NobleBlocks

GEVES

otherBeaucouzé, France

Research output, citation impact, and the most-cited recent papers from GEVES. Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
486
Citations
9.7K
h-index
54
i10-index
191
Also known as
GEVESGroup for the Study and Control of Varieties and SeedsGroupe d'étude et de contrôle des variétés et des semences

Top-cited papers from GEVES

Arabidopsis cell wall composition determines disease resistance specificity and fitness
Antonio Molina, Eva Miedes, Laura Bacete, J. Tinguaro Rodríguez +4 more
2021· Proceedings of the National Academy of Sciences185doi:10.1073/pnas.2010243118

Significance Plant cells are surrounded by an extracellular matrix known as the cell wall. We have analyzed the contribution of the Arabidopsis cell wall to disease resistance to pathogens with different parasitic styles. Here, we demonstrate that plant cell walls are determinants of immune responses since modification of their composition in a set of Arabidopsis cell wall mutants has an impact on their disease resistance and fitness phenotypes. In these genotypes, we identified specific correlations between the amounts of specific wall carbohydrate epitopes and disease resistance/fitness phenotypes through mathematical analyses. These data support the relevant and specific function of plant cell wall composition in plant immune responses and provide the basis for using wall traits in crop breeding programs.

Genetic Relationships and Fingerprinting of Rapeseed Cultivars by AFLP: Consequences for Varietal Registration
Vincent Lombard, C. P. Baril, Pierre Dubreuil, Francoise Blouet +1 more
2000· Crop Science155doi:10.2135/cropsci2000.4051417x

At present, registration and protection of rapeseed (Brassica napus L.) cultivars relies on a small number of morphological traits. As the number of cultivars increases, the ability to distinguish them on the basis of these traits becomes more difficult. New descriptors like molecular markers are required to maintain the efficiency of registration testing. The objectives of this study were to (i) evaluate the discrimination power of 17 amplified fragment length polymorphism (AFLP) primer combinations tested on a collection of 83 spring and winter rapeseed cultivars, (ii) assess the structure of the genetic diversity revealed by AFLPs, and (iii) compare three genetic distance estimators (Jaccard, Sokal, and Michener and Sokal and Michener weighted by the PIC). A total of 324 polymorphic markers were scored, with an average of 19.1 markers per primer combination. The use of only two primer combinations was sufficient to identify uniquely all the cultivars. The analysis of the genetic structure of the diversity by cluster and principal component analyses and AMOVAs (analyses of molecular variance) clearly delineated three significant factors: the cultivar type (winter or spring), the country of origin (France or Germany), and the breeding company. The three measures of genetic distance were highly correlated (P < 0.001, r = 0.96–0.98) and led to similar groupings. AFLPs were shown to be a powerful method for identifying cultivars and analyzing the genetic structure of the diversity in rapeseed.

Seed mortality in the soil is related to seed coat thickness
Antoine Gardarin, Carolyne Dürr, M. R. Mannino, Hugues Busset +1 more
2010· Seed Science Research148doi:10.1017/s0960258510000255

Abstract Models that quantify the effects of cropping systems on weed dynamics are useful tools for testing innovative cropping systems. In these models, seed mortality in the soil is a key parameter to account for the cumulated effect of cropping systems over time via the soil seed-bank. Since seed mortality is difficult to measure, our objective was to develop a method to estimate it from easily accessible information. Seeds of 13 weed species were buried 30 cm deep in fields and were recovered regularly for 2 years to measure their viability. Seed mass, dimensions, shape, and protein and lipid contents as well as coat thickness were measured. To estimate seed mortality of species not included in the study, we searched for relationships between mortality rates and seed traits. Seed viability mainly decreased during the second year of burial, with mortality rates ranging from 0.01 to 0.63 seeds·seeds− 1·year− 1, depending on the species. Seed mortality decreased with increasing seed coat thickness. No correlation was found with other measured traits or with seed persistence data in the literature. These results were confirmed when the effects of phylogenetic relatedness with phylogenetically independent contrasts were included. The thickness of the seed coat, which varied between 17 and 231 μm over the range of species studied, can protect the seed from external attacks in the soil and slow down seed decay. This trait can be easily measured via X-ray images and could be used to estimate the seed mortality rate for a wider range of species.

Genome-wide association mapping unravels the genetic control of seed germination and vigor in Brassica napus
Sarah Hatzig, Matthias Frisch, Frank Breuer, Nathalie Nési +4 more
2015· Frontiers in Plant Science142doi:10.3389/fpls.2015.00221

Rapid and uniform seed germination is a crucial prerequisite for crop establishment and high yield levels in crop production. A disclosure of genetic factors contributing to adequate seed vigor would help to further increase yield potential and stability. Here we carried out a genome-wide association study in order to define genomic regions influencing seed germination and early seedling growth in oilseed rape (Brassica napus L.). A population of 248 genetically diverse winter-type B. napus accessions was genotyped with the Brassica 60k SNP Illumina genotyping array. Automated high-throughput in vitro phenotyping provided extensive data for multiple traits related to germination and early vigor, such as germination speed, absolute germination rate and radicle elongation. The data obtained indicate that seed germination and radicle growth are strongly environmentally dependent, but could nevertheless be substantially improved by genomic-based breeding. Conditions during seed production and storage were shown to have a profound effect on seed vigor, and a variable manifestation of seed dormancy appears to contribute to differences in germination performance in B. napus. Several promising positional and functional candidate genes could be identified within the genomic regions associated with germination speed, absolute germination rate, radicle growth and thousand seed weight. These include B. napus orthologs of the Arabidopsis thaliana genes SNOWY COTYLEDON 1 (SCO1), ARABIDOPSIS TWO-COMPONENT RESPONSE REGULATOR (ARR4), and ARGINYL-t-RNA PROTEIN TRANSFERASE 1 (ATE1), which have been shown previously to play a role in seed germination and seedling growth in A. thaliana.

GeoTrackNet —A Maritime Anomaly Detector Using Probabilistic Neural Network Representation of AIS Tracks and A Contrario Detection
Duong Nguyen, Rodolphe Vadaine, Guillaume Hajduch, René Garello +1 more
2021· IEEE Transactions on Intelligent Transportation Systems130doi:10.1109/tits.2021.3055614

Representing maritime traffic patterns and detecting anomalies from them are key to vessel monitoring and maritime situational awareness. We propose a novel approach—referred to asGeoTrackNet—for maritime anomaly detection from AIS data streams. Our model exploits state-of-the-art neural network schemes to learn a probabilistic representation of AIS tracks anda contrariodetection to detect abnormal events. The neural network provides a new means to capture complex and heterogeneous patterns in vessels’ behaviours, while thea contrariodetector takes into account the fact that the learnt distribution may be location-dependent. Experiments on a real AIS dataset comprising more than 4.2 million AIS messages demonstrate the relevance of the proposed method compared with state-of-the-art schemes.

Transforming plant-based waste and by-products into valuable products using various “Food Industry 4.0” enabling technologies: A literature review
Abderrahmane Aït‐Kaddour, Abdo Hassoun, Inès Tarchi, M. Loudiyi +4 more
2024· The Science of The Total Environment127doi:10.1016/j.scitotenv.2024.176872

The last several years have seen unprecedented strain on food systems as a result of pandemics, climate change, population growth, and urbanization. Thus, academic and scientific communities now view global food security as a critical issue. However, food loss and waste are a major challenge when adopting food security and sustainability strategies, since a large proportion of food is lost or wasted along the food supply chain. In order to use resources efficiently and enhance food security and sustainability, food waste and by-products must be reduced and properly valorized. Plant-based food production generates various by-products which are generally rich in nutrients and bioactive compounds. Emerging technologies have been effectively employed to extract these valuable compounds with health benefits. Recently, Industry 4.0 technologies such as artificial intelligence, the Internet of Things, blockchain, robotics, smart sensors, 3D printing, and digital twins have a great deal of potential for waste reduction and by-products valorization in food industry. Reducing food waste not only benefits the environment, but also reduces greenhouse gas emissions and thus contributes to sustainable resource management. This review provides up-to-date information on the potential of Industry 4.0 for converting plant-based waste and by-products into valuable products. Recent studies showed that innovations in Industry 4.0 provide attractive opportunities to increase the effectiveness of manufacturing operations and improve food quality, safety and traceability. By leveraging Food Industry 4.0, companies can transform plant-based waste and by-products into valuable products and contribute to a more sustainable and efficient food production system.

Population sex ratio variation in a monogamous long‐lived bird, the wandering albatross
Henri Weimerskirch, Joëlle Lallemand, Julien Martin
2005· Journal of Animal Ecology121doi:10.1111/j.1365-2656.2005.00922.x

Summary Factors affecting population birth sex ratio and variations of sex ratios within population in very long‐lived animals are poorly known, apart for humans that have attracted much attention. We measured the age and sex structure of a population of a monogamous long‐lived seabird, the wandering albatross Diomedea exulans, where reproductive performance of individuals is known, to examine factors affecting sex ratio variation and survival consequences of producing a particular sex. The overall sex ratio at hatching is significantly biased toward the production of males. Very young and old parents tend to produce an excess of female offsprings, whereas intermediate‐aged birds, which represent the bulk of the population, produce an excess of males. Low‐quality parents (quality is measured as average breeding success over the cumulated past breeding life, and is not related to condition or age) produce more female chicks compared with high‐quality parents that represent the bulk of the population. The combined effect of age and quality of parents produce an extensive sex ratio variation at the level of the population. The survival of male and female parents is influenced differently by their quality and by the sex of offspring. Male parents die in larger numbers when rearing a female chick, whereas low‐quality female parents have a lower survival, especially when they rear a male offspring, the sex needing higher parental investment. The differences between males and females parents’ survival are probably due their contrasted investment in parental care. After fledging, during the 5–8‐year period of immaturity, there is a much higher mortality of males that balances the surplus of males at hatching and fledging and results in a similar number of males and females at the time of recruitment. However, the overall operational sex ratio is male biased due to the slightly higher mortality of adult females that results in an excess of old widowed males: excluding these post‐reproductive males leads to an unbiased operational sex ratio. These results show that sex ratio at hatching varies extremely with the age and phenotypic quality of parents, and lead to a complex age and sex structure of the population in this strictly monogamous long‐lived species.

Development and evaluation of robust molecular markers linked to disease resistance in tomato for distinctness, uniformity and stability testing
Paul F. P. Arens, Carmen Aldea Mansilla, Daniël Deinum, Laetitia Cavellini +4 more
2009· Theoretical and Applied Genetics113doi:10.1007/s00122-009-1183-2

Molecular markers linked to phenotypically important traits are of great interest especially when traits are difficult and/or costly to be observed. In tomato where a strong focus on resistance breeding has led to the introgression of several resistance genes, resistance traits have become important characteristics in distinctness, uniformity and stability (DUS) testing for Plant Breeders Rights (PBR) applications. Evaluation of disease traits in biological assays is not always straightforward because assays are often influenced by environmental factors, and difficulties in scoring exist. In this study, we describe the development and/or evaluation of molecular marker assays for the Verticillium genes Ve1 and Ve2, the tomato mosaic virus Tm1 (linked marker), the tomato mosaic virus Tm2 and Tm2 ( 2 ) genes, the Meloidogyne incognita Mi1-2 gene, the Fusarium I (linked marker) and I2 loci, which are obligatory traits in PBR testing. The marker assays were evaluated for their robustness in a ring test and then evaluated in a set of varieties. Although in general, results between biological assays and marker assays gave highly correlated results, marker assays showed an advantage over biological tests in that the results were clearer, i.e., homozygote/heterozygote presence of the resistance gene can be detected and heterogeneity in seed lots can be identified readily. Within the UPOV framework for granting of PBR, the markers have the potential to fulfil the requirements needed for implementation in DUS testing of candidate varieties and could complement or may be an alternative to the pathogenesis tests that are carried out at present.

Genetic linkage mapping of quantitative trait loci for behavioral and neuroendocrine stress response traits in pigs
Céline Désautés, Jean Pierre Bidanel, Denis Milan, Nathalie Iannuccelli +4 more
2002· Journal of Animal Science113doi:10.2527/2002.8092276x

A QTL analysis of behavioral and neuroendocrine responses to a "novel environment" stress was conducted in a three-generation experimental cross between Meishan and Large White pig breeds. A total of 186 F2 males and 182 F2 females were studied for their behavioral and neuroendocrine reactivity to a novel environment test at 6 wk of age. Locomotion, vocalization, and defecation rate, as well as exploration time, were measured for 10 min. Blood samples were taken immediately before and after the test to measure plasma levels of ACTH, cortisol, and glucose. Animals were typed for a total of 137 markers covering the entire porcine genome. Analyses were performed using two interval mapping methods: a line-cross regression method, where founder lines were assumed to be fixed for different QTL alleles, and a half-/full-sib maximum likelihood method where allele substitution effects were estimated within each half-/full-sib family. Both methods revealed a highly significant gene effect for poststress cortisol level (P < 0.001) and a significant effect for basal cortisol level (P < 0.05) at the end of the q arm of chromosome 7, explaining, respectively, 20% and 7% of the phenotypic variance. Meishan alleles are associated with higher cortisol levels and are partially dominant (for poststress levels) over Large White alleles. Other significant gene effects on biological measures were detected on chromosomes 1 and 17 (ACTH response to stress), 3, 5, and 8 (glucose levels). The SSC 17 QTL explains 12% of the phenotypic variance of poststress ACTH levels, with a suggestive evidence of imprinting effects. Meishan alleles are associated with lower poststress ACTH levels. Gene effects of low amplitude only were found for behavioral reactivity traits. Considering the effects of stress neuroendocrine systems on energy fluxes and protein deposition, and the importance of stress reactivity for meat quality and animal welfare, these results open new perspectives for pig selection.

Evaluation of seed quality: from physiology to international standardization
Stan Matthews, Enrico Noli, İ. Demir, Mohammad Khajeh-Hosseini +1 more
2012· Seed Science Research104doi:10.1017/s0960258511000365

Abstract Seed quality standards enable seed users to achieve their objectives in the establishment of uniform seedlings to a high and reliable level for a range of agricultural and horticultural crops, growing systems and market outlets. Quality standards of commercial seed lots are determined by their positions on the seed survival curves and the shape of their germination progress curves. Although comparative descriptions of germination curves can be achieved by the calculation of the mean germination time (MGT; delay to radicle emergence), single early counts of radicle emergence provide a convenient means of predicting MGT and differences between seed lots. Evidence is presented for an ageing and metabolic repair hypothesis as the overall physiological basis to explain the principles behind the standard germination and vigour tests (ageing, electrolyte leakage, cold test, germination rate and seedling size). The work of the International Seed Testing Association (ISTA) in developing convenient, inexpensive and internationally repeatable tests is illustrated.

Phylogenetic Analysis and Polyphasic Characterization of Clavibacter michiganensis Strains Isolated from Tomato Seeds Reveal that Nonpathogenic Strains Are Distinct from C. michiganensis subsp. michiganensis
Marie‐Agnès Jacques, Karine Durand, Geoffrey Orgeur, Samuel Balidas +4 more
2012· Applied and Environmental Microbiology99doi:10.1128/aem.02158-12

The genus Clavibacter comprises one species and five subspecies of plant-pathogenic bacteria, four of which are classified as quarantine organisms due to the high economic threat they pose. Clavibacter michiganensis subsp. michiganensis is one of the most important pathogens of tomato, but the recommended diagnostic tools are not satisfactory due to false-negative and/or -positive results. To provide a robust analysis of the genetic relatedness among a worldwide collection of C. michiganensis subsp. michiganensis strains, relatives (strains from the four other C. michiganensis subspecies), and nonpathogenic Clavibacter-like strains isolated from tomato, we performed multilocus sequence-based analysis and typing (MLSA and MLST) based on six housekeeping genes (atpD, dnaK, gyrB, ppK, recA, and rpoB). We compared this "framework" with phenotypic and genotypic characteristics such as pathogenicity on tomato, reaction to two antisera by immunofluorescence and to five PCR identification tests, and the presence of four genes encoding the main C. michiganensis subsp. michiganensis pathogenicity determinants. We showed that C. michiganensis subsp. michiganensis is monophyletic and is distinct from its closest taxonomic neighbors. The nonpathogenic Clavibacter-like strains were identified as C. michiganensis using 16S rRNA gene sequencing. These strains, while cross-reacting with C. michiganensis subsp. michiganensis identification tools, are phylogenetically distinct from the pathogenic strains but belong to the C. michiganensis clade. C. michiganensis subsp. michiganensis clonal complexes linked strains from highly diverse geographical origins and also strains isolated over long periods of time in the same location. This illustrates the importance of seed transmission in the worldwide dispersion of this pathogen and its survival and adaptation abilities in a new environment once introduced.

Determination of Germination Response to Temperature and Water Potential for a Wide Range of Cover Crop Species and Related Functional Groups
Hélène Tribouillois, Carolyne C. Durr, Didier Demilly, Marie-Hélène Wagner +1 more
2016· PLoS ONE98doi:10.1371/journal.pone.0161185

A wide range of species can be sown as cover crops during fallow periods to provide various ecosystem services. Plant establishment is a key stage, especially when sowing occurs in summer with high soil temperatures and low water availability. The aim of this study was to determine the response of germination to temperature and water potential for diverse cover crop species. Based on these characteristics, we developed contrasting functional groups that group species with the same germination ability, which may be useful to adapt species choice to climatic sowing conditions. Germination of 36 different species from six botanical families was measured in the laboratory at eight temperatures ranging from 4.5-43°C and at four water potentials. Final germination percentages, germination rate, cardinal temperatures, base temperature and base water potential were calculated for each species. Optimal temperatures varied from 21.3-37.2°C, maximum temperatures at which the species could germinate varied from 27.7-43.0°C and base water potentials varied from -0.1 to -2.6 MPa. Most cover crops were adapted to summer sowing with a relatively high mean optimal temperature for germination, but some Fabaceae species were more sensitive to high temperatures. Species mainly from Poaceae and Brassicaceae were the most resistant to water deficit and germinated under a low base water potential. Species were classified, independent of family, according to their ability to germinate under a range of temperatures and according to their base water potential in order to group species by functional germination groups. These groups may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods. Our data can also be useful as germination parameters in crop models to simulate the emergence of cover crops under different pedoclimatic conditions and crop management practices.

QTL analysis of seed germination and pre-emergence growth at extreme temperatures in Medicago truncatula
Paula Menna Barreto Dias, Sophie Brunel‐Muguet, Carolyne Dürr, Thierry Huguet +3 more
2010· Theoretical and Applied Genetics76doi:10.1007/s00122-010-1458-7

Enhancing the knowledge on the genetic basis of germination and heterotrophic growth at extreme temperatures is of major importance for improving crop establishment. A quantitative trait loci (QTL) analysis was carried out at sub- and supra-optimal temperatures at these early stages in the model Legume Medicago truncatula. On the basis of an ecophysiological model framework, two populations of recombinant inbred lines were chosen for the contrasting behaviours of parental lines: LR5 at sub-optimal temperatures (5 or 10°C) and LR4 at a supra-optimal temperature (20°C). Seed masses were measured in all lines. For LR5, germination rates and hypocotyl growth were measured by hand, whereas for LR4, imbibition and germination rates as well as early embryonic axis growth were measured using an automated image capture and analysis device. QTLs were found for all traits. The phenotyping framework we defined for measuring variables, distinguished stages and enabled identification of distinct QTLs for seed mass (chromosomes 1, 5, 7 and 8), imbibition (chromosome 4), germination (chromosomes 3, 5, 7 and 8) and heterotrophic growth (chromosomes 1, 2, 3 and 8). The three QTL identified for hypocotyl length at sub-optimal temperature explained the largest part of the phenotypic variation (60% together). One digenic interaction was found for hypocotyl width at sub-optimal temperature and the loci involved were linked to additive QTLs for hypocotyl elongation at low temperature. Together with working on a model plant, this approach facilitated the identification of genes specific to each stage that could provide reliable markers for assisting selection and improving crop establishment. With this aim in view, an initial set of putative candidate genes was identified in the light of the role of abscissic acid/gibberellin balance in regulating germination at high temperatures (e.g. ABI4, ABI5), the molecular cascade in response to cold stress (e.g. CBF1, ICE1) and hypotheses on changes in cell elongation (e.g. GASA1, AtEXPA11) with changes in temperatures based on studies at the whole plant scale.

High diversity of oilseed rape pollen clouds over an agro‐ecosystem indicates long‐distance dispersal
Céline Devaux, Claire Lavigne, Hélène Falentin, Sonia Vautrin +2 more
2005· Molecular Ecology74doi:10.1111/j.1365-294x.2005.02554.x

Abstract Estimating the frequency of long-distance pollination is important in cultivated species, particularly to assess the risk of gene transfer following the release of genetically modified crops. For this purpose, we estimated the diversity and origin of fertilizing pollen in a 10 x 10 km French oilseed rape production area. First, the cultivar grown in each field was identified through surveys to farmers and using microsatellite markers. Examination of the seed set in fields indicated high rates of seed contamination (8.7%) and pollination from other sources (5%). Then, male-sterile plants were scattered over the study area and their seed genotyped using the same markers. Most pollination was local: 65% of the seeds had a compatible sire in the closest field, i.e. at 50 or 300 m depending on site, but the nearest compatible field was found more than 1000 m away for 13% of the seeds. To assess the diversity of fertilizing pollen, each seed was assigned to the nearest putative siring cultivar. The observed diversity of pollen was then compared to that predicted by simulations using three empirical dispersal models with increasing proportion of long-distance pollination. The diversity was sensitive to the dispersal kernel used in the simulations, fatter-tailed functions predicting higher diversities. The dispersal kernel that was more consistent with our data predicted more long-distance dispersal than the exponential function.

Utilization of computer vision and multispectral imaging techniques for classification of cowpea (Vigna unguiculata) seeds
Gamal M. ElMasry, N. S. Mandour, Marie-Hélène Wagner, Didier Demilly +3 more
2019· Plant Methods71doi:10.1186/s13007-019-0411-2

The traditional methods for evaluating seeds are usually performed through destructive sampling followed by physical, physiological, biochemical and molecular determinations. Whilst proven to be effective, these approaches can be criticized as being destructive, time consuming, labor intensive and requiring experienced seed analysts. Thus, the objective of this study was to investigate the potential of computer vision and multispectral imaging systems supported with multivariate analysis for high-throughput classification of cowpea ( Vigna unguiculata ) seeds. An automated computer-vision germination system was utilized for uninterrupted monitoring of seeds during imbibition and germination to identify different categories of all individual seeds. By using spectral signatures of single cowpea seeds extracted from multispectral images, different multivariate analysis models based on linear discriminant analysis (LDA) were developed for classifying the seeds into different categories according to ageing, viability, seedling condition and speed of germination. The results revealed that the LDA models had good accuracy in distinguishing ‘Aged’ and ‘Non-aged’ seeds with an overall correct classification (OCC) of 97.51, 96.76 and 97%, ‘Germinated’ and ‘Non-germinated’ seeds with OCC of 81.80, 79.05 and 81.0%, ‘Early germinated’, ‘Medium germinated’ and ‘Dead’ seeds with OCC of 77.21, 74.93 and 68.00% and among seeds that give ‘Normal’ and ‘Abnormal’ seedlings with OCC of 68.08, 64.34 and 62.00% in training, cross-validation and independent validation data sets, respectively. Image processing routines were also developed to exploit the full power of the multispectral imaging system in visualizing the difference among seed categories by applying the discriminant model in a pixel-wise manner. The results demonstrated the capability of the multispectral imaging system in the ultraviolet, visible and shortwave near infrared range to provide the required information necessary for the discrimination of individual cowpea seeds to different classes. Considering the short time of image acquisition and limited sample preparation, this stat-of-the art multispectral imaging method and chemometric analysis in classifying seeds could be a valuable tool for on-line classification protocols in cost-effective real-time sorting and grading processes as it provides not only morphological and physical features but also chemical information for the seeds being examined. Implementing image processing algorithms specific for seed quality assessment along with the declining cost and increasing power of computer hardware is very efficient to make the development of such computer-integrated systems more attractive in automatic inspection of seed quality.

Genetic resources collections of leafy vegetables (lettuce, spinach, chicory, artichoke, asparagus, lamb’s lettuce, rhubarb and rocket salad): composition and gaps
R. van Treuren, P. Coquin, U. Lohwasser
2011· Genetic Resources and Crop Evolution69doi:10.1007/s10722-011-9738-x

Lettuce, spinach and chicory are generally considered the main leafy vegetables, while a fourth group denoted by ‘minor leafy vegetables’ includes, amongst others, rocket salad, lamb’s lettuce, asparagus, artichoke and rhubarb. Except in the case of lettuce, central crop databases of leafy vegetables were lacking until recently. Here we report on the update of the international Lactuca database and the development of three new central crop databases for each of the other leafy vegetable crop groups. Requests for passport data of accessions available to the user community were addressed to all known European collection holders and to the main collection holders located outside Europe. Altogether, passport data of 17,530 accessions from a total of 129 collections were collected. The four separate databases were made available on line via a common entry page accessible at http://documents.plant.wur.nl/cgn/pgr/LVintro/ . Based on a literature study, an analysis of the gene pool structure of the crops was performed and an inventory was made of the distribution areas of the species involved. The results of these surveys were related to the contents of the newly established databases in order to identify the main collection gaps. Priorities are presented for future germplasm acquisition aimed at improving the coverage of the crop gene pools in ex situ collections.

How do seed and seedling traits influence germination and emergence parameters in crop species? A comparative analysis
Antoine Gardarin, Françoise Coste, Marie-Hélène Wagner, Carolyne Dürr
2016· Seed Science Research61doi:10.1017/s0960258516000210

Abstract Early plant establishment through seed germination and seedling emergence is a crucial process that determines seedling number, emergence time distribution and the early growth of seedlings, all of which are affected by soil climate and soil structure. In the current context of climate change, in which increasing the diversity of cultivated species is considered desirable, and new tillage practices are considerably modifying top-soil surface characteristics, we need to improve our ability to model the effects of the environment on plant establishment. Using a trait-based and model-based framework, we aimed to identify general relationships between seed and seedling traits (e.g. seed mass and lipid content, seedling diameter, base temperature) and germination and emergence model parameters (e.g. time to mid-germination, shoot elongation rate) measured for 18 genotypes belonging to 14 species. Relationships were also investigated among model parameters or traits. Germination rates were faster for species with a high base temperature and for species with seed reserves located principally in the embryo (rather than the endosperm or perisperm). During heterotrophic growth, maximal shoot length and elongation rate increased with seed dry mass. The sensitivity of seedlings to soil obstacles was negatively related to shoot diameter. Thus apart from the known effects of seed mass on seedling establishment, we found that seed reserve location, seedling shoot diameter and shape affected germination rate and emergence success. Such generic rules linking plant traits to germination and emergence parameters enhance our understanding of the determinants of environmental effects on plant establishment success.

Genetic Structure of a Worldwide Germplasm Collection of Prunus armeniaca L. Reveals Three Major Diffusion Routes for Varieties Coming From the Species’ Center of Origin
Hédia Bourguiba, Ivan Scotti, Christopher Sauvage, Tetyana N. Zhebentyayeva +4 more
2020· Frontiers in Plant Science60doi:10.3389/fpls.2020.00638

The characterization of the largest worldwide representative data set of apricot (Prunus armeniaca L.) germplasm was performed using molecular markers. Genetic diversity and structure of the cultivated apricot genetic resources were analysed to decipher the history of diffusion of this species around the world. A common set of 25 microsatellite markers was used for genotyping a total of 890 apricot accessions in different collections from the centre of origin to the more recent regions of apricot culture. Using a Bayesian model-based clustering approach, the apricot genotypes can be structured into five different genetic clusters (FST = 0.174), correlated with the geographical regions of origin of the accessions. Accessions from China and Central Asia were clustered together and exhibited the highest levels of diversity, confirming an origin in this region. A loss of genetic diversity was observed from the centre of origin to both western and eastern zones of recent apricot culture. Altogether, our results revealed that apricot spread from China and Central Asia, defined as the centre of origin, following three major diffusion routes with a decreasing gradient of genetic variation in each geographical groups. The identification of specific alleles outside the centre of origin confirmed the existence of different secondary apricot diversification centres. The present work provides more understanding of the worldwide history of apricot species diffusion as well as the field of conservation of the available genetic resources. Data have been used to define an apricot core collection based on molecular marker diversity which will be useful for further identification of genomic regions associated with commercially important horticultural traits through genome-wide association studies to sustain apricot breeding programs.

Seedling microbiota engineering using bacterial synthetic community inoculation on seeds
Gontran Arnault, Coralie Marais, Anne Préveaux, Martial Briand +4 more
2024· FEMS Microbiology Ecology58doi:10.1093/femsec/fiae027

Synthetic Communities (SynComs) are being developed and tested to manipulate plant microbiota and improve plant health. To date, only few studies proposed the use of SynCom on seed despite its potential for plant microbiota engineering. We developed and presented a simple and effective seedling microbiota engineering method using SynCom inoculation on seeds. The method was successful using a wide diversity of SynCom compositions and bacterial strains that are representative of the common bean seed microbiota. First, this method enables the modulation of seed microbiota composition and community size. Then, SynComs strongly outcompeted native seed and potting soil microbiota and contributed on average to 80% of the seedling microbiota. We showed that strain abundance on seed was a main driver of an effective seedling microbiota colonization. Also, selection was partly involved in seed and seedling colonization capacities since strains affiliated to Enterobacteriaceae and Erwiniaceae were good colonizers while Bacillaceae and Microbacteriaceae were poor colonizers. Additionally, the engineered seed microbiota modified the recruitment and assembly of seedling and rhizosphere microbiota through priority effects. This study shows that SynCom inoculation on seeds represents a promising approach to study plant microbiota assembly and its consequence on plant fitness.

Influence of Environment and Host Plant Genotype on the Structure and Diversity of the Brassica napus Seed Microbiota
Aude Rochefort, Martial Briand, Coralie Marais, Marie-Hélène Wagner +4 more
2019· Phytobiomes Journal56doi:10.1094/pbiomes-06-19-0031-r

Seeds are involved in the transmission of microorganisms from one plant generation to the next and consequently act as reservoirs for the plant microbiota. The driving processes influencing seed microbiota assemblage have not been yet deciphered because of confounding factors related to environmental location, agricultural practices, and host genotype selection. Nine genotypes were chosen among a large panel of genetically diverse Brassica napus accessions. The taxonomic structure of the seed microbiota was monitored by amplification and subsequent high-throughput sequencing of gyrB and internal transcribed spacer 1 markers for two successive years on seed lots collected from self-pollinated plants. Seed germination capacities were compared between all seed lots. Although harvesting year was the main driver of seed microbiota composition, the host genotype also significantly altered the structure of seed microbial assemblages. The core microbiota of B. napus included nine fungal taxa shared between all the genotypes and years, while no bacterial taxa were conserved across all genotypes and years. The harvesting year had the major effect on seed germination but with some differences between genotypes. The study demonstrated the relative contribution of host- and environmental-filtering on the assemblage of the seed microbiota. It suggested some influence of these assemblages on seed germination.