Perceptions de la variabilité climati que et stratégies d’adaptation dans le système oasien de Gouré (Sud-est Niger)

Les savoirs liés au temps et à l’espace, et l’identification des stratégies paysannes pour affronter les problèmes climatiques sont indispensables pour toute compréhension des questions climatiques. Pour mieux apprécier les perceptions de la variabilité climatique et les stratégies d’adaptation utilisées, une enquête semi structuré qui a concerné 60 personnes repartie dans 4 villages du département de Gouré, situé dans l’Est du Niger est conduite selon une approche qualitative et quantitative. Les effets de la variabilité climatique ressentis par les agriculteurs sont l’aridité du climat, l’augmentation de la température et le caractère aléatoire des pluies. Les éleveurs la perçoivent de façon indirecte à travers la réduction du fourrage et de la disponibilité d’eau. Ces effets ont poussé ces populations à adopter des stratégies d’adaptation comme la recherche de nouvelles variétés à cycle court et supportant les poches de sécheresse, la pratique des techniques de fixation des dunes pour la restauration du couvert herbacé, l’utilisation de la fumure organique, la modification des dates de semis, le stockage de fourrage, le déstockage des animaux pendant la soudure, les prières collectives de demande de pluies. Elles sont toutefois insuffisantes du fait de la persistance des effets négatifs de la variabilité climatiques au Niger.Mots clés: Variabilité climatique, perception, stratégies d’adaptation, Gouré, NigerEnglish Title: Farmers perception and adaptation strategies to climate change in the oasis system of Goure (Southeast Niger)English AbstractKnowledge related to the perception of time and space, and identification of farmers’ strategies for dealing with climate change is a perequisite for a good understanding of climate issues. Farmers’ climate variability perceptions and adaptation strategies was studied using a survey conducted with sixty (60) farmers in the department of Gouré, located in eastern Niger. Results showed that farmers directly experience changes in  climate variability through temperature increase, frequent drought and erratic rainfall. By contrast, herders sense the effects of climate change indirectly through fodder reduction and scarce water availability. These effects have prompted farmers to adopt coping strategies such as the use of improved varieties, early and drought tolerant, sand dune stabilization and land reclamation, use of organic manure, changing of planting dates, storage of fodder, the destocking of animals during drought periods, collective prayers for rain. These strategies, however, appear to be insufficient for addressing the negative effects of climate change in this part of Niger.Keywords: climate variability, perception, strategies of adaptation, Goure, Nige

Composition en Acides Aminés des Graines de Boscia Senegalensis Issues de Différentes Méthodes de Traitements Traditionnelles au Niger

Au Niger, lors des crises alimentaires, les graines de Boscia senegalensis, appelé anza en langue local, constituent un des principaux aliments de cueillette de subsistance pour les ménages ruraux. L’objectif de la présente étude était de déterminer la composition en acides aminés des graines de Boscia issues de différentes méthodes de désamérisation. La teneur en protéinestotaux et en 16 acides aminés, dont les 8 acides aminés essentiels, des graines non cuites et cuites ont été déterminées. Le résultat obtenu montre que la teneur en protéines varie de 16,11 à 22,82%. Les acides aminés majeurs sont l’acide glutamique (2,32-3,33 %), acide aspartique (1,71-2,36 %) et la phénylalanine (1,34-2,19 %) tandis que la méthionine, l’histidine, la thréonine et la tyrosine sont les acides aminés limitant dans toutes les graines. Des faibles teneurs sont aussi trouvées pour la lysine (0-1,31 %). L’acide aminé essentiel majeur est la phénylalanine. Les essentiels mineurs sont la méthionine et la thréonine. De façon générale, les méthodes de traitements traditionnelles influencent positivement la teneur en protéines et en certains acides aminés essentiels des graines de Boscia senegalensis. In Niger, during food crises, Boscia senegalensis seeds, called Anza in the local language, are one of the main subsistence food crops for rural households. The objective of this study was to determine the amino acid composition of Boscia seeds from different deamerization methods. The protein and 16 amino acid content, including all 8 essential amino acids, of uncooked and cooked seeds were determined according to standard methods. The result obtained shows that the protein content varies from 16.11 to 22.82%. The major amino acids are glutamic acid (2.32-3.33%), aspartic acid (1.71-2.36%) and phenylalanine (1.34-2.19%) while methionine, histidine, threonine and tyrosine are the limiting amino acids in all seeds. Low levels are also found for lysine (0-1.31%). The major essential amino acid is phenylalanine and the minor essential amino acids are methionine and threonine (1.34-2.19%). In general, traditional processing methods positively influence the content of proteins and certain essential amino acids in Boscia senegalensis seeds

Agronomic characterization of eighteen cucurbitaceae cultivars used for food in Niger.

Objective: Agronomic potentialities of 18 cucurbitaceous cultivars from two species were assessed in a period of two years on the experimental field of the University Of Niamey Faculty Of Sciences. The experiment was a complete random block. Seventeen (17) cultivars of the Lagenaria siceraria species of which only one species from the Citrullus colocynthis.Methodology and results: Thirteen (13) characteristics were studied. Variance analyses showed that there was very significant difference ( p= 0.05) between cultivars for all studied characteristics, except the duration of the emergence, the date of fructification, the width of the fruit and the weight of the seed the first year. In this way, short-cycle and long cycle cultivars, as well as productive and less productive cultivars are identified. Correlations between the different characteristics showed that the yield in berries is very positively correlated to the weight of a berry (r = 0.76) and the number of seeds per berry (r = 0.61) and negatively with the width (r = - 0.66) and the length (r = -0.73) of a seed. The average production in berries is 17 per plant in the first year against 6 the second year. Better productivity is achieved with Citrullus colocynthis, which gave 82 berries per plant the 1st year. The average yield in seeds was 180.15 kg / ha in the first year and 704.30 kg / ha, in the second year.Conclusion and application of results: Niger cucurbitaceous are unknown and the results of this study show that they have a lot of potentiality and can contribute to achieve the Millennium Development Goals, especially in its food security and fight against poverty programs, since they represent an important source of income for the population.Key words: cucurbitaceous, Citrullus colocynthis, Lagenaria siceraria, agronomic characteristics, Niger

Farmers perception and adaptation strategies to climate change in the oasis system of Goure (Southeast Niger)

Les savoirs liés au temps et à l’espace, et l’identification des stratégies paysannes pour affronter les problèmes climatiques sont indispensables pour toute compréhension des questions climatiques. Pour mieux apprécier les perceptions de la variabilité climatique et les stratégies d’adaptation utilisées, une enquête semi structurée qui a concerné 60 personnes réparties dans 4 villages du département de Gouré, situé dans l’Est du Niger, est conduite selon une approche qualitative et quantitative. Les effets de la variabilité climatique ressentis par les agriculteurs sont l’aridité du climat, l’augmentation de la température et le caractère aléatoire des pluies. Les éleveurs la perçoivent de façon indirecte à travers la réduction du fourrage et de la disponibilité d’eau. Ces effets ont poussé ces populations à adopter des stratégies d’adaptation comme la recherche de nouvelles variétés à cycle court et supportant les poches de sécheresse, la pratique des techniques de fixation des dunes pour la restauration du couvert herbacé, l’utilisation de la fumure organique, la modification des dates de semis, le stockage de fourrage, le déstockage des animaux pendant la soudure, les prières collectives de demande de pluies. Elles sont toutefois insuffisantes du fait de la persistance des effets négatifs de la variabilité climatique au Niger.Knowledge related to the perception of time and space, and identification of farmers’ strategies for dealing with climate change is a perequisite for a good understanding of climate issues. Farmers’ climate variability perceptions and adaptation strategies was studied using a survey conducted with sixty (60) farmers in the department of Gouré, located in eastern Niger. Results showed that farmers directly experience changes in climate variability through temperature increase, frequent drought and erratic rainfall. By contrast, herders sense the effects of climate change indirectly through fodder reduction and scarce water availability. These effects have prompted farmers to adopt coping strategies such as the use of improved varieties, early and drought tolerant, sand dune stabilization and land reclamation, use of organic manure, changing of planting dates, storage of fodder, the destocking of animals during drought periods, collective prayers for rain. These strategies, however, appear to be insufficient for addressing the negative effects of climate change in this part of Niger

Association mapping, patterns of linkage disequilibrium and selection in the vicinity of the phytochrome C gene in pearl millet

Key message Linkage analysis confirmed the association in the region of PHYC in pearl millet. The comparison of genes found in this region suggests that PHYC is the best candidate. Major efforts are currently underway to dissect the phenotype-genotype relationship in plants and animals using existing populations. This method exploits historical recombinations accumulated in these populations. However, linkage disequilibrium sometimes extends over a relatively long distance, particularly in genomic regions containing polymorphisms that have been targets for selection. In this case, many genes in the region could be statistically associated with the trait shaped by the selected polymorphism. Statistical analyses could help in identifying the best candidate genes into such a region where an association is found. In a previous study, we proposed that a fragment of the PHYTOCHROME C gene (PHYC) is associated with flowering time and morphological variations in pearl millet. In the present study, we first performed linkage analyses using three pearl millet F-2 families to confirm the presence of a QTL in the vicinity of PHYC. We then analyzed a wider genomic region of similar to 100 kb around PHYC to pinpoint the gene that best explains the association with the trait in this region. A panel of 90 pearl millet inbred lines was used to assess the association. We used a Markov chain Monte Carlo approach to compare 75 markers distributed along this 100-kb region. We found the best candidate markers on the PHYC gene. Signatures of selection in this region were assessed in an independent data set and pointed to the same gene. These results foster confidence in the likely role of PHYC in phenotypic variation and encourage the development of functional studies