Genetic analysis for resistance to Sitophilus zeamais (Motschulsky) among provitamin-A maize germplasm

Maize biofortification is adopted as strategy to circumvent the high risk of vitamin A deficienc, accentuated by high incidence food losses due to storage insect pests in most developing countries where maize is an important staple crop. This study was initiated to understand the mode of inheritance for resistance to storage weevils among provitamin-A germplasm. A total of 72 provitamin-A maize testcross hybrids were evaluated for agronomic and adaptive traits in three sites, Namulonge, Serere and Ngetta in Uganda during the main season of 2015. Based on genotype x environment analysis of field traits, resultant grain from two divergent environments (Namulonge and Serere) were screened for resistance against Sitophilus zeamais in a no-choice laboratory. Line by tester analysis of combining ability indicated that both additive and non-additive gene effects were important in controlling the resistance parameters, including adult mortality, F1 insects which emerged, Median Development Period, Index of Susceptibility and Grain damage. Two provitamin-A inbred lines, CLHP0014 and CLHP0005 showed high GCA effects for reduced infestation with storage weevil. Broad sense heritability was moderate (0.19 ≤ H2 ≤ 0.59) and Narrow sense heritability (h2) was low ranging from 0.19 to 0.24. The two inbred lines with desirable GCA effect for weevil resistance could be used in the development of resistant breeding population. However, the low heritability of the trait observed, suggested that effective breeding methods be deployed to increase resistance to storage weevil, concurrently with research efforts to develop high nutritional quality maize varieties

Effet de la Salinité et du Substrat sur l'Emergence et la Croissance des Propagules de l'Espèce de Mangrove Rizophora racemosa dans le Complexe Ramsar Sassandra-Dagbégo, Côte d'Ivoire

International audienceThis study aimed to evaluate the behaviour of seeded propagules of Rhirophora racemosa (R. racemosa) on different substrates and under different salinity levels. Three substrates including sand, mud and a mixture of the two were tested together with tree salinity levels (low 5%, moderate 10% and high 25%). R. racemosa seedlings were more likely to emerge and grow under moderate and low salinity conditions. The propagules had significant early growth in mud compared to sand and mud-sand mixture. The combined effect of salt and substrate influenced significantly propagules performance in nursery (p < 0.001). High propagules emergence and growth were observed in the combination mud and salt treatments as compared to sand and san-mud mixture substrates. These results provide valuable information for the management and restoration of mangroves, highlighting the optimal environmental conditions for the successful regeneration of this species.Cette étude visait à évaluer le comportement des propagules semées de Rhirophora racemosa (R. racemosa) sur différents substrats et sous différents niveaux de salinité. Trois substrats, à savoir le sable, la boue et un mélange des deux, ont été testés en conjonction avec trois niveaux de salinité (faible 5 %, modéré 10 % et élevé 25 %). Les plantules de R. racemosa étaient plus susceptibles de germer et de croître dans des conditions de salinité modérée et faible. Les propagules ont montré une croissance initiale significative dans la boue par rapport au sable et au mélange sable-boue. L'effet combiné du sel et du substrat a influencé de manière significative la performance des propagules en pépinière (p < 0,001). Une émergence et une croissance élevées des propagules ont été observées dans les traitements combinant boue et la salinité élevée, par rapport aux substrats sable et mélange sable-boue. Ces résultats fournissent des informations précieuses pour la gestion et la restauration des mangroves, mettant en évidence les conditions environnementales optimales pour la régénération réussie de cette espèce

Genetic Diversity and Association Analysis for Carotenoid Content among Sprouts of Cowpea (<i>Vigna unguiculata</i> L. Walp)

The development and promotion of biofortified foods plants are a sustainable strategy for supplying essential micronutrients for human health and nutrition. We set out to identify quantitative trait loci (QTL) associated with carotenoid content in cowpea sprouts. The contents of carotenoids, including lutein, zeaxanthin, and β-carotene in sprouts of 125 accessions were quantified via high-performance liquid chromatography. Significant variation existed in the profiles of the different carotenoids. Lutein was the most abundant (58 ± 12.8 mg/100 g), followed by zeaxanthin (14.7 ± 3.1 mg/100 g) and β-carotene (13.2 ± 2.9 mg/100 g). A strong positive correlation was observed among the carotenoid compounds (r ≥ 0.87), indicating they can be improved concurrently. The accessions were distributed into three groups, following their carotenoid profiles, with accession C044 having the highest sprout carotenoid content in a single cluster. A total of 3120 genome-wide SNPs were tested for association analysis, which revealed that carotenoid biosynthesis in cowpea sprouts is a polygenic trait controlled by genes with additive and dominance effects. Seven loci were significantly associated with the variation in carotenoid content. The evidence of variation in carotenoid content and genomic regions controlling the trait creates an avenue for breeding cowpea varieties with enhanced sprouts carotenoid content

Digital Agriculture Policies and Strategies for Innovations in the Agri-Food Systems—Cases of Five West African Countries

The digital transformation of agriculture can support economic growth and food and nutrition security in Africa. The objectives of this study were to provide an overview of the status of digital agriculture in five West African countries, analyze their efforts in developing the enabling environment and innovations, and formulate recommendations based on the identified gaps for the effective transformation of the sector. For this purpose, a literature search was performed using various sources, including web pages and databases of national agricultural and digital transformation institutions and start-ups of the five target countries (Benin, Burkina Faso, Côte d’Ivoire, Ghana, and Nigeria) and regional/international institutions. The information retrieved was used for individual country and cross-country comparative analysis of the progress and propositions of feasible actions for improvements. The results showed increasing agri-digital initiatives in the five countries, which were grouped into seven categories based on their objectives. Steady progress was also observed in mobile internet adoption, despite the differences in deploying crucial infrastructure to promote digital agriculture. The mobile connectivity index (MCI) in all five countries is below 60. Nonetheless, Ghana and Côte d’Ivoire demonstrated more efforts in internet and electricity access, especially in rural areas. Benin and Nigeria have developed separate documents depicting the roadmap for digital agriculture, while the other countries are working to create one or have it embedded in their national development plans. Similarities and specificities exist among countries for laws and processes protecting agri-digital innovators. To be competitive and self-reliant in the global e-economy, these countries must reposition themselves to accelerate changes in digital agriculture through effective governance and synergy of actions in different sectors and across nations