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Background Understanding end-users’ preferred breeding traits and plant management practices is fundamental in defining sound breeding objectives and implementing a successful plant improvement programme. Since such knowledge is lacking for Synsepalum dulcificum, a worldwide promising orphan fruit tree species, we assessed the interrelationships among socio-demography, ecology, management practices, diversity and ranking of desired breeding traits by end-users of the species (farmers, final consumers and processing companies) in West Africa. Methods Semi-structured interviews, field-visits and focus groups were combined to interview a total of 300 farmers and final consumers belonging to six sociolinguistic groups sampled from three ecological zones of Benin and Ghana. One processing company in Ghana was also involved. Data collected included socio-demographic characteristics; crop management systems and practices; and preferences of farmers, final consumers and processing companies and ranking of breeding traits. Data were analysed using descriptive statistics, independence, and non-parametric tests, generalized linear models, multi-group similarity index and Kendall’s concordance coefficient. Results Men (86.33% of respondents) were the main holders of S. dulcificum in the study area. The three most frequent management practices observed in the species included weeding, fertilization and pruning, which were applied by 75.66%, 27.33% and 16.66% of respondents, respectively. The management intensity index varied significantly across ecological zones, sociolinguistic groups, and instruction level (p < 0.001) but was not affected by gender (p > 0.05). General multigroup similarity indices ($$ {\mathrm{C}}_{\mathrm{S}}^{\mathrm{T}} $$ C S T ) for farmer-desired traits, on one hand, and final consumer-desired traits, on the other hand, were high across ecological zones ($$ {\mathrm{C}}_{\mathrm{S}}^{\mathrm{T}} $$ C S T ≥ 0.84) and sociolinguistic groups ($$ {\mathrm{C}}_{\mathrm{S}}^{\mathrm{T}} $$ C S T > 0.83). Nevertheless, respondents from the Guineo-Congolian (Benin) and the Deciduous forest (Ghana) zones expressed higher agreement in the ranking of desired breeding traits. Preference for breeding traits was 60% similar among farmers, final consumers, and processors. The key breeding traits desired by these end-users included in descending order of importance big fruit size, early fruiting, high fruit yielding (for farmers); big fruit size, high fruit miraculin content, fruit freshness (for final consumers); and high fruit miraculin content, big fruit size, high fruit edible ratio (for processing companies). Conclusion This study revealed stronger variations in current management practices across ecological zones than across sociolinguistic groups. A high similarity was shown in end-users’ preferences for breeding traits across the study area. Top key traits to consider in breeding varieties of S. dulcificum to meet various end-users’ expectations in West Africa include fruit size and fruit miraculin content. These results constitute a strong signal for a region-wide promotion of the resource.

De par sa structure, en faisant référence à la notion d’élèves « différemment doués », le système éducatif allemand procède à une sélection précoce dans la scolarité des élèves. Bien qu’on insiste en Allemagne sur l’aspect social et sur l’égalité des chances, il n’est pas politiquement possible de remettre en cause ce système scolaire fondé sur différentes filières. Beaucoup de chercheurs l’accusent de figer les disparités sociales. En outre, les disparités régionales entre les seize Länder, ...

Sensory attributes of cassava semolina (gari and eba)., Summary The purpose of this review is to support breeders and food scientists by examining research carried out on end‐user preferences for gari and its derived dough product, eba, in Africa. The review focused on gari regarding the physical and chemical composition of raw cassava roots, methods of storage, the composition of gari with or without enrichment, and the sensory evaluation of gari and eba. The primary sensory attributes identified to describe gari are colour, taste, texture, aroma and flavour. Texture attribute of importance is crispiness for uncooked gari, and hand feel before consumption for eba. There was a significant correlation between the sensory characteristics of gari and the starch and cyanogenic potential (CNP) contents of the raw roots. Hence, the correlation of the end‐user preferences with the chemical composition of the cassava roots could be helpful to breeders in refining selection criteria and developing high‐throughput screening methods.

Within communities in Osun and Imo States of Nigeria, farmer–processors grew and processed a diverse set of improved and landrace cassava varieties into the locally popular foods, gari, eba and fufu. Local and 15 main varieties were grown in a ‘mother and baby trials’ design in each state. Mother trials with three replications were processed by farmer–processors renown in their community for their processing skills. Baby trials were managed and processed by other farmer–processors. The objective was to identify food quality criteria to inform demand‐led breeding to benefit users, especially women, given their key roles in processing. Farmer–processors evaluated the overall quality of fresh roots and derived food products through pairwise comparisons. Improved varieties had higher fresh and dry root yield. Overall, landraces ranked first for quality of gari and eba, but several improved varieties were also appreciated for good quality. Landraces in Osun had higher gari yield and a higher swelling power compared to improved varieties. Colour (browning), bulk density, swelling power, solubility and water absorption capacity were the criteria most related to food product ranking by farmer–processors. Evaluation of varieties under farmer–processors’ conditions is crucial for providing guidance to breeders on critical selection criteria., Using a socially inclusive ‘mother baby trial’ approach, farmer processors in two states in Nigeria grew and processed a diverse set of cassava varieties and evaluated the root and food product quality and provided quality criteria through pairwise ranking. This evaluation was linked to fresh roots agronomic data as well as the laboratory measurements on the food product gari to inform breeding.

Designing innovative cropping systems is an active field of agricultural research challenged by the agroecological transition. One of the challenges is to adapt cropping systems to the diversity of farms and contexts. For instance, in the cotton production zone of Burkina Faso differences between farm resources, agricultural situations and agronomic constraints have resulted in a wide range of farming systems. In this context, to break with the trend toward cotton production, we co-designed eight legume-based innovative cropping systems (ICS) likely to meet the objectives sought and the constraints faced by a wide range of local farmers, thus constituting a “basket of options”. Our approach was to enable each farmer to choose the option they considered best suited to their conditions. To that end, the ICSs were implemented and discussed with farmers in participatory prototyping trials. After one season of co-evaluating the different ICSs, the farmers taking part in the co-evaluation were able to test an ICS on their own farm, by choosing and adapting one of the options. Thirty-nine farmers out of seventy-three chose an ICS to test. They were asked the reasons for their choice. Their selection criteria were analyzed in relation to comments made during collective activities organized in the participatory prototyping trials. To complete this analysis, we built an expert-based farming system typology and a statistical typology based on data collected in a rural household multi-indicator survey (RHoMIS) of 63 farms participating in this study. The two farming system typologies were compared, and the relationships between farming system types and the ICS tested on the farm were analyzed. We found that farmers did not really base their choice on their farming system. Rather, they used a wide range of criteria that varied from farmer to farmer, and they were influenced by what they had learned during the collective activities organized in the participatory prototyping trials.

Prioritizing sensory attributes and consumer evaluation early in breeding trials to screen for end-user preferred traits could improve adoption rates of released genotypes. In this study, a lexicon and protocol for descriptive sensory analysis (DSA) was established for sweetpotato and used to validate an instrumental texture method for which critical values for consumer preference were set. The study comprised several phases: lexicon development during a 4-day workshop; 3-day intensive panel training; follow-up virtual training, evaluation of 12 advanced genotypes and 101 additional samples from two trials in 2021 by DSA and instrumental texture analysis using TPA double compression; and DSA, instrumental texture analysis and consumer acceptability tests on 7 genotypes in on-farm trials. The established sweetpotato lexicon comprising 27 sensory attributes enabled characterization and differentiation of genotypes by sensory profiles. Significant correlation was found between sensory firmness by hand and mouth with TPA peak positive force (r = 0.695 and r = 0.648, respectively) and positive area (r = 0.748, r = 0.715, respectively). D20, NAROSPOT 1, NASPOT 8, and Umbrella were the most liked genotypes in on-farm trials (overall liking = 7). An average peak positive force of 3700 gf was proposed as a minimum texture value for screening sweetpotato genotypes, since it corresponded with at least 46 % of consumers perceiving sweetpotatoes as just-about-right in firmness and a minimum overall liking of 6 on average. Combining DSA with instrumental texture analysis facilitates efficient screening of genotypes in sweetpotato breeding programs.

The review aimed to identify the different High Throughput phenotyping (HTP) techniques that used for quality evaluation in cassava and yam breeding programs, and this has provided insights towards the development of metrics and their application in cassava and yam improvements. A systematic review of the published research articles involved the use of NIRS in analyzing the quality traits of cassava and yam was carried out, and Scopus, Science Direct, Web of Sciences and Google Scholar were searched. The results of the review established that NIRS could be used in understanding the chemical constituents (carbohydrate, protein, vitamins, minerals, carotenoids, moisture, starch, etc.) for high throughput phenotyping. This study provides preliminary evidence of the application of NIRS as an efficient and affordable procedure for HTP. However, the feasibility of using mid‐infrared spectroscopy (MIRS) and Hyperspectral imaging (HSI) in combination with the NIRS could be further studied for quality traits phenotyping.

Les caractéristiques de qualité des fruits sont directement liées à leur aptitude à la commercialisation et à l'acceptabilité par le consommateur, et sont donc des cibles clés pour les programmes de sélection des bananiers. La difficulté à combiner ces critères, notamment avec ceux de tolérance aux maladies et de rendement, limite actuellement l'adoption de nouveaux hybrides. Cette thèse a pour objectif d'explorer le contrôle génétique de caractères liés à la qualité du fruit, aussi bien organoleptique que fonctionnelle, au travers d'une étude d'héritabilité et une cartographie de QTL afin à terme de faciliter l'amélioration variétale des bananiers. Nous avons tout d'abord étudié la variabilité de trois traits de qualité organoleptiques majeurs : l'acidité de la pulpe (pH), sa fermeté (FEP) et sa teneur en matière sèche (TMS). Nous nous sommes ensuite intéressés à la variabilité du dégrain (DE), qui correspond à la force de rupture du pédoncule du fruit, en relation avec des critères de maturation du fruit. Ces critères ont été suivis sur une période de mûrissement de 7 jours et durant trois cycles de production dans une population en ségrégation de 162 bananiers diploïdes, issus du croisement P. Madu x Galéo. L'ensemble des caractères présente des niveaux de variabilité importants et de bons niveaux d'héritabilité, avec des valeurs de 0.77, 0.46, 0.81 et 0.64 pour le pH, la FEP, le TMS, et le DE, respectivement. La recherche de QTL par multiple-QTL mapping (MQM) a été réalisée sur deux cartes parentales, d'une part sur l'ensemble des données pour chaque jour de murissement afin d'étudier leur dynamique, et d'autre part sur les jeux de données spécifiques aux trois cycles de production afin d'évaluer leur stabilité. Des QTL majeurs (LOD ≥ 3, R² ≥ 15%) ont été détectés pour chacun de ces critères. Des QTL spécifiques d'un stade de mûrissement et d'un cycle de production ont été détectés en majorité, mais aussi de nombreuses zones de co-localisation de QTL. Pour certains critères, une méta- analyse a été effectuée pour confirmer ces co-localisations d'une part, et pour affiner les intervalles de confiance d'autre part. Les QTL les plus intéressants en lien avec l'acidité de la pulpe (R² = 19,3- 50,6%) et la FRP (R² = 16.9-18.9%) ont été détectés sur le LG1_7 de la carte génétique de Pisang Madu. Ce cultivar présente un fort taux d'apparentement à Cavendish, le groupe de cultivars de bananes dessert le plus cultivé au monde. Ces QTL sont situés sur le chromosome 1T7 qui est issu d'une translocation réciproque, qui est présent à l'état hétérozygote chez Pisang Madu et qui ne recombine pas sur une large partie, ce qui constitue un contexte favorable au suivi par marqueurs moléculaires. Les effets des QTL détectés devront être vérifiés dans différents fonds génétiques et environnements. Ces premiers résultats fournissent une base de réflexion intéressante pour l'optimisation des stratégies de création variétale, et pour envisager la sélection assistée par marqueurs dans les programmes d'amélioration des bananiers.

International audience; La domestication des animaux et leur sélection sont fondées sur une longue histoire partagée entre les hommes, les animaux et les territoires. Elle s’est nourrie par l’accumulation continue de nouvelles connaissances et approches méthodologiques qui permettent de caractériser la diversité génétique et de progresser dans le choix des reproducteurs adaptés à des systèmes de production de plus en plus diversifiés en lien avec la transition agroécologique et la sécurité alimentaire mondiale. L’amélioration génétique contribue à façonner le vivant, ce qui pose des questions éthiques dont l’acuité est renforcée par les outils de la génomique et les « big data ».

The rapid loss of fruit firmness is a qualitative decisive factor for characterizing apricot (Prunus armeniaca L.) use (fresh or processed) and commercialization pathways (short or storage). To better understand the texture variability in apricot, we studied the impact of a heat treatment as a function of fruit harvest stage on a large range of cultivars. Eighteen apricot cultivars were characterized at two maturity stages before and after cooking (85 °C in light syrup). A compression test allowed sorting the fruits to obtain homogeneous batches. Kramer shear tests provided global firmness of cooked fruits and puncture tests were performed on the median equatorial area of apricot flesh for fresh and cooked fruits. Among the registered variables, the apricot texture expressed by the “Work to limit” integrates the global evolution and allows a good discrimination of the ripening effect. The texture data was used to classify the varieties according to their firmness and suitability for industrial processing. Thus Vertige, Candide and Gaterie, followed by Orangered and Bergarouge, have been found as the most suitable cultivars for industrial processes.

De nombreuses études biologiques ont pour objectif de mesurer l'effet d'un stimulus ou d’un traitement sur les concentrations de biomarqueurs dans les tissus biologiques. Pour ce faire, il faut sélectionner la méthode d'analyse la mieux adaptée, capable de détecter une différence entre les concentrations avant et après traitement. Nous avons récemment publié une approche pour effectuer cette sélection. Elle s’appuie sur un critère appelé « seuil de discrimination » (SD). La présente publication explique son application à une méthode analytique HPLC, développée pour déterminer les teneurs plasmatiques en adrénaline et en noradrénaline des bovins, dans le cadre d’une étude de détection du stress. Pratiquement, le SD est dérivé de l'incertitude de mesure (IM) et combine la variabilité de la méthode analytique et le niveau de réponse du biomarqueur. L'incertitude de mesure est facile à obtenir quand on connait la fonction d’incertitude de la méthode qui s’obtient à l’issue de l’étude de validation. Les niveaux de réponse des marqueurs (ici l’adrénaline et la noradrénaline) sont modélisés à partir d'une étude bibliographique. La méthode d'analyse proposée s'avère adaptée lorsque la variation des taux plasmatiques dépasse 2 ng.ml-1 pour l’adrénaline et 2.5 ng.ml-1 pour la noradrénaline.

Description du sujet. Les ligneux fourragers constituent une source importante pour la survie des ruminants en période de soudure. Vu la pression qu’ils subissent et par conséquent leur rareté dans les terres de parcours, une étude a été conduite dans la zone de transition soudano-guinéenne du Bénin auprès des populations riveraines des forêts classées des Monts Kouffé, de Wari-Maro et de l’Ouémé supérieur.Objectifs. L’étude vise à identifier les ligneux fourragers prioritaires pour le pastoralisme, analyser l’utilisation et les intensités de coupe des ligneux fourragers en relation avec les différents groupes sociolinguistiques de la zone d’étude et évaluer leur priorité pour la conservation. Méthode. Les données de la littérature ont permis de compléter celles issues des enquêtes afin de constituer une base de données sur différents critères définis. Les taux de citation des espèces par les populations ont permis d’établir leur priorité pour le pastoralisme, alors que la priorisation des ligneux pour la conservation est réalisée avec une combinaison de quatre méthodes et neuf critères.Résultats. Les résultats montrent que 48 espèces sont utilisées comme fourrage aérien et réparties en 17 familles dominées par les Leguminosae (27,1 %) et les Moraceae (16,6 %), et 37 genres dont le plus représenté est le genre Ficus (16,6 %). L’appétibilité, la disponibilité des espèces et leur productivité (au niveau des animaux) sont les critères de choix des ligneux fourragers par les différents groupes sociolinguistiques. Afzelia africana, Pterocarpus erinaceus, Khaya senegalensis, Vitellaria paradoxa, Mangifera indica, Ficus platyphylla, Balanites aegyptiaca, Annona senegalensis, Ficus umbellata et Daniellia oliveri sont les dix premiers ligneux fourragers prioritaires identifiés pour la conservation dont la plupart se trouvent prioritaires pour le pastoralisme.Conclusions. Pour une exploitation rationnelle des ligneux fourragers, nous suggérons l’utilisation des espèces prioritaires aussi bien pour le pastoralisme que pour la conservation dans les plans d’aménagement des parcours naturels au cours des activités d’afforestation/reforestation et de reboisement., Diversity, pastoral and conservation priorities of fodder trees in the Sudano-Guinean pasture lands of Benin Description of the subject. Fodder trees are important for livestock survival in dryland Africa. In view of the pressure faced by these trees, and their consequent rarity noted in rangelands, a study was conducted in the Sudano-Guinean transition zone of Benin at the level of the local population surrounding the protected forests of Monts Kouffé, Wari-Maro and Ouémé Supérieur.Objectives. This study aimed to inventory the fodder trees, analyze the local perception of factors threatening target fodder trees, according to different sociolinguistic groups and prioritize fodder trees for conservation. Method. Ethnobiological surveys and ecological data from the available literature were used to construct a database following different criteria. The citation rates of the fodder trees by the surveyed populations were used to establish pastoral priority, while their conservation priority was established using a combination of four methods and nine criteria.Results. Forty-eight fodder trees belonging to 17 families dominated by Leguminosae (27.1%) and Moraceae (16.6%) were reported. These species were distributed among 37 genera, with the genus Ficus being the most represented (16.6%). Palatability, species availability and the impact of tree fodder on animal productivity were the criteria used by the surveyed sociolinguistic groups in their selection of fodder trees. The prioritization methods yielded ten top ranked species: Afzelia africana, Pterocarpus erinaceus, Khaya senegalensis, Vitellaria paradoxa, Mangifera indica, Ficus platyphylla, Balanites aegyptiaca, Annona senegalensis, Ficus umbellata and Daniellia oliveri. Conclusions. With the aim of establishing the sustainable management of pasture lands, we suggest that priority be given to the aforementioned species of fodder trees as part of restoration, afforestation/reforestation and plantation activities.

Viral encephalopathy and retinopathy (VER), otherwise known as viral nervous necrosis (VNN), is a major devastating threat for aquatic animals. Betanodaviruses have been isolated in at least 70 aquatic animal species in marine and in freshwater environments throughout the world, with the notable exception of South America. In this review, the main features of betanodavirus, including its diversity, its distribution and its transmission modes in fish, are firstly presented. Then, the existing diagnosis and detection methods, as well as the different control procedures of this disease, are reviewed. Finally, the potential of selective breeding, including both conventional and genomic selection, as an opportunity to obtain resistant commercial populations, is examined.

International audience

SUMMARYSorghum (Sorghum bicolor(L.) Moench) is a major staple crop of Burkina Faso where farmers continue to cultivate photoperiod-sensitive guinea landraces as part of the strategy to minimize risk and ensure yield stability. In the Boucle du Mouhoun region, however, sorghum farmers appear to have insufficient varietal choice due to cropping systems having shifted towards more intensive cultivation of cotton and maize, and rainfall patterns having decreased over the past decade. In search for new varietal options that can respond to this changing context, researchers decided to give farmers access to ex-situ national collections along with the opportunity to evaluate recent improved varieties. From 2002 to 2007, researchers and farmers worked closely together to implement on-farm testing, including varietal selection trials, crop management and multi-locational trials. Farmers’ choices tend to differ among groups, villages and years, with the exception of four particular landraces: two originating from a collection carried out in the Mouhoun region more than 30 years previous to this research, and two other landraces that came from the dissimilar agro-ecological zones of Burkina Faso. These four were the most commonly selected landraces out of 36 cultivars that covered both improved and landrace varieties. Farmers’ selection criteria were focused on adaptation to agro-climatic conditions as well as specific grain qualities for processing and consumption. The potential usefulness of each variety was verified via multi-locational trials. The paper also shows that wide dissemination of experimental seed, not just across the Mouhoun region but also at a national scale, was largely achieved through collaboration with a strong farmer organisation in conjunction with farmer training programs focused on the on-farm seed production and the commercialisation of this seed.

UMR AGAP - équipe AFEF - Architecture et fonctionnement des espèces fruitières; Breeding in apple is characterized by a high number of characters concerned, related to several biological processes. The main characters are fruit quality, disease resistance and yield. In addition, the will to reduce the use of chemical products in agriculture and the changing climatic context causes the need to breed for new complex characters such as yield regularity and adaptation to temperature increase. This work is a study case of trait integration for fruit quality, yield level and regularity, and bud phenology related traits. Compatibility of breeding objectives, according to one fixed ideotype, were analysed and a strategy for the introduction of new characters in breeding schemes using molecular markers, breeding values estimation, and selection indexes was proposed. Two unrelated families were phenotyped, QTL analyses were run with the Bayesian software FlexQTLTM and the individual genetic breeding values were computed trait by trait by adding the genetic effect of loci estimated during the QTL mapping process. An ideotype integrating all traits was fixed and principal component analyses were realized in order to study the breeding goals compatibility. Traits were integrated in two selection indexes computed with breeding values. Synergistic correlations between fruit size and yield regularity was identified and antagonistic correlation was observed between fruit size and yield level, and yield regularity and level and partially explained by colocalization of QTLs with high opposite effects according to the ideotype. In case of antagonistic correlation between important traits, a genetic ideotype could be a tool to monitor precisely the choice of genitors and identification of progenies compatible with the ideotype. Principal component analyses and selection indexes values revealed a differential genetic potential of the two families depending on traits and their correlations, and interesting individuals could be identified in both families even if selection indexes values were in favor of one of the families. In conclusion, the use of molecular markers, genetic effects estimation in a genomic selection approach, combined with a selection index strategy would be an efficient way to introduce simultaneously new complex characters in breeding schemes.

National audience; Après avoir défini le pré-breeding, son rôle et son positionnement dans les schémas de sélection,une analyse de l'organisation du partenariat public-privé est présentée en s'appuyant sur des exemples.L'impact des marqueurs moléculaires sur l'efficience du transfert de caractères innovants dans despools élites est également souligné par des exemples. Des éléments d'évolution du contexte de mise enoeuvre du pré-breeding sont déclinés. Des interrogations sont formulées quant à l'évolution de larépartition des missions entre la recherche publique et la recherche/sélection privée, les moyensd'assurer le transfert, la valorisation des connaissances produites par la recherche publique, et le rôlede celle-ci concernant les espèces mineures, voire orphelines de recherche.

National audience; Co-clustering aims to identify block patterns in a data table, from a joint clustering of rows and columns. This problem has been studied since 1965, with recent interests in various fields, ranging from graph analysis, machine learning, data mining and genomics. Several variants have been proposed with diverse names: bi-clustering, block clustering, cross-clustering, or simultaneous clustering. We propose here a review of these methods in order to describe, compare and discuss the different possibilities to realize a co-clustering following the user aim.; La classification croisée vise à identifier une structure sous-jacente existant entre les lignes et colonnes d'un tableau de données. Cette revue bibliographique présente les différents points de vue abordés depuis cinquante ans pour définir cette structure et propose pour chacun un éventail non exhaustif des algorithmes et applications associés. Enfin, les questions encore ouvertes sont abordées et une méthodologie est proposée dans la partie discussion pour analyser des données réelles.

National audience; Co-clustering aims to identify block patterns in a data table, from a joint clustering of rows and columns. This problem has been studied since 1965, with recent interests in various fields, ranging from graph analysis, machine learning, data mining and genomics. Several variants have been proposed with diverse names: bi-clustering, block clustering, cross-clustering, or simultaneous clustering. We propose here a review of these methods in order to describe, compare and discuss the different possibilities to realize a co-clustering following the user aim.; La classification croisée vise à identifier une structure sous-jacente existant entre les lignes et colonnes d'un tableau de données. Cette revue bibliographique présente les différents points de vue abordés depuis cinquante ans pour définir cette structure et propose pour chacun un éventail non exhaustif des algorithmes et applications associés. Enfin, les questions encore ouvertes sont abordées et une méthodologie est proposée dans la partie discussion pour analyser des données réelles.

The aim of this paper was to understand the process of selecting soybean ( Glycine max [L.] Merr.) promiscuous varieties by smallholders for soil fertility management in western Kenya. Eight varieties were screened on 2.5 m × 3 m plots that were managed according to farmers’ practices and evaluated through participatory monitoring and evaluation approaches. Farmers selected preferred varieties and explained their reasons (criteria) for making the selections. Seven promiscuous varieties had better yields than a local one. Farmers’ selection criteria fell into three broad categories relating to yield, appearance and labour. Selection criteria were not primarily aimed to improve soil fertility. This created a challenge to embed the new varieties within the local farming systems for soil fertility improvement. This study shows that farmer criteria for selecting varieties overlapped with scientific procedures. We propose co-research activities targeted to strengthen farmer experimentation skills, their understanding on N addition, and the role of P.

Cette contribution interroge les effets discriminants de l’orthographe, au cours d’un processus de recrutement en entreprise, à travers la réaction engendrée par la lecture des documents de candidature. Un dispositif expérimental en milieu naturel est mis en œuvre pour comparer les prises de contact initiées par les recruteurs suite à la réception de deux candidatures à une offre d’emploi : l’une à l’orthographe impeccable, l’autre à l’orthographe lacunaire. L’auteur démontre que la norme graphique agit en tant que critère de sélection à l’embauche. This paper questions the discriminatory effect of spelling during a recruitment process through the reaction generated by reading the application documents. An experimental device in natural environment is implemented to compare contacts initiated by recruiters after receiving two applications for a job : one with perfect spelling, the other with faulty spelling. The author demonstrates that the spelling standards act as a selection criterion for hiring.

Groundnut ( Arachis hypogaea L.) is the most important oil and cash crop in the sub-Sahelian tropics. Plant adaptation to drought, i.e. cultivars (cvs) that can maintain yield when water is limited, is a complex phenomenon which is not yet fully understood. This study aimed to identify traits expressed at the early stages of the cycle that could reveal cv differences in drought adaptation in the field. The field productivity of four Sahelian groundnut cvs was assessed during three crop seasons in Bambey (Senegal). The same cvs grown in rhizotrons were subjected to early drought stress and to a desiccation test to assess cell membrane tolerance. Between-cv differences were found with respect to pod yield, biomass production, water use efficiency (WUE), stomatal regulation and cell membrane tolerance. Two strategies to cope with water deficit were identified. The first behaviour was characterised by high rapid water loss, late stomatal closure and low cell membrane damage during drought. These traits are all found in the semi-late Virginia cv 57-422 and, into a lesser extent, in the early Spanish cv Fleur 11. For both cvs, biomass production was boosted under favourable conditions in rhizotrons but the semi-late cv had poor pod yield under end-of-season water deficit conditions. The second strategy involved opposite characters, leading to the maintenance of a higher water status, resulting in lower photosynthesis and yield. This characterised the early Spanish cv 73-30, and also, to some extent, the early Spanish cv 55-437. Earliness associated with high WUE, stomatal conductance and cell membrane tolerance, were the main traits of Fleur 11, a cv derived from a Virginia × Spanish cross, which was able to maintain acceptable yield under varying drought patterns in the field. These traits, as they were detectable at an early stage, could therefore be efficiently integrated in groundnut breeding programmes for drought adaptation.

Rubber has been grown for several decades in Africa, notably in Ivory Coast. Although the yields obtained with selected clones are good, some problems with adaptation to edaphic and climatic conditions have yet to be solved. Of these problems, tree breakage due to violent winds during frequent storms is a major handicap. Some clones are more resistant to wind damage. However, this resistance trait remains difficult to measure, and detecting it at an early stage appeared important. As no differences have been found in the physical properties of the wood of different clones, the search for differences between clones displaying resistance and susceptibility to wind damage was switched to architectural structures. Architectural traits were thus studied on two rubber clones with very different resistances to wind. Observations were focused both on young trees and adult trees. Of all the architectural traits observed, a description of branching provided information likely to explain differences in the way the clones being studied developed over time. The clone GT1 which is resistant to wind, developed more lateral branches but they did not grow much in length. On the other hand, fewer axillary branches appeared on the susceptible clone PB235 but they grew longer. Moreover, as some of these traits proved to be similar in both young and adult trees, they could be detected at a sufficiently early stage for use as early prediction traits, if their involvement in susceptibility to wind damage is confirmed.

Some continuous quantitative traits such as yield are not always normally distributed. This article proposes an underlying normal distribution - called the equivalent normal distribution - to help analyze and interpret the distribution of such data. The mean and standard deviation of this distribution are estimated through the regression of the theoretical (assuming normality) selection intensity on the corresponding observed standardized selection differential at each selection rate that may be applied (as many selection rates as individuals in the distribution). This simple and pragmatic transformation does not require scale transformations, which sometimes obscure biological interpretation. A possible biological interpretation of the Equivalent Normal Distribution is presented; it considers the difference between the potential and the eventually observed performance. This method allows comparisons between distributions of apparently different shapes. Simulations furthermore indicated that Equivalent statistics, compared with observed statistics, allowed an improved prediction of genetic values and estimation of realised heritability.

Osmotic adjustment is one of several characters putatively associated with drought tolerance in rice. Indica cultivars are known to have a greater capacity for osmotic adjustment than japonica cultivars. We developed an advanced back-cross population using an indica donor, IR62266-42-6-2, to introgress osmotic adjustment into an elite japonica cultivar, IR60080-46A. One hundred and fifty BC(3)F(3) families were genotyped using microsatellites and RFLP markers, and a few candidate genes. We evaluated osmotic adjustment in these lines under greenhouse conditions using the re-hydration technique. Using the composite interval mapping technique, we detected 14 QTLs located on chromosomes 1, 2, 3, 4, 5, 7, 8 and 10 that together explained 58% of the phenotypic variability. Most, but not all, of the alleles with positive effects came from the donor parent. On chromosome 8, two QTLs were associated in repulsion. The QTL locations were in good agreement with previous studies on this trait on rice and in other cereals. Some BC(3)F(3) lines carried the favorable alleles at the two markers flanking up to four QTLs. Intercrossing these lines followed by marker-aided selection in their progenies will be necessary to recover lines with levels of osmotic adjustment equal to the donor parent. The advanced back-cross strategy appeared to be an appropriate method to accelerate the process of introgressing interesting traits into elite material.

National audience; L'objectif des auteurs est d'illustrer l'usage des mathématiques au travers d'outils utilisés dans la biologie. L'exemple de la chèvre créole est motivé notamment par l'importance de cette espèce dans le développement économique de la Guadeloupe.

Développer des variétés à la fois plus productives et bien adaptées aux conditions pédoclimatiques et aux usages locaux est un objectif majeur de l'amélioration du sorgho en Afrique de l'Ouest. Dans les régions au sud du Mali, les agriculteurs peuvent choisir aujourd'hui parmi une dizaine de variétés vulgarisées, alors qu'une seule variété améliorée est diffusée à grande échelle dans la zone sahélienne. Un programme de création variétale décentralisé et participatif du sorgho a été initié en 2011 dans deux villages de cette zone dans le cadre d'un partenariat multi-institutionnel recherche organisations paysannes-ONGs. Le programme vise à développer des variétés-lignées et des variétés populations adaptées aux contraintes agronomiques locales et aux besoins des producteurs. Pour cela, il propose plusieurs innovations comme de (i) créer des variétés dans un contexte de fortes contraintes agroclimatiques ; (ii) effectuer la sélection avec des producteurs- clés et leurs familles durant plusieurs années consécutives ; et (iii) appliquer deux méthodes de sélection, massale et généalogique, pour comparer leur efficacité. Un premier bilan de ce programme montre que les pressions de sélection exercées par les producteurs sont similaires ou moins élevées que celles habituellement appliquées en sélection généalogique conventionnelle. L'analyse préliminaire du progrès génétique obtenu indique qu'au moins un quart des lignées et populations issues de ce programme sont supérieures à la moyenne de l'essai pour deux caractères de sélection clés, le rendement et la préférence des producteurs. Cette analyse soulève de nouvelles questions, notamment sur le choix des dispositifs expérimentaux permettant d'évaluer le plus précocement possible la stabilité de rendement, et le besoin de développer des index de sélection multi-critères.

Les semences de palmiers à huile commercialisées par les obtenteurs ont pour objectif de mettre à la disposition des utilisateurs du matériel végétal performant et de qualité. Eux seuls permettent d'éviter de cruelles désillusions aux planteurs. Du fait de caractéristiques biologiques et génétiques particulières, ils savent s'affranchir des problèmes liés à l'hérédité de l'épaisseur de la coque, à la dépression de consanguinité, et faire profiter de l'hétérosis à leur création variétale, de proposer des semences tolérantes à des maladies...Par rapport à des "graines tout venant", les semences commercialisées produisent 2,5 fois plus, uniquement à cause de la prise en compte de l'hérédité de la coque et de la dépression de consanguinité. De plus, les obtenteurs ont régulièrement augmenté la productivité de leurs matériels. En 40 ans, dans les conditions de Côte d'Ivoire, le rendement est passé de 2 à 3,6 tonnes d'huile par hectare et par an. Par ailleurs, face à des maladies (Fusariose, Ganoderma ... ) qui détruisent des plantations à hauteur de 50%, les obtenteurs tentent de trouver des solutions. Ainsi, pour la fusariose en Afrique, l'impact de la maladie a été fortement réduit (à 1%). Enfin, des critères de réduction de la croissance en hauteur permettent de faciliter la récolte ou la décision de replantation. Seules les semences commercialisées par des obtenteurs permettent de sécuriser l'investissement initial dans la création ou le renouvellement d'une plantation de palmier à huile.

Reciprocal recurrent selection (RRS) has been adopted for oil palm breeding in Indonesia. Due to a long selection cycle and the large area required, a satisfactory oil palm progeny trial is difficult to conduct. Knowledge of the parental genetic parameters is very important in achieving the expected genetic progress, but the evaluation of these parameters is constrained by highly unbalanced data sets. In this study, the unbalanced agronomic data sets and the pedigree information of an oil palm breeding programme in Indonesia were analysed by using the restricted maximum likelihood (REML) and the best linear unbiased predictor (BLUP) methods. The characters analysed were bunch and oil yields of the adult period (from 7 to 9 years after planting). The coefficients of parentage varied from 0.125 to 0.891 and from zero to 0.750 between parents in the Deli and African groups, respectively. The average coefficients of inbreeding were 0.269 and 0.166 for the parents within the Deli and African groups, respectively. The additive variances of the bunch number, industrial oil-extraction rate and oil yield characters were higher in the parents of the Deli group than those in the African ones. The coefficients of correlation between the predicted and observed hybrids performances varied from 0.55 to 0.64 for oil yield, 0.49 to 0.71 for bunch number, 0.47 to 0.58 for bunch production, 0.48 to 0.64 for industrial oil-extraction rate and 0.42 to 0.56 for plant-height increment. For selection on the basis of oil yield character, BLUPs ability to predict single-cross performance should be sufficient, and will result in a significant contribution to the oil palm seed and clone productions.

Rice breeding for weed competitiveness requires improved screening tools. An ongoing breeding program uses #O. glaberrima# as genetic donor for growth vigor and weed competitiveness. This study investigates morphophysiological characteristics relevant to seedling vigor, namely, the kinetics of reserve mobilization, dry matter partitioning among organs, and specific leaf area (SLA). Five diverse cultivars (#O. glaberrima" upland rice, improved and traditional tropical #O. sativa# japonica upland rices, an improved #O. sativa# indica cultivar and an interspecific progeny) were grown in the screenhouse for 18 days on wet soil. Dry matter fractions of plant organs were measured daily, leaf area (LA) and SLA were measured 9, 14 and 18 days after seed soaking (DAS). SLA measurements were repeated using crowded populations simulating farmers' seedbed nurseries. Seedlings achieved photo-autotrophic growth between 7.6 and 9.3 DAS, and had compensated for respiration losses during heterotrophic growth at 10.3-12.4 DAS, with #O. glaberrima# and improved indica cultivars requiring shorter periods than tropical japonica cultivars. For all cultivars, dry matter partitioning coefficients (PC) for roots were initially large but dropped temporarily to near zero during the transition from heterotrophic to autotrophic growth. The #O. glaberrima# cultivar had the largest PC for laminae and the largest SLA among the cultivars. It is concluded that the superior early growth vigor of the #O. glaberrima# cultivar, as documented in previous studies, is partly due to (1) early onset of autotrophic growth, (2) high PC for leaves, and (3) large SLA. Based on the previous observation that SLA is correlated with weed competitiveness, it appears that SLA measured at about 14 days after germination might be employed as a rapid screen for weed competitiveness.