Mechanisms of adaptation to climate variability in West African pearl millet landraces – a preliminary

Landraces are generally expected to possess specific mechanisms of adaptation to their growing environments. In West and Central Africa (WCA), growing conditions of pearl millet (Pennisetum glaucum) are characterized, among other hazards, by highly variable beginnings and endings of the rainy season, and unpredictable drought stress at any time during the growing season. Adaptation to such unpredictable variable environment can be due to individual and/or populational buffering (Allard and Bradshaw 1964), two mechanisms initially defined by Lerner (1954) as developmental and genetic homeostasis. Individual buffering may be favored by phenotypic plasticity. Photoperiod-sensitive flowering is an example of phenotypic plasticity that can enhance adaptation to variable planting dates followed due to a scattered beginning of the rainy season in a region, as typical for WCA. It enhances simultaneous flowering of the cultivar in the target region, independent of the individual date of planting in different fields. This has particular advantages in terms of reducing bird damage and insect pressure; prolonging vegetative development in case of early planting but accelerating development in case of late planting; therefore fitting plant development to available rainfall patterns and resulting potentially in increased yielding stability. Populational buffering can be promoted by genetic heterogeneity in plant stand as different genotypes present in the population are specifically adapted to different environmental conditions (Bradshaw 1965). An example is intra-varietal variation for flowering time, which would assure that in case of a dry spell, not all plants in the field will be affected by drought in their most sensitive flowering stage

Agroforesterie et services écosystémiques en zone tropicale

Respectueux de l’environnement et garantissant une sécurité alimentaire soutenue par la diversification des productions et des revenus qu’ils procurent, les systèmes agroforestiers apparaissent comme un modèle prometteur d’agriculture durable dans les pays du Sud les plus vulnérables aux changements globaux. Cependant, ces systèmes agroforestiers ne peuvent être optimisés qu’à condition de mieux comprendre et de mieux maîtriser les facteurs de leurs productions. L’ouvrage présente un ensemble de connaissances récentes sur les mécanismes biophysiques et socio-économiques qui sous-tendent le fonctionnement et la dynamique des systèmes agroforestiers. Il concerne, d’une part les systèmes agroforestiers à base de cultures pérennes, telles que cacaoyers et caféiers, de régions tropicales humides en Amérique du Sud, en Afrique de l’Est et du Centre, d’autre part les parcs arborés et arbustifs à base de cultures vivrières, principalement de céréales, de la région semi-aride subsaharienne d’Afrique de l’Ouest. Il synthétise les dernières avancées acquises grâce à plusieurs projets associant le Cirad, l’IRD et leurs partenaires du Sud qui ont été conduits entre 2012 et 2016 dans ces régions. L’ensemble de ces projets s’articulent autour des dynamiques des systèmes agroforestiers et des compromis entre les services de production et les autres services socio-écosystémiques que ces systèmes fournissent

Construction of a genetic map for pearl millet, Pennisetum glaucum (L.) R. Br., using a genotyping-by-sequencing (GBS) approach

Pearl millet is the main component of traditional farming systems and a staple grain in the diet of sub-Saharan Africa and India. To facilitate breeding work in this crop, a genetic map consisting of single nucleotide polymorphism (SNP) markers was constructed using an F-2 population of 93 progenies, from a wild x cultivated pearl millet cross. We used a modified genotyping-by-sequencing (GBS) protocol involving two restriction enzymes (PstI-MspI) and PCR amplification with primers including three selective bases to generate 3,321 SNPs. Of these, 2,809 high-quality SNPs exhibited a minor allele frequency >= 0.3. In total, 314 non-redundant haplotypes and 85 F-2 individuals were used to construct a genetic map spanning a total distance of 640 cM. These SNPs were evenly distributed over seven linkage groups ranging considerably in size (62-123 cM). The average density for this map was 0.51 SNP/cM, and the average interval between SNP markers was 2.1 (+/- 0.6) cM. Finally, to establish bridges between the linkage groups of this and previous maps, 19 SSR markers were examined for polymorphism between the parents of this population. We could only tentatively suggest a correspondence between four of our linkage groups and those of previous maps. Overall, GBS enabled us to quickly produce a genetic map with a density and uniformity of markers greater than previously published maps. The availability of such a map will be useful for the identification of genomic regions associated with Striga resistance and other important agronomic traits

Anomalie de développement sexuel : un cas de pseudohermaphrodisme masculin ou anomalie de développement sexuel

The feminine pseudohermaphrodism (FPH) or anomaly of the sexual development XX, rare intersexual state, represents the most frequent affection of the anomalies of the sexual development. The most frequent reason is the congenital hyperplasia of the adrenal. We return in this present work a case of feminine pseudohermaphrodism or anomaly of the sexual development XX. It was about a patient, of masculine kind, received in consultation at the age of 14 years for bilateral cryptorchidism confirmed to the clinical exam. The cytogenetic analysis indicated a normal karyotype of feminine type. The blood hormonal dosage indicated a block in 11β-OH. The analysis of this observation raises the carelessness or the ignorance of the parents facing the pathologies serious neonatal where the child's vital prognosis is not hired but to the heavy consequences for the insertion of these children in the society.Keywords : Feminine pseudohermaphrodism, anomaly of the sexual development XX, karyotype, social sexJ. Rech. Sci. Univ. Lomé (Togo), 2012, Série D14(1) : 67-7

Anomalie de développement sexuel : un cas de pseudohermaphrodisme masculin ou anomalie de développement sexuel

The anomalies of the sexual development must be detected to the birth where they constitute an emergency neonatal. What is not often the case in the African countries where they can pass unobserved to the period neonatal because of their ignorance, their ignorance or the carelessness. We return in this present work a case of masculine pseudohermaphrodism or anomaly of development sexual XY. It was about a patient, of feminine social sex, that consulted at the age of 24 years for a primary amenorrhea. The echographia exam noted an absence of internal genitalia. The karyotype was of normal masculine type 46, XY. The analysis of this observation raises the carelessness, the ignorance or the ignorance of the parents facing a sexual ambiguousness where the choice arbitrary of the social sex according to the will of the parents without gait medical pose of heavy problems for this individual's insertion in the society.Keywords: masculine pseudohermaphrodism, anomaly of sexual development XY, karyotype, social sexJ. Rech. Sci. Univ. Lomé (Togo), 2012, Série D, 14(1) : 51-5

Correlation Entre Les Differents Parametres Du Sperme A Lome (Togo) (Couleur, pH, numération et cytologie)

Introduction et objectifs : Au Togo, il n'existe pas d'études sur les relations entre les différents paramètres du sperme (Couleur, pH, numération et cytologie). L’objectif de présent travail a été de déterminer l’existence d’une éventuelle corrélation entre ces paramètres du sperme.Méthodologie : Il s’est agi d’un travail prospectif et analytique de trois mois par la réalisation du spermogramme et de spermocytogramme chez des patients reçus au laboratoire de l’Institut National d’Hygiène (INH) de Lomé (Togo) dans le cadre de l’exploration biologique de la stérilité. Les paramètres étudiés ont été : âge des patients, pH du sperme, couleur du sperme, numération des spermatozoïdes, cytologie des spermatozoïdes et le calcul des différents coefficients de corrélation.Résultats : Durant la période de l’étude, 326 spermogrammes et 161 spermocytogrammes ont été réalisés. L’âge des patients variait entre 22 et 57 ans. Le pH et la numération du sperme étaient normaux respectivement dans 94,48% et dans 33,43% des cas. La totalité des spermes avaient une proportion normale de spermatozoïdes typiques. Les différents coefficients de corrélation calculés sont tous proches de 0, donc il y a absence de corrélation entre les différents paramètres étudiés.Conclusion : Cette étude a montré qu’il n’y a pas de corrélation entre les différents paramètres du sperme. Une oligozoospermie ne serait pas liée à une variation du pH ni à une variation de la couleur du sperme. Il en est de même pour les autres anomalies de nombre des spermatozoïdes. Les formes des spermatozoïdes ne sont pas liées ni aux anomalies du pH ni à la couleur du sperme.Mots clés : Corrélation, paramètres, sperme, spermogramme, spermocytogramme.Introduction and objectives: In Togo, there exists any study on the relations between the different parameters of the semen (Color, pH, numeration and cytology). The objective of present work was to establish the existence of an interrelationship between these parameters of the semen.Methodology: It was about a prospective and analytic work of three months by the realization of spermogram and spermocytogramme among patients received to the laboratory of the National institute of hygiene (INH) of Lome (Togo) in the setting of the biologic exploration of the barrenness. The parameters studied were: age of the patients, pH of the semen, color of the semen, numeration of the spermatozoids, cytology of the spermatozoids and the calculation of the different coefficients of interrelationship.Results: During the period of the survey, 326 spermogram and 161 spermocytogram have been achieved. The age of the patients varied between 22 and 57 years. The pH and the numeration of the semen were respectively normal in 94.48% and in 33.43% of the cases. The totality of the semens had a normal proportion of typical spermatozoids. The calculated different coefficients of interrelationship are all near of 0, there is absence of interrelationship therefore between the different studied parameters.Conclusion: This survey showed that there is not an interrelationship between the different parameters of the semen. An oligozoospermia would not be bound to a variation of the pH nor a variation of the color of the semen. He/it is some in the same way for the other anomalies of number of the spermatozoids. The shapes of the spermatozoons are not nor bound to the anomalies of the pH nor to the color of the semen.Key words: Interrelationship, parameters, semen, spermogram, spermocytogram.Article in Frenc