Genetic control of plasticity of oil yield for combined abiotic stresses using a joint approach of crop modeling and genome-wide association

Understanding the genetic basis of phenotypic plasticity is crucial for predicting and managing climate change effects on wild plants and crops. Here, we combined crop modeling and quantitative genetics to study the genetic control of oil yield plasticity for multiple abiotic stresses in sunflower. First we developed stress indicators to characterize 14 environments for three abiotic stresses (cold, drought and nitrogen) using the SUNFLO crop model and phenotypic variations of three commercial varieties. The computed plant stress indicators better explain yield variation than descriptors at the climatic or crop levels. In those environments, we observed oil yield of 317 sunflower hybrids and regressed it with three selected stress indicators. The slopes of cold stress norm reaction were used as plasticity phenotypes in the following genome-wide association study. Among the 65,534 tested SNP, we identified nine QTL controlling oil yield plasticity to cold stress. Associated SNP are localized in genes previously shown to be involved in cold stress responses: oligopeptide transporters, LTP, cystatin, alternative oxidase, or root development. This novel approach opens new perspectives to identify genomic regions involved in genotype-by-environment interaction of a complex traits to multiple stresses in realistic natural or agronomical conditions.Comment: 12 pages, 5 figures, Plant, Cell and Environmen

Application de la méthode "multiconfiguration time-dependent Hartree" aux processus de photodissociation des complexes ArHBr et Ar2HBr

Cette thèse concerne l'étude théorique, dans un formalisme quantique dépendant du temps, de la photodissociation de la molécule HBr en présence d'un ou de plusieurs atomes d'argon. On s'intéresse plus particulièrement au rôle que jouent les atomes de gaz rare sur le processus de dissociation et en particulier sur un éventuel piégeage de l'atome d'hydrogène encore appelé effet de cage. La méthode MCTDH (Multi Configuration Time-Dependent Hartree) utilisée pour la propagation des paquets d'ondes est une approche de champ moyen dans laquelle chaque degré de liberté est associé à plusieurs orbitales mono-modes qui dépendent du temps et où la fonction d'onde totale qui décrit la dynamique du processus est développée sous la forme d'une combinaison linéaire de produits de Hartree de ces orbitales. L'évolution temporelle des différentes orbitales qui s'adaptent au processus dynamique permet une réduction importante du temps de calcul par rapport a une méthode standard dépendant du temps. Un autre atout majeur de la méthode est une diminution de la place mémoire, essentielle si l'on veut s'intéresser à des systèmes à plus de trois atomes. Dans une première partie, nous étudions, par un calcul quantique 3D, la photodissociation du complexe Ar-HBr. Les évolutions temporelles des probabilités dans les différents modes et les calculs de flux quantique nous permettent de donner une description détaillée de la dynamique du processus. La deuxième partie concerne l'étude de la photodissociation du complexe Ar2-HBr. Nous présentons dans un premier temps les résultats d'un calcul 5D dans lequel nous imposons une contrainte planaire. Afin d'obtenir des renseignements qualitatifs complémentaires sur la physique du processus de fragmentation, nous avons effectué des calculs 3D, en autorisant des grilles plus denses dans le mode Ar2 ou dans le mode Ar2-Br. Enfin nous présentons un résultat préliminaire 3D sur la dissociation du complexe Ar3-HBr.LILLE1-BU (590092102) / SudocSudocFranceF

Premiers terrains : les preuves de réalité ? Analyse des réponses à un questionnaire

Guigou Brigitte, Pouilly Sylvie. Premiers terrains : les preuves de réalité ? Analyse des réponses à un questionnaire. In: Bulletin de l'Association française des anthropologues, n°31, Janvier-Mars 1988. L'ethnologue et son terrain. Tome II. Les cadets, sous la direction de Suzanne Lallemand . pp. 3-33

Étude théorique de la dynamique des collisions réactives (calcul de la probabilité de réaction cumulée N (E))

LILLE1-BU (590092102) / SudocSudocFranceF

Quantum and classical non-adiabatic dynamics of Li₂⁺Ne photodissociation

International audienceThe 3D photodissociation dynamics of Li2+Ne system is investigated by quantum calculations using the multi-configuration time-dependent Hartree (MCTDH) method and by classical simulations with the trajectory surface hopping (TSH) approach. Six electronic states of A' symmetry and two states of A" symmetry are involved in the process. Couplings in the excitation region and two conical intersections in the vicinity of the Franck–Condon zone control the non-adiabatic nuclear dynamics. A diabatic representation including all the states and the couplings is determined. Diabatic and adiabatic populations calculated for initial excitation to pure diabatic and adiabatic states lead to a clear understanding of the mechanisms governing the non-adiabatic photodissociation process. The classical and quantum photodissociation cross-sections for absorption in two adiabatic states of the A' symmetry are calculated. A remarkable agreement between quantum and classical results is obtained regarding the populations and the absorption cross-sections

EXPERIMENTAL AND THEORETICAL INVESTIGATION OF THE ELECTRONIC STRUCTURE OF CaF

$^{1}$B. Rosen (ed.), Spectroscopic Data Relative to Diatomic Molecules Pergamon 1970. $^{2}$D. P. Nanda and B. S. Mohanty, Curr. Sci. (India) 39, 300 (1970).""Author Institution: Department of Chemistry, Massachusetts Institute of Technology; Laboratoire de Spectroscopie des Mol\'ecules Diatomiques, Universit\'e de Lille (I)Optical-optical double resonance experiments on CaF have been performed using two cw dye lasers. The $E^{\prime}{^{2}\Pi} - A^{2}\Pi$ and $A^{2}\Pi - X^{2}\Sigma^{+}$ transitions are sequentially pumped by Rhodamine 110 and 6G dye lasers respectively. The $E^{\prime}{^{2}\Pi}$ state ($T_{0} \sim 34\; 490 cm^{-1}, B_{o} \sim 0.358\;cm^{-1}$) has not been observed previously and a vibration-rotation analysis is in progress. $E^{\prime}{^{2}\Pi} - B^{2}\Sigma^{+}$ fluorescence allows analysis of the $B^{2}\Sigma^{+}$ state [preliminary constants $T_{o} = 18 830(2) cm^{-1}, w_{e} = 571.5(5), w_{e} x_{3} = 3.0(2), B_{o} = 0.3439(5)\;cm^{-1}$. The differences between these constants and those in $Rosen^{1}$ are due to a large separation between bandheads and origins and to an error in the previous B-X rotational $analysis^{2}$ In addition, the double resonance fluorescence spectrum contains a cascade $Z-A^{2}\Pi$ transition. The Z state is either $^{2}\Sigma$ or $^{2}\Delta$ and has $T_{o} \sim 30 170\;cm^{-1}, B_{o} = 0.362\;cm^{-1}$. Semi-empirical and SCF-CI calculations of the electronic structure of CaF will be discussed with particular emphasis on the location on the lowest energy $^{2}\Delta$ state

Photodissociation of a HCl molecule adsorbed on ice at T=210K

International audienceThis theoretical work concerns the study of the photodissociation of a HCl molecule adsorbed on an ice surface at T = 210 K. Temperature induced disorder is taken into account by a statistics over several configurations extracted from a classical molecular dynamics (MD) simulation. For each configuration, 3D quantum dynamics of the hydrogen photofragment is investigated using the multi-configuration time-dependent Hartree (MCTDH) method. The absorption spectrum at 210 K is obtained by an average over the spectra calculated for each configuration. The surface disorder results in a smoothing of the interferences structures that appear for some given orientations of HCl depending on the surrounding water molecules orientations

Molecular diversity of sunflower populations maintained as genetic resources is affected by multiplication processes and breeding for major traits.

The molecular diversity in a set of 114 cultivated sunflower populations was studied by single-nucleotide polymorphism genotyping. These populations were chosen as representative of the 400 entries in the INRA collection received or developed between 1962 and 2011 and made up of land races, open-pollinated varieties, and breeding pools. Mean allele number varied from 1.07 to 1.90. Intra population variability was slightly reduced according to the number of multiplications since entry but some entries were probably largely homozygous when received. A principal component analysis was used to study inter-population variability. The first 3 axes accounted for 17% of total intra-population variability. The first axis was significantly correlated with seed oil content, more closely than just the distinction between oil and confectionary types. The second axis was related to the presence or absence of restorer genes and the third axis to flowering date and possibly to adaptation to different climates. Our results provide argument shighlighting the effect of the maintenance process on the within population genetic variability as well as on the impact of breeding for major agronomic traits on the between population variability of the collection. Propositions are made to improve sunflower population maintenance procedures to keep maximum genetic variability for future breeding