Determining the instar of a weevil larva (Coleoptera: Curculionidae) using a parsimonious method

International audienceno abstrac

Vacancy formation in

The defect population is important for understanding the microstructure of δ-plutonium. Using spin-polarized density-functional theory, we calculate the formation energies of monovacancies as well as divacancies. We show that the unrelaxed values are quite independent of the magnetic configuration while atomic relaxations lead to smaller values, relaxation effects being larger for the disordered magnetic structure

MareyMap online: A user-friendly web application and database service for estimating recombination rates using physical and genetic maps

Given the importance of meiotic recombination in biology, there is a need to develop robust methods to estimate meiotic recombination rates. A popular approach, called the Marey map approach, relies on comparing genetic and physical maps of a chromosome to estimate local recombination rates. In the past, we have implemented this approach in an R package called MareyMap, which includes many functionalities useful to get reliable recombination rate estimates in a semi-automated way. MareyMap has been used repeatedly in studies looking at the effect of recombination on genome evolution. Here, we propose a simpler user-friendly web service version of MareyMap, called MareyMap Online, which allows a user to get recombination rates from her/his own data or from a publicly available database that we offer in a few clicks. When the analysis is done, the user is asked whether her/his curated data can be placed in the database and shared with other users, which we hope will make meta-analysis on recombination rates including many species easy in the future

adegraphics: An S4 Lattice-Based Package for the Representation of Multivariate Data

International audienc

Local spin density functional investigations of a manganite with perovskite-type derived structures

The electronic and magnetic structures of the perovskite CaMnO3 are self-consistently calculated assuming two crystal structures at the same formula unit volume within the local spin density functional theory and the augmented spherical wave (ASW) method. From the comparisons of energy differences between the different magnetic states the ground state configuration is an insulator with G-type ordering. This result together with the magnitudes of the magnetic moments are in agreement with experiment. The influence of mixing between Mn and O is found spin dependent from the analysis of the crystal orbital overlap population (COOP) which enable to describe the chemical bond. The calculations underline a feature of a half metallic ferromagnet which could be connected with the colossal magnetoresistance (CMR) property of related compounds

Fruiting Strategies of Perennial Plants: A Resource Budget Model to Couple Mast Seeding to Pollination Efficiency and Resource Allocation Strategies

International audienceMasting, a breeding strategy common in perennial plants, is defined by seed production that is highly variable over years and synchronized at the population level. Resource budget models (RBMs) proposed that masting relies on two processes: (i) the depletion of plant reserves following high fruiting levels, which leads to marked temporal fluctuations in fruiting; and (ii) outcross pollination that synchronizes seed crops among neighboring trees. We revisited the RBM approach to examine the extent to which masting could be impacted by the degree of pollination efficiency, by taking into account various logistic relationships between pollination success and pollen availability. To link masting to other reproductive traits, we split the reserve depletion coefficient into three biological parameters related to resource allocation strategies for flowering and fruiting. While outcross pollination is considered to be the key mechanism that synchronizes fruiting in RBMs, our model counterintuitively showed that intense masting should arise under low-efficiency pollination. When pollination is very efficient, medium-level masting may occur, provided that the costs of female flowering (relative to pollen production) and of fruiting (maximum fruit set and fruit size) are both very high. Our work highlights the powerful framework of RBMs, which include explicit biological parameters, to link fruiting dynamics to various reproductive traits and to provide new insights into the reproductive strategies of perennial plants

Genetic structure and linkage disequilibrium in 4 Vitis species

International audienceTo answer the new challenges faced by viticulture, grapevine breeding major goal is to create new cultivars integrating both resistance against pathogens and adaptation to climatic changes while still offering high quality final products. These traits have to be accumulated from different sources, several Vitis species for resistance to biotic and abiotic stresses and V. vinifera for quality. Compared to other crops, the genetic bases of the variability of these complex traits are still poorly understood in grapevine, in particular because searching for QTLs in perennial woody species is very long, tedious and costly. Applying association genetics at the whole genome scale (genome-scan) will permit to more rapidly and efficiently identify the main genetic factors underlying the variation of agronomically important traits, by taking advantage of the high variability and recombinations accumulated within the available genetic resources. Precise knowledge of the structure of genetic diversity and linkage disequilibrium (LD) in study samples is crucial to design and perform association genetics studies. The DLVitis project aims at producing this knowledge for 4 Vitis species of interest to breeding, V. vinifera and 3 american species, V. riparia, V. cinerea and V. aestivalis. Its main objectives are : - to characterize the structure of genetic diversity within populations of the 3 American species - to characterize LD between SNPs in 4 genomic regions of 2 Mb each, in 4 samples of V. vinifera and 1 population of each of the 3 American species to locally test genome-scan for two traits, resistance to downy mildew and berry size