nous avons étudié les méthodes permettant l'ajustement non seulement des paramètres fonctionnels de la plante mais également des paramètres contrôlant son développement topologique. Différentes méthodes sont proposées selon la version du modèle (déterministe, stochastique ou déterministe avec rétro-action de l'état trophique de la plante sur son développement) et selon la nature des données disponibles. Les applications de la thèse concernent principalement les arbres mais se sont également diversifiées à plusieurs types de plantes branchées.
Massonnet, Catherine. "Variabilité architecturale et fonctionnelle du système aérien chez le pommier (Malus domestica Borkh. ) : comparaison de quatre cultivars par une approche de modélisation structure-fonction". Montpellier, ENSA, 2004. http://www.theses.fr/2004ENSA0018.
Testo completoBeyond the well-described architectural diversity between apple tree cultivars, a functional variability is suspected, still scarcely investigated, which could affect their productivity and adaptation potential. Ln other respects, it has been assurned that functional variability of different apple cultivars considered at an integrated scale could depend on the architectural organization of the aerial system and on the variability of foliage functions. The comparison which was here carried out between genotypes inc1uded 4 apple cultivars: Fuji and Braeburn, on the one hand, and Ariane and X3305, on the other hand. The trees were respectively 7-years-old and 2-years-old at the beginning of this study. Trees were cultivated in an experimental orchard which was irrigated and submitted to standard professional praètice. Between-trees study of the architectural variability revealed different dynamics of foliage setting between younger and older trees. Sorne differences in shoot composition were also revealed between trees of the same age, resulting in different light interception efficiency which was quantified by the STAR parameter (Silhouette to Totalleaf Area Ratio). A method for tree 3D-structure description was validated, which used a mixed approach of foliage digitalization and reconstruction. Functional comparison at the leaf scale showed that parameters of stomatal regulation (Jarvis model) differed between the 4 genotypes, while photosynthetic parameters (biochemical model of Farquhar) showed little variation. Architectural and functional characteristics of each cultivar were taken into account to parameterize and apply the RATP functional-structural model, and their coupling made it possible to simulate light interception capacity, transpiration and carbon gain at the branch scale. A sensitivity analysis of the model was applied to the Braeburn cultivar; it showed that architectural traits predominate when functional variability is considered at the branch scale. The research prospects opened by this ecophysiological approach applied to the apple tree by means of a functional-structural model are discussed
Gaillard, Anne-Laure. "Identification de motifs au sein des structures biologiques arborescentes". Phd thesis, Université Sciences et Technologies - Bordeaux I, 2011. http://tel.archives-ouvertes.fr/tel-00652227.
Testo completoBonnet, Pierre. "Intérêt de caractères négligés et exploration de nouvelles méthodes pour l'identification taxonomique : une application aux Orchidaceae Juss. du Laos". Montpellier 2, 2008. http://www.theses.fr/2008MON20203.
Testo completoAbichou, Mariem. "Modélisation de l’architecture 4D du blé : identification des patterns dans la morphologie, la sénescence et le positionnement spatial des organes dans une large gamme de situations de croissance". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLA022/document.
Testo completoThe simulation of plant architecture has become a very active front of research because of its importance for understanding the functioning of plants and their interactions with the environment. When analysing observations of experimental treatments, it is of a great interest to be able to simulate the architecture of the crop with sufficient fidelity to represent the specific traits resulting from the experiment. In this context, the objective of the thesis project was to develop an operational model allowing to simulate the 4D architecture of a collection of individual plants for the whole crop cycle and in a way faithful to the observations. Our approach builds on the experimental characterization of a range of commercial cultivars cultivated in the Paris region. These data represent a wide range of climatic sequences, sowing dates, densities of seedlings and nitrogen fertilization. The data analysis allowed us to identify stable and robust functions that describe the dynamics of appearance and mortality and the final dimensions of the different components of the plant. Our work brings also novel information on the evolution of their geometry and spatial organisation over time. These functions were coded into a model that describes the dynamics of the architecture of a collection of plants from their emergence to their full maturity. Our reconstruction method allowed us to generate 4D reconstructions for a large part of our experimental treatments; it has also been used in several projects carried out in parallel with this work. Our model can also be used to explore potential architectures traits in order to propose new ideotypes. Finally, our modelling approach can be applied to other cereals: it provides a framework for comparing patterns of morphology and development between species and provides a tool to study, by simulation, the impact of the architectural traits of each species
Da, Silva David. "Caractérisation de la nature multi-échelles des plantes par des outils de géométrie fractale : application à la modélisation de l'interception de la lumière". Montpellier 2, 2008. http://www.theses.fr/2008MON20158.
Testo completoWith concerns such as sustainable development or climat changes, controling and understanding plant growth has become important society matters. Computer models that uses plant architecture, called "functional-structural plant models" (FSPMs), have become more and more widespread. Contrariwise to agronomic models based on the relations between few parameters, FSPMs allow to assess the relation between the three-dimensional structure of plants and the physical and ecophysiological processes that drive their development. However, plant architecture, and particularly its geometry, is rather complex and can be described at different detail levels. In this thesis we wanted to characterize the complex multiscale geometry of plants with few descriptors in order to be able to acknowledge the structure in simple models of light interception. First, we developped mathematical methods to characterize the multiscale geometry of plants using descriptors from fractal geometry. The fractal dimension allows one to characterize the way plants physically penetrate space as a function of the observation scale. To characterize the plant geometry more thoroughly, the fractal dimension needs to be complemented with a description of spatial density of geometric details at each scale: the lacunarity. We recall the usual definitions for both the fractal dimension and the lacunarity, analyze their limits, and propose variants of these descriptors that better suit the characterization of plant organization. These different definitions are then appraised on data bases of virtual and real plants. Second, we create a light interception model based on the plant multiscale organization. This model computes light interception at each scale, and allows to analyze the scale by scale relation between plant structure and its light interception ability. This model is then used and evaluated on isolated trees and heterogeneous canopies
Persello, Séverine. "Réponse du manguier, Mangifera indica L., à la taille : caractérisation et intégration dans un modèle structure-fonction des effets de la taille sur la croissance végétative et la reproduction". Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTG078/document.
Testo completoPruning is a common practice in tree fruit crops. However, its effects on the yield are variable and hardly predictable. In this thesis, we propose to study the effects of pruning on vegetative growth and reproduction for the mango tree (Mangifera indica L.), at the axis and at the tree scales, in order to better understand how fruit yield built-up following pruning. Pruning was characterized by two factors: pruning intensity, defined at the tree scale as the amount of fresh biomass removed per unit volume of canopy, and pruning severity, defined at the axis scale as the depth of pruning along the axis. At the axis scale, pruning intensity and severity had an effect on the occurrence, intensity and dynamics of vegetative growth. We also highlighted a major role of the diameter of the pruned axis on the occurrence and intensity of vegetative growth. The vegetative growth which results from pruning led to the emergence of new populations of axes whose proportions depend on pruning intensity. Flowering of these different populations of axes differ in terms of occurrence, intensity and dynamics and was affected negatively by pruning intensity and severity. At the tree scale, yields tended to be lower on moderately and intensively pruned trees as a result of a decrease of flowering rate and/or average weight of fruits. Lightly pruned trees had similar yields compared to unpruned trees. The effects of pruning on the vegetative growth, at the structural and temporal levels, were integrated in a functional-structural model of fruit yield and quality build-up. The model has shown that the number of axes and the leaf area removed at the pruning time were widely compensated by the vegetative growth stimulation that followed. The integration of the effects of pruning on reproduction will allow developing crop management techniques integrating pruning techniques in order to respond to agronomic issues related to mango tree as asynchronisms and irregular bearing
Capelli, Mathilde. "Décrypter l’irrégularité de production des fruitiers tropicaux via l’analyse des coûts de la reproduction : le cas du manguier (Mangifera indica L.)". Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT079/document.
Testo completoThe mango tree (Mangifera indica), the fifth fruit crop production in the world, is characterized by an irregular bearing pattern. Irregular bearing is responsible for economic difficulties for producers and for all actors along the fruit industry chain. A better understanding of mechanisms which trigger and maintain irregular bearing is therefore necessary. The first objective of this study is to provide a new perspective on irregular bearing of the mango tree using a concept developed in ecology and evolutionary biology, the costs of reproduction. The experiment was carried out dynamically at several spatial scales, growth unit (GU), scaffold branch, tree, and on four cultivars. Results show a negative effect, or cost, of reproduction on vegetative growth during the following cycle, with cultivar-specific behaviors related to their bearing pattern. In particular, an important reproductive effort reduces the probability of vegetative burst of the bearing GUs. The second objective is to study, for two cultivars and at the GU scale, the anatomical changes of the bearing axis during fruit growth, and hormonal and trophic mechanisms involved in the negative effects of reproduction on vegetative bud outgrowth. Results show that reproduction leads to cambium differentiation mainly in phloem, favoring nutrients and water supply to the fruit. Inflorescences and growing fruits release auxin, contributing to vegetative bud burst inhibition on fruiting GUs. Growing fruits mobilize starch reserves of bearing GUs. Their low starch content at and after harvest contributes to decrease their probability of vegetative burst, and/or delay it when it occurs. The results reveal a strong cultivar effect, and the involvement of these mechanisms in irregular bearing is discussed. Our results allow to better understand the factors maintaining irregular or alternate bearing of different mango cultivars. From a practical perspective, they suggest that pruning techniques adapted to each cultivar and GU fate may contribute to more regular production each year
Andrianasolo, Domohina Noromalala. "Génétique des populations et modèles d'architecture et de production végétale : application à la préservation des ressources génétiques des Mascarocoffea". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20225.
Testo completoMascarocoffea species (61 / 124 described, endemics to Madagascar) are highly endangered because of the considerable Madagascar area forest reduction. For their preservation, assessment of the Mascarocoffea diversity level in the FOFIFA Kianjavato Collection Research Station compared to four in situ populations was made. The collection population's diversity level is larger than that in situ, observed heterozygosity is similar with a significant allelic richness. Modeling the young individuals in these populations' growth and development by the GreenLab model helped to understand the development of the plant structure in accordance with the interspecific architectural variability in studied populations at different development stages. A good fitting on growth was obtained on the populations studied in the experimental plot. The evolution of the GreenLab model key variable, the source-sink ratio (Q / D), showed that the production of many more organs influences the ratio Q / D evolution in time. This variable affects organ size and Mascarocoffea architecture. An essay on adult individuals growing in different environments (in and ex situ), whose morphological, genetic and architectural parameters were determined in this study, would allow the plants response in terms of architecture depending on the environment in which they grow and to optimize the model. The detection of hybrid individuals in both in situ and at the collection would detect hybrids characters on the plant structure and consider integrating genetic parameters in the model
Barillot, Romain. "Modélisation du partage de la lumière dans l'association de cultures blé - pois (Triticum aestivum L. - Pisum sativum L.). Une approche de type plante virtuelle". Phd thesis, Université d'Angers, 2012. http://tel.archives-ouvertes.fr/tel-00854575.
Testo completoBenot, Marie-Lise. "Importance des traits clonaux dans la réponse à la défoliation et au pâturage chez des plantes herbacées". Phd thesis, Université Rennes 1, 2010. http://tel.archives-ouvertes.fr/tel-00473549.
Testo completoFeng, Lu. "Connexion entre modèles dynamiques de communautés végétales et modèles architecture-fonction – cas du modèle GreenLab". Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20190/document.
Testo completoPlant architecture implies the development of both topological and geometrical structure over time, which determines resource acquisition, in the meantime interacts with physiological processes. However it has long been overlooked in traditional community dynamics models. Based on plant architecture, functional-structural plant models (FSPM) have showed their particular capability in addressing questions like interactions between plant and environment (e.g. light interception), between structure development and growth (e.g. carbon allocation), as they take into account morphogenesis with organ-level explicit descriptions. Anyway, high demand of time and memory for simulation and inverse calculation prevents FSPM from further agricultural or sylvicultural practice. This thesis attempts the combination of a mathematic FSPM GreenLab and a crop model or an empirical forest model (EFM) to introduce individual-based architectural support for community growth study. In the case of maize, disagreement from stand level (by crop model PILOTE) and individual level (by GreenLab) growth simulations implies different emergence time of individuals, which is used to quantify the distribution. By supposing that theoretical projective area (Sp) is determined by the growth situation and the final size of individual architecture, the variance of Sp is reversely computed with the variance of organ compartment measurements to characterize individual variability. In the case of Black pine, architecture dynamics built in GreenLab according to Rauh's model (architecture model for pine tree) are adapted to the simulation of an EFM PNN. As a consequence, thinning scenarios are well incorporated in the final stand visualization. From these preliminary applications, following conclusions can be drawn: (i) FSPM is able to provide individual performances (i.e. organ development and expansion) inside an area of crop field for crop models. (ii) The crop model may regulate the combined form of individuals from integral level. Both aspects are significant to deepen understanding of stand growth. (iii) Architecture conceptions integrated in FSPM may be adapted to EFM simulations for a data-driven visualization. (iv) EFM can guarantee ecological/sylvicultural function for 3D stand visualization. To take into consideration biomass processes, additional observations are needed. As models are independent in combinations, the same methods can be extended to linkage with other stand models
Perez, Raphaël. "Analyzing and modelling the genetic variability of aerial architecture and light interception of oil palm (Elaeis guineensis Jacq)". Thesis, Montpellier, SupAgro, 2017. http://www.theses.fr/2017NSAM0001/document.
Testo completoIn this study we proposed to investigate the influence of oil palm architecture on the capacity of the plant to intercept light, by using 3D reconstructions and model-assisted evaluation of radiation-use efficiency. The first objective of this study was to analyse and model oil palm architecture and light interception taking into account genetic variability. A second objective was to explore the potential improvements in light capture and carbon assimilation by manipulating oil palm leaf traits and propose architectural ideotypes.Allometric relationships were applied to model these traits according to ontogenetic gradients and leaf position within the crown. The methodology allowed reconstructing virtual oil palms at different stages over plant development. Additionally, the allometric-based approach was coupled to mixed-effect models in order to integrate inter and intra progeny variability through progeny-specific parameters. The model thus allowed simulating the specificity of plant architecture for a given progeny while including observed inter-individual variability. The architectural model, parameterized for the different progenies, was then implemented in AMAPstudio to generate 3D mock-ups and estimate light interception efficiency, from individual to stand scales.Significant differences in leaf geometry (petiole length, density of leaflets and rachis curvature) and leaflets morphology (gradients of leaflets length and width) were detected between and within progenies, and were accurately simulated by the modelling approach. Besides, light interception estimated from the validated 3D mock-ups showed significant variations among the five progenies.Sensitivity analyses were then performed on a subset of architectural parameters to identify the architectural traits impacting on light interception efficiency and potential carbon assimilation over plant development. The most sensitive parameters over plant development were those related to leaf area (rachis length, number of leaflets, leaflets morphology), but fine attribute related to leaf geometry showed increasing influence when canopy got closed. In adult stand, optimized carbon assimilation was estimated on plants presenting a leaf area index (LAI) between 3.2 and 5.5 m2.m−2, with erected leaves, short rachis and petiole and high number of leaflet on rachis. Four architectural ideotypes for carbon assimilation were proposed based on specific combinations of organs geometry, limiting mutual shading and optimizing light distribution within plant crown.In conclusion, this study highlighted how a functional-structural plant model (FSPM) can be used to virtually explore plant biology. In our case of study, the 3D model of oil palm, in its conception and its application, permitted to detect the architectural traits genetically determined and influencing light interception. The limited number of traits revealed in the sensitivity analysis and the combination of traits proposed through ideotypes could guide further breeding programs. Forthcoming work will be dedicated to integrate in the modeling approach other physiological processes such as stomatal conductance and carbon partitioning. The improved FSPM could then be used to test different scenarios, for instance in climate change context with low radiations or frequent drought events. Similarly, the model could be used to investigate different planting patterns and intercropping systems, and proposed new multi-criteria ideotypes of oil palm
Vidal, Tiphaine. "Intérêt de la diversité architecturale des plantes cultivées pour limiter la progression épidémique de maladies foliaires à dispersion pluviale : cas de la septoriose au sein d'associations variétales de blé". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLA012/document.
Testo completoGrowing mixtures of susceptible and resistant cultivars in the same field makes it possible to reduce the propagation of airborne fungal plant diseases. Plant architecture has an impact on spore dispersal or microclimate, but is rarely taken into account in mixture design. The objective of this work was to understand the role of canopy architecture in mixtures of cultivar of different levels of resistance to a disease dispersed by rain-splash, septoria tritici blotch, caused by Zymoseptoria tritici. A controlled conditions experiment made it possible to quantify relationships between spore interception and canopy architecture. Differences of canopy density between pure stands and mixtures led to a reduction in disease on susceptible plants grown in mixture, compared to the susceptible pure stand. During a field experiment, mixtures of cultivars with contrasted stem height were less diseased than those with similar stem height. These results were related to the effect of canopy architecture on spore dispersal and leaf wetness duration. A spatially explicit modeling approach made it possible to identify splash dispersal mechanisms related to the architecture of mixed canopies. In mixtures of cultivar with diverse plant height, the amount of splashed inoculum depended on leaf area located above diseased leaves (umbrella effect). The amount of inoculum intercepted by a leaf layer was related to its difference of height between the inoculum sources (height effect). Differences of plant height between cultivars composinga mixture modulated the interception of spores by resistant leaves, providing an increased protection of susceptible leaves (barrier effect). Our results suggest that considering cultivar architecture in the design of cultivar mixtures could make it possible to improve the management of splash-dispersed diseases
Madre, Frédéric. "Biodiversité et bâtiments végétalisés : une approche multi-taxons en paysage urbain". Paris, Muséum national d'histoire naturelle, 2014. http://www.theses.fr/2014MNHN0004.
Testo completoUrbanization destroys and fragments natural ecosystems, contributing to global change and biodiversity loss. This hostile urban matrix mainly consists of roads and buildings. Recently, the buildings are covered with greening systems (introduction of plants on suitable media). These systems provide benefits to humans and reduce the hostility of the matrix making the city more permeable to wildlife. There are various types of greening systems that do not act equal for biodiversity. In this thesis, we analyzed the communities using these potential habitats: (1) wild plants on green roofs, (2) arthropods and birds on green roofs (3) arthropods on vegetated facades and (4) arthropods on vegetated buildings within the urban landscape. We highlighted the importance of the structural complexity of vegetation on the studied communities
Alonso, Marie. "Balance entre reproduction sexuée et asexuée chez le fraisier : vers la construction d’un réseau de gènes contrôlant le devenir du méristème axillaire". Thesis, Bordeaux, 2022. http://www.theses.fr/2022BORD0158.
Testo completoStrawberry is able to reproduce both sexually, via flowering, and asexually, via the production of stolons. The AxM governs these two modes of reproduction since AxM can become a lateral branch terminated by an inflorescence, or a stolon, or remain dormant. Thus, the AxM fate shapes the plant architecture and promotes the fruit yield or daughter plant production. The objective of this thesis is to identify and characterise molecular actors that affect the AxM fate by using the diploid strawberry model. The manuscript is divided into three points:(1) Morphological and histological observation of the early events of the AxM development has allowed to define for the first time in strawberry a scale of the AxM development into a stolon or a lateral branch. This study highlights an undifferentiated stage that is morphologically identical for both types of AxM.(2) A transcriptome study of undifferentiated axillary buds identified 283 differentially expressed genes (DEGs) between those becoming a stolon and becoming a lateral branch. Among the DEGs, we identified FveTCP9, homologous to AtBRC1, and genes involved in the phytohormone and flowering pathways. These genes were chosen for further analysis to investigate their role in the AxM fate.In order to initiate a gene network, a second transcriptomic analysis included the spatio-temporal development of the axillary bud into a lateral branch or a stolon. Results highlighted the effects of the axillary bud position at the node of the primary crown and the developmental stage of the seedling on the transcriptome.(3) The study of the chosen DEGs by using different approaches, qPCR in different genetic backgrounds and/or in situ hybridization, confirmed their role in controlling the AxM fate. Among these genes, the CRISPR-Cas9 mutation of FveTCP9 validates its role in the AXM fate and shows that lateral branches were produced at the expense of stolons.This thesis initiated a regulatory network controlling the fate of MAx and also identified key genes that could be studied in octoploid strawberry for future agronomic applications
Huang, Zhaoheng. "Landscape plants in architectural design". Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/845986.
Testo completoDepartment of Architecture
Alvarez, Flores Ricardo Andrés. "Réponses morphologiques et architecturales du système racinaire au déficit hydrique chez des Chenopodium cultivés et sauvages d'Amérique andine". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20138/document.
Testo completoThe genus Chenopodium comprises about 150 species distributed all around the world and over a wide range of environments. In South America, differents species, either cultivated as C. quinoa Willd. and C. pallidicaule Aellen, or wild as C. hircinum Schrader, are distributed over pedoclimatic gradients from the sea level in Chile, up to an altitude of 4000 m in the altiplano of Bolivia and Peru, on soils more or less thick and rich in nutrients, and under climates from tropical humid to arid and cold. These species are phylogenetically related, and it is generally admitted that C. quinoa was domesticated from C. hircinum and that part of its genome comes from C. pallidicaule. Their wide distribution in natural and crop ecosystems and their more or less strong tolerance to environmental constraints, make this group of species an interesting model for examining the diversity of responses of the plants, in particular facing a low disponibility of resources in the soil. As all the water necessary for the life of the pass through the root system, we focused our interest in the intra- and interspecific variations in the root growth and architecture, and their responses to the water deficit, with the hypothesis that plants from arid habitats or from low-input agrosystems, developed root traits that allowed them to increase the acquisition of resources in the soil. To test this hypothesis we compared the root growth and development in plants of two ecotypes of C. quinoa from more or less arid regions, and of populations of C. pallidicaule and C. hircinum, placed under non-limiting or water deficit growth conditions, in pots and in rhizotrons. The main results of this research show that, despite large differences in biomass production and morphology of the aerial plant part, the studied populations showed the same root typology. They differed by several traits of root architecture and morphology which control the capacity of the plant to explore and exploit the soil resources. Some of these traits, such as the taproot elongation rate, showed a high plasticity in response to the water deficit. Other traits, like the specific root length, were less plastic but showed large interspecific differences. These variations in plant root architecture conforms adaptive syndromes that favor the plant survival in the most limiting environments. Key words : Chenopodium quinoa, Chenopodium hircinum, Chenopodium pallidicaule, root system, root architecture, topological index, ontogeny, rhizotron, root elongation, plant growth analysis, cultivated species, wild species, root growth, root morphology
Baillet, Vincent. "Les décors végétalisés dans l'architecture grecque : le kymation lesbique : analyse, restitution volumétrique et interprétation par l'imagerie numérique". Thesis, Bordeaux 3, 2018. http://www.theses.fr/2018BOR30023.
Testo completoThis thesis puts forward a novel approach who will make cohabit together the use of a modern technology in a conventional archaeological study focused on Greek architecture. The use of 3D modeling in this doctoral project leads undoubtedly to explore new issues in the Greek archeology. To do this, we will consider to the benefits of this technology to archaeological sciences. Indeed, the restitution of an ancient building in 3D, involves questions on the virtual reality that created. 3D modeling is based on the archaeological material altered by the time. That is why, it is necessary to take a step back on a 3D picture that can idealize an archaeological reality. Our study will also apply to provide solutions to overcome these complications of the virtual restitution. Moreover, the 3D rendition of an ancient building is not an end in itself. In other words, this technology must provide a intuitive approach and a new way to understand the issues that affect at the construction of ancient buildings. Starting with the construction methods or architectural feasibility ... etc.. At the same time, we will conduct an architectural and archaeological examination in order to propose a study that is balanced and that can be reused by archaeological research. Our goals are many and this study wants to be ambitious. For this, this study will strive to avoid the pitfall of proposing an approach that is too restrictive. That is why we plan to combine preferably a study several groups of buildings with different functions. Therefore, taking into account a maximum of archaeological situations our study will be more representative, as this will ensure it a greater likelihood of being reused in the archeological studies. This thesis is also an opportunity to discuss issues related to the promotion of cultural heritage. This topic will also be addressed because the sharing of knowledge should not be accessible only to insiders, but it must also be affordable for the general public. This is an essential task that archeology must carry
Maugarny-Calès, Aude. "Towards the elucidation of the CUP-SHAPED COTYLEDON-centered network duringArabidopsis thaliana leaf development". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS385.
Testo completoThroughout their lives, plants are able to produce new axes by differential growth. The formationof such new growth axes depends on the establishment of a boundary domain, which requires the CUPSHAPEDCOTYLEDON 1-3 (CUC) transcription factors. In this work, I used the small outgrowthsformed at the margin of Arabidopsis thaliana leaves as a model to decipher the CUC-centered networkregulating morphogenesis.In the first part of my work, I focused on the events downstream of CUC2, the master regulator ofleaf margin morphogenesis. Using conditional CUC2 expression combined with morphometric analysesand quantification of reporter genes, I showed that CUC2 functions as a primary and quantitative triggerfor morphogenesis. This trigger then acts through multiple relays, which actions spatially and temporallydiffer, and together allow sustained differential growth.In the second part of this work, I identified and characterized upstream regulators of the CUCgenes. In a candidate-based approach, I showed that miR164 and the polycomb complex PRC2 interact totightly control CUC2 expression. Next, I uncovered new potential transcriptional regulators of theCUC/MIR164 genes through a yeast one-hybrid screen followed by an in planta assay. Finally, I initiateda functional study for some of these candidates, which showed that they are general regulators of shootarchitecture. By revealing upstream and downstream components of the CUC-centered network, this workprovides new insights into how boundaries are regulated and how they shape plants
Serouart, Mario. "Intraspecific competition in maize : Observation through in situ phenotyping, in silico modelling, light regime and application to sowing structure optimization". Electronic Thesis or Diss., Avignon, 2024. http://www.theses.fr/2024AVIG0427.
Testo completoAgroecology integrates ecological principles into agriculture to enhance crop resilience by limiting inputs and maximizing efficiency of natural resources or mechanisms. This latter point is the focus of this thesis. Indeed, one option to enhance the performance of agricultural systems is to optimize plant architecture increasing radiation interception efficiency. This improvement could be achieved through a natural mechanism called phenotypic plasticity. In a competitive environment, with high plant density, maize plants optimize their position by adjusting the arrangement of their photosynthetic organs (leaves) based on neighboring plants, through biophysical processes. Thus, a shade reduction dynamic could limit the illuminated surface area lost at the canopy level. Following this hypothesis, this study aims to understand the influence of plant canopy on its ability to intercept light. This involves two levels of study: maize architecture at the individual plant level and the overall population architecture through sowing patterns, defined by density and row spacing. Our analyses rely on both true field trials, to be as close to real conditions (in situ) as possible, and 3D reconstructions of canopy, establishing a radiative balance on these virtual scenes (in silico). Concerning in situ data, they were collected over the three years of thesis. An unique panel of five hybrid was studied under various sowing patterns configurations, creating more or less competitive environments depending on plant density and spacing between them. A set of aerial characteristics was precisely described for each treatment and trial. This was done through manual acquisitions or indirect estimations using high-throughput phenotyping. Special emphasis was placed on genetic and environmental differences in leaf orientations. This focus, on this specific trait, is due not only to its importance in light interception but also to a lack of knowledge identified in the state of the art. For this purpose, we developed an image analysis algorithm to describe the interactions gxE of induced plasticity by modifying row spacing. Subsequently, thanks to this focus and using data from other aerial parameters collected, allometric relationships were used to model (in silico) virtual canopies. These relationships are considered realistic as they explicitly derive from what was observed in the field. In these cases, they are referred as digital twins. This reconstruction method allowed simulating several architectural specificities both at the individual and population levels. Thus, estimating their influence on the light regime to extract ideotypes, i.e., the best theoretical configurations for optimizing yield. Finally, these conclusions were compared to the actual yield measurements from the three years of experiments to study the reliability of the integrative approach on the yield maximization issue. The results of these analyses revealed significant differences both within hybrids and sowing patterns. Particularly in leaf positioning, showing a strong predominance of leaves oriented perpendicularly to the row direction with increasing intra-row competition. However, we found that this behavior ultimately had little influence on light interception thanks to sensitivity analysis (max. 25% importance). However, it turned out that vertical leaf inclination is the main architectural variable that regulates light intensity and its distribution. In this regard, plants with more erectophilic leaves will result in increased canopy photosynthesis. Finally, the configuration of the sowing pattern played a crucial role. According to this thesis work, reducing row spacing systematically had a positive impact on yield, regardless of the density considered. The magnitudes of yield gains involved in narrowing rows are approximately +1.0 to 2.0 t/ha when sowing at high density (>10 plts/m²) and considering relatively short row distances (<0.6m)
Madani, Ikram. "Plasticité du système racinaire du blé en condition de carence en N, P ou K révélée par développement d'une méthodologie de phénotypage intégrant les poils absorbants". Electronic Thesis or Diss., Université de Montpellier (2022-....), 2022. http://www.theses.fr/2022UMONG059.
Testo completoLow macroelement availability in most cultivated soils severely limits crop yields in the absence of fertilization. A better understanding of the adaptation of root systems to nutrient-poor soils, and the exploitation of existing genetic diversity in this field, between species and/or varieties, are likely to contribute to the development of new cultivars and new agronomic practices allowing to limit costly and environmentally polluting chemical fertilization inputs. The architecture of the root system and the production of root hairs at the root-soil interface are major determinants of the capacity of the root system to explore the soil and take up nutrient ions. To date, no methodology has been available to phenotype root hairs in a root system considered entirely. In this thesis, I developed a methodology for global, integrative phenotyping of root systems, including root hairs. An original rhizobox-type device was developed, allowing to acquire high resolution images, for which I developed a computerized analysis procedure associating the free software Ilastik for image segmentation, and the softwares WinRHIZOTM and ImageJ for the analysis of global traits characterizing the root development. After validation of the methodology, the root systems of two wheat genotypes, a cultivated emmer wheat cultivar (T.t. dicoccum, cv Escandia), ancestor of durum wheat, and a landrace of durum wheat (T.t. durum, cv Oued Zenati) were compared with each other and with respect to their response to low phosphate (P), nitrogen (N) or potassium (K) availability. In 15-day-old seedlings (roots ca. 30 cm long), N, P or K deficiencies differentially affected plant growth (biomass allocation between roots and leaves, and preferential development of the root system). All three deficiencies were found to result in an increase in the total surface area of the root system, resulting primarily from an increase in the total surface area of root hairs over the entire root system (reflecting an increase in the density and/or length of hairs over the entire system). The rate of increase in total absorptive root hair area was variable between the two varieties and among limiting elements, stronger under N deficiency conditions in the emmer wheat, and P deficiency in the landrace. All the root responses analyzed, including or not the root hairs, revealed a greater developmental plasticity in response to nutrient deficiency in the ancestral variety. A perspective opened by this work would be to compare this plasticity in different wheat varieties recapitulating the domestication and improvement of this species. I also show that the methodology I have developed can be used to phenotype root responses to biotic conditions (presence of Plant Growth Promoting Rhizobacteria)
Fernique, Pierre. "A statistical modeling framework for analyzing tree-indexed data : application to plant development on microscopic and macroscopic scales". Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20064/document.
Testo completoWe address statistical models for tree-indexed data.Tree-indexed data can be seen as a generalization of path-indexed data since directed path graphs are directed tree graphs where there is at most one child per vertex.In the context of the Virtual Plants team, host team of this thesis, applications of interest focus on plant development and its modulation by environmental and genetic factors.We thus focus on plant developmental applications, both at the microscopic level with the study of the cell lineage in the biological tissue responsible for the plant growth, and at the macroscopic level with the mechanism of production of branches. The catalog of models available for tree-indexed data is far less important than the one available for path-indexed data.This thesis therefore aims at proposing a statistical modeling framework for studying patterns in tree-indexed data.To this end, two different classes of statistical models, Markov and change-point models, are investigated
Dang, Le Anh Tuan. "Ontogenetic variations in leaf traits of the homoblastic species Dipterocarpus alatus under two light conditions at Cat Tien national park, Vietnam". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20236/document.
Testo completoBackground and Aims:Attempts to explain variations in leaf parameters based solely on environmental factors, this will lead to significant errors if the plant shows substantial ontogenetic variations in leaf properties. We evaluated variations in 27 morpho-anatomical leaf traits of Dipterocarpus alatus over six architectural development stages and between axes at a given development stage under two different light conditions. Methods:An architectural analysis was conducted to distinguish precisely and objectively axis categories and developmental stages of Dipterocarpus alatus. Leaves were collected on the most recent complete growth unit on the top of the trunk and the outermost part of the middle-crown branch with branchlet and twig from trees growing under two different light conditions. Twenty two leaf traits were measured and calculated using ImageJ on images of leaf tracings and cross-sections. Stomatal density was calculated on nail varnish impression of the leaf lower surface. Four chlorophyll traits were determined. One-way ANOVA and Tukey post-hoc tests were used to determine differences between development stages and axes. The lmg relative contribution was calculated with R package relaimpo and compared with bootstrap analysis to determine ontogenetic stage, axis category or light intensity, which explained more the variations in leaf anatomy.Key results:Leaf morphology and anatomy differed strongly during ontogeny for all four axes in term of order and category under both light conditions. The axis effect was displayed at stages B, C, D and F but tend to be insignificant at stage E. Tree ontogeny explained more variations in leaf morphology and anatomy than light intensity. Axis category explained more variations in leaf morphology but not in leaf anatomy than tree ontogeny. Conclusions: Strong and significant intraspecific variations (during ontogeny and between axes) may influence the interspecific variations, and thus challenge the validity of the mean value of leaf traits between species. Tree ontogeny contributed more than light intensity in explanation of the variability in leaf morphology and anatomy both on the trunk and second axis order strongly recommends that studies on the responses of leaf anatomy to the environment need to correct for the ontogeny effect
Fournier, Christian. "Modélisation des interactions entre plantes au sein des peuplements. Application à la simulation des régulations de la morphogenèse aérienne du maïs (Zea mays L.) par la compétition pour la lumière". Phd thesis, Institut national agronomique paris-grignon - INA P-G, 2000. http://tel.archives-ouvertes.fr/tel-00003247.
Testo completoL'objectif de la thèse est d'élaborer une modélisation du couvert comme une population de plantes. Ceci nécessite de prendre en compte explicitement le développement de chaque individu au sein du couvert, et ses conséquences sur la croissance des plantes voisines. La thèse a pris pour objet la simulation des effets de la compétition pour la lumière sur la morphogenèse de l'appareil végétatif aérien du maïs (Zea mays L.).
Dans un premier temps, la plasticité morphologique du maïs est étudiée expérimentalement au champ, pour des situations contrastées de compétition pour la lumière. Une forte compétition conduit à une réduction globale de la taille des plantes. Elle a pour effet également d'accentuer au cours du temps la variabilité entre individus. L'analyse des dimensions individuelles des organes montre que la croissance en largeur et en diamètre suit précisément ce schéma. Par contre l'allongement des organes est d'abord stimulé par la compétition, puis subit une réduction dépendante de l'intensité de la compétition.
Ces observations ont justifié le choix du formalisme des L-systèmes ouverts pour l'implémentation du modèle. Cette approche permet une modélisation plante à plante, mais aussi d'intégrer et d'expliciter la croissance de chacun des organes. Le modèle couple des modèles microclimatiques préexistants (calcul de la température et de la distribution du rayonnement) à un modèle architectural et fonctionnel du développement végétatif, élaboré à partir de données bibliographiques. Un schéma de réduction de la croissance par le carbone disponible a été introduit et testé sur sa capacité à rendre compte des effets de la densité de peuplement. Le modèle simule la cinétique du développement à partir de données météorologiques mesurées en réseau et d'une paramétrisation génotypique réduite (5 paramètres). La structure géométrique de la plante est rendue de façon réaliste et simule convenablement l'évolution du taux de couverture du sol. Le modèle rend compte des variations de réduction de dimensions foliaires en fonction du numéro de phytomère, et permet de simuler le développement de l'hétérogénéité dans le couvert.
Ce premier axe de travail montre toutefois l'importance de disposer de formulations plus précises des cinétiques de croissances d'organes. L'allongement de la tige est particulièrement peu documenté dans la bibliographie. Nous avons mené l'étude expérimentale de la cinétique d'allongement des entre-nœuds, en considérant des situations contrastées de disponibilité en rayonnement. Les cinétiques de croissance diffèrent selon les traitements, mais montrent une même organisation. Durant une première période, l'allongement est un processus intégré à l'échelle de plusieurs entre-nœuds, stable au cours du développement. Dans une seconde période, la vitesse d'allongement devient très variable selon le rang et est fortement corrélée à la taille finale. La transition entre les deux périodes semble déclenchée par l'émergence de la gaine hors du cornet. L'évolution des dimensions du cornet au cours du temps pourrait donc être responsable des variations de longueur entre-nœuds entre phytomères.
Ce modèle ouvre des applications originales pour l'aide à l'interprétation d'expérimentation, car il permet de situer dans le temps les croissances de chaque organe et de la relier aux conditions environnementales locales. Le cadre de modélisation permet l'intégration des processus, de l'échelle de l'organe à celle du peuplement. Une meilleure compréhension du déterminisme des régulations des dimensions des organes reste toutefois nécessaire pour envisager l'application au raisonnement de pratiques agricoles. Les résultats obtenus suggèrent l'importance de signalisations environnementales, liées à l'exposition des organes à l'air ou à la lumière, dans ces régulations. Ces perspectives confortent l'intérêt d'une approche architecturale et fonctionnelle de la modélisation du développement.
Peaucelle, Alexis. "Dynamique cellulaire et architecture de la plante". Paris 11, 2006. http://www.theses.fr/2006PA112058.
Testo completoThe shoot apical meristem forms the upper part of the plant. It will for example initiate and determine the position of the lateral organs (phyllotaxy). Despite the high mitotic activity required for organogenesis, the meristem presents a stable organisation in functional multicellular domains. Here, we have characterised cell dynamics of the central zone, organising domain and boundary domain. For this, we have developed a tool for tissue-specific and inducible gene expression using the ethanol switch. Then, we analysed the role of recently discovered regulator of meristem function, miR164. MiR164 is a microRNA that negatively regulates the boundary identity genes CUP-SHAPED COTYLEDON1 et 2 (CUC1 and CUC2). Our results indicate that miR164 maintains the boundary size despite the cell dynamics. By studying plants impaired for miR164-mediated regulation of the CUC genes and the phyllotaxy mutant bellringer (blr), we have demonstrated the existence of a post meristematic mechanism of phyllotaxy control. Finally, we have characterised the cell wall composition of the blr mutant meristem. Our results indicate a potential link between physical stress, resulting from the parietal structure and the position of the primordia. Thus, the meristematic structure is maintained, despite the cell dynamics observed in all its domains, via a complex genetic network and maybe also via the parietal structure regulation
Vestrella, Antonio. "Green roofs in the mediterranean area : ecophysiological and agronomic aspects = Cubiertas ajardinadas en ambiente mediterráneo: aspectos ecofisiológicos y agronómicos". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/386439.
Testo completoEn esta tesis se investigaron los techos verdes extensivos o cubiertas ecológicas en ambiente mediterráneo. Las cubiertas ecológicas son estructuras que se instalan sobre el techo de los edificios y se caracterizan por una capa relativamente delgada de substrato y vegetación con escaso desarrollo. En las últimas décadas las cubiertas verdes se han desarrollado en Norte de América y en el centro y norte de Europa y recientemente han empezado a implantarse en la zona Mediterránea. A pesar de la gran variedad climática presente en el mediterráneo, las diferencias más importantes con el norte de Europa afectan los aspectos térmicos, la variabilidad de las precipitaciones y las condiciones sociales entre otros. A las condiciones de una cubierta ecológica es necesario añadir las grandes diferencias de temperatura entre el día y la noche, los efectos del cambio climático, y la escasez de recursos hídricos propios de la zona mediterránea. Los techos verdes pueden reducir el flujo de agua de lluvia evitando cargar la red de alcantarillado, mejoran el microclima en los edificios (protegen contra el calor estival y las bajas temperaturas invernales), asimismo la menor temperatura de los tejados puede ayudar a disminuir la temperatura en las ciudades y contribuir a la conservación de la diversidad biológica. Los diferentes ensayos que componen esta tesis doctoral se han realizado en Caldes de Montbui (205 m.s.n.m.) (41° 63´ N 2° 16´ E) a 30 km de Barcelona (España) en la sierra pre litoral catalana. Se utilizaron diferentes simulaciones de cubiertas verdes en condiciones de riego mínimo (0% - 20% - 40% ET0). En la primera parte del estudio se evaluó la adaptabilidad de 12 especies en techos verdes mediterráneos. La segunda parte se investigó sobre el comportamiento de las plantas con diferentes formas de crecimiento y la interacción entre ellas. En la última parte se estudió el contenido de humedad y la temperatura del substrato en tres especies vegetales con diferente patrón de crecimiento. Los resultados mostraron que en condiciones de riego mínimo, existen especies que se pueden adaptar en ambiente mediterráneo, obteniendo desarrollo en biomasa, cobertura adecuada y una floración variada. Las diferentes formas de crecimiento han influenciado las especies estudiadas y los comportamientos en las dos simulaciones de cubiertas verdes en diversidad y capacidad de albergar especies colonizadoras o foráneas. La diferente estructura de la biomasa vegetal ha influido en la temperatura y en el contenido de agua del substrato.
Picart, Picolo Ariadna. "L'importance du nucléole et des gènes d'ARN ribosomique 45S dans l'organisation 3D et la stabilité du génome chez Arabidopsis thaliana". Thesis, Perpignan, 2019. http://www.theses.fr/2019PERP0025/document.
Testo completoThe nucleolus is the site of ribosome biogenesis, which begins with the transcription of ribosomal RNA (rRNA) genes. However, the nucleolus is also involved in other cellular processes, such as the 3D genome organization. Thus, genomic regions called NADs for Nucleolus-Associated chromatin Domains, have been identified in animal and plant cells. These regions are mostly heterochromatic and the associated genes tend to be poorly transcribed. One of the objectives of my thesis was to study the involvement of the nucleolus in the 3D genome organization and the transcriptional regulation of genes transcribed by RNA Polymerase II in Arabidopsis thaliana. In addition, only a fraction of rRNA gene copies participates in the process of ribosome biogenesis. In a second time, I studied the role of the inactive rRNA gene copies. We show that in their absence, there is no major changes in the nucleolus function. However, these copies contribute to genome stability. Indeed, in their absence, up to several hundred of kilobases long duplication events accumulate, resulting in the duplication and the differential expression of hundreds of genes. Finally, the impact of these structural changes on the plant biology are discussed
Baccar, Rim. "Plasticité de l'architecture du blé d'hiver modulée par la densité et la date de semis et son effet sur les épidémies de Septoria tritici". Phd thesis, AgroParisTech, 2011. http://pastel.archives-ouvertes.fr/pastel-00741439.
Testo completoOng, Boon Lay. "Place and plants in architecture : an investigation into the phenomenon of place, the thermal environment and the significant role of plants". Thesis, University of Cambridge, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266169.
Testo completoBlackson, Meghan Michelle. "Designing Roofs to Support Native Plants in the Great Lakes Region". Kent State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=kent1619702653699892.
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