3 resultados para Diversité phylogénétique

em Bioline International


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Sorghum ( Sorghum bicolor L. Moench) is an economic and staple crop in sub-Saharan Africa. The genetic diversity in its germplasm is an invaluable aid for its crop improvement. The objective of this study was to assess the existing genetic diversity among sorghum landraces in the southwestern highlands of Uganda. A total of 47 sorghum landraces, collected from southwestern highlands of Uganda, were characterised using 12 qualitative and 13 quantitative traits. The study was conducted at Kachwekano Research Farm in Kabale District, at an altitude of 2,223 m above sea level, during growing season of December 2014 to August 2015. Panicle shape and compactness were the most varied qualitative traits. Grain yield (1.23 to 11.31 t ha-1) and plant height (144.7 to 351.6 cm) were among quantitative traits that showed high variability. Days to 50% flowering (115 to 130 days) showed the least variability. Results of UPGMA cluster analysis generated a dendrogram with three clusters. Panicle weight, leaf width, stem girth, exertion length, peduncle length, panicle shape and compactness, glume colour and threshability were major traits responsible for the observed clustering (P<0.001). Principal Component Analysis revealed the largest variation contributors.

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The eggplant ( Solanum aethiopicum ) is the species of the Solanum genus, whose geographical distribution is broadest. It is grown throughout tropical Africa, and includes three groups of cultivars commonly called African or indigenous eggplant. Kumba group or “bitter eggplant” is an important Solanaceous vegetable crop in Burkina Faso. The objective of this study was to determine genetic variability, strength of association and level of heritability among agronomic interest traits. Phenotypic and genotypic variations and heritability of 14 traits were estimated in 61 accessions at Institut de Développement Rural (IDR), Gampela in Burkina Faso. High phenotypic and genotypic coefficients of variation were observed for fruit diameter, number of seeds per fruit, fruit weight, leaf blade length and width, and height at flowering. In addition, genetic and phenotypic variances were high for the number of seed, fruit weight, plant height at flowering and days to 50% flowering. High heritability estimates were recorded for all traits. Fruit weight showed a positive association with fruit diameter and thickness. The fifty percent flowering cycle registered positive correlations with plant height and fruit diameter. Fruit number showed a negative association with fruit weight and diameter, and 50% flowering cyle.

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Les enjeux de développement en rapport avec la santé urbaine des enfants en Afrique sub-saharienne deviennent d’autant plus importants qu’on a eu à observer dans certaines villes un paradoxe sanitaire se traduisant par une mortalité relativement plus élevée que celle du milieu rural. En outre, concilier la croissance rapide des villes africaines avec l’objectif d’un environnement sanitaire adéquat et adapté à l’ampleur et à la diversité des besoins relève du défi. Cet article propose un état des lieux critique de la littérature sur la santé urbaine, à travers une synthèse de 82 travaux scientifiques portant sur les relations entre dynamiques urbaines et sanitaires. L’étude accorde un regard particulier à la santé des enfants en Afrique subsaharienne francophone. Cette synthèse met en évidence les points de convergences et de divergences de santé urbaine, et aborde aussi, sous un angle critique, les aspects méthodologiques. Elle met en évidence une pluralité de situations sanitaires urbaines, ainsi que la complexité des mécanismes explicatifs des relations entre dynamique urbaine et santé des populations.