DIVERSITE MORPHOLOGIQUE DES VARIETES LOCALES DE MAÏS (ZEA MAYS L.) COLLECTEES AU CENTRE ET CENTRE-OUEST DE LA COTE D’IVOIRE

Morphological characterization is a first approach to the study ofgenetic diversity. Nine hundred twenty maize accessions collected in thecenter and center-west of Côte d'Ivoire, were evaluated morphologically in ablock randomized design. Thirteen morphological descriptors were used inthis study. The descriptive analysis revealed a significant diversity amongaccessions, marked by a significant gap between the minimum andmaximum values. The principal components analysis summarized theinformation contained in the thirteen variables into 3 components that render78.28% of the total variance. The hierarchical clustering allowed us todistinguish two main groups based on early and plant height. Each group wassubdivided into 4 subgroups. Descriptive discriminant analysis showed thateight variables (days to 50% pollen shedding, days to 50% silking, plantheight, ear height, leaf number, number of kernels per row, length of ears),contribute most to discriminate the different subgroups. Different subgroupscan serve parents in the creation of improved varieties

Prospection, Collecte, Nomenclature Paysanne Et Caracterisation Des Variables Qualitatives Des Varietes Locales De Maïs (Zea Mays L.) Cultivees En Cote d’Ivoire

Ivoirian landraces of maize were maintained for several centuries in different ecological conditions, which allowed them to accumulate a large genetic diversity yet little studied. This study aims to make a first inventory of the existing diversity and establish a representative collection of the diversity of this crop in Côte d’Ivoire. Surveys and collection of maize landraces were conducted in three agro-ecological zones of Côte d'Ivoire. Two hundred and forty seven villages were selected and prospect in twentyfour regions. In each village, passport data were collected using the tools and methods of participatory research. A sample of 829 maize accessions were collected. The preliminary characterization of this collection was performed based on the descriptors of maize developed by Bioversity International. The study revealed a significant varietal diversity. Five varieties have been identified based on the color of the grains: yellow maize, white maize, red maize, purple maize and variegated maize. Varieties with yellow grain, with a percentage of 54.16% have been the most prevalent in different areas surveyed. Varieties with purple and red grain have been rare, with respective numbers of 3.38 and 3.62%. Interviews conducted with producers have permitted to inventory 81 local names. The main criteria of farmers to characterize local ecotypes was grains color. The collected accessions are an important gene pool for the present and future generations in the context of plant breeding work

Genetic diversity and population structure of maize landraces from Côte d’Ivoire

Maize (Zea mays L.) occupies an important place among food crops in Côte d’Ivoire. However, no study on the genetic diversity of the species has been performed to date. This study aims at analyzing the diversity and genetic structure of 35 maize accessions using 10 microsatellite markers. These accessions are from different agro-ecological zones representative of the Ivorian territory. The results showed that for all accessions studied, 47 alleles were detected, with an average of 6.71 ± 2.21 alleles per locus. The percentage of polymorphic loci and total genetic diversity, were 91.34% and 0.524 ± 0.159. A slight excess of heterozygotes was observed in the accessions (4.6%). The molecular analysis of variance showed that the total genetic diversity is mainly due to the intra-accession diversity (85.17%). The inter-accession diversity rate was estimated at 14.87%, which is in favor of moderate differentiation between the accessions. The Bayesian analysis grouped the accessions into two populations, regardless of geographical origin. These results provide basic information potentially useful in selection. The cross between two individuals from different groups might help exploit the phenomenon of heterosis.Key words: Ex situ conservation, Côte d’Ivoire, genetic diversity, maize, microsatellite marker

Evaluation of agro-morphologic diversity of some accessions of eggplant (Solanum melongena), some wild and cultivated relatives and their interspecific hybrid progenies

[EN] Commercial varieties of eggplant, Solanummelongena, are vulnerable to future challenges related to the effects of climate change. It is therefore important to provide plant breeders and farmers with plant material that can meet these new challenges by exploiting some of the natural abilities of wild relatives.The aim of this study was to appreciate the transmissibility of interesting traits to the descendants by evaluating the agro-morphologic diversity of 8 accessions of S. melongena, 8 accessions of 6 wild or cultivated relatives and 36 interspecific progenies. Mean values of agro-morphologic traits revealed heterosis effects for vegetative growth characteristics in interspecific hybrids between S. melongena and wild relatives. A Principle Component Analysis identified three morpho-groups that discriminate S. insanum, S. anguivi and S. dasyphyllum, the respective wild ancestors of the three main cultivated eggplant species, S. melongena, S. aethiopicum and S. macrocarpon. In addition, interspecific hybrids belong to the same morpho-groups as the wild parental accessions, which could therefore carry dominant alleles of genes controlling the expression of these agro-morphologic traits. In general, fertile interspecific hybrids have values of production characteristics intermediate between those of parental accessions, suggesting the involvement of genes with additive effects in the expression of these traits.This work was undertaken as part of the initiative Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives, which is supported by the Government of Norway. The project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew and implemented in partnership with national and international gene banks and plant breeding institutes around the world. For further information, see the project website: http://www.cwrdiversity.org/.Kouassi, KBA.; Kouassi, AB.; Prohens Tomás, J.; N'gbesso, MFDP.; Akanvou, L.; N'guetta, AS.; N Zi, JC.... (2019). Evaluation of agro-morphologic diversity of some accessions of eggplant (Solanum melongena), some wild and cultivated relatives and their interspecific hybrid progenies. Global Journal of Advanced Research. 6(1):10-19. http://hdl.handle.net/10251/156953S10196

Systems approaches to innovation in pest management: reflections and lessons learned from an integrated research program on parasitic weeds in rice

This paper provides a retrospective look at a systems-oriented research program, on the increasing occurrence of parasitic weeds in rainfed rice in sub-Saharan Africa, to qualitatively assess merits and identify challenges of such approach. We gained a broad contextual overview of the problem and different stakeholders' roles, which enabled identification of entry points for innovations in parasitic weed management. At the crop level parasitic weed infestation is associated with poor soil fertility and water management. Farmers' infrequent use of inputs to control them was caused by various factors, ranging from fears of undesired side effects (agronomic) to a lack of quality control of products (institutional). Furthermore, there may be enough extension agents, but they lack the required training on (parasitic) weed management to provide farmers with advice, while their organizations do not provide them with the necessary means for farm visits. At even higher organizational levels we observed a lack of coherent policies on parasitic weed control and implementation of them. Merits and challenges of an integrated multi-stakeholder and multi-level research project are discussed

Distribution des espèces de

Les cultures céréalières sont pour la plupart infestées par des espèces de Striga dans le nord de la Côte d’Ivoire. Dans cette étude, les espèces de Striga, leur répartition, abondanceet intensité d’infestation ont été déterminées. Les surfaces de céréales infestées ont été estimées. Les données ont été collectées à travers des enquêtes extensives et intensives. Des échantillonnages ont été réalisés dans des champs cultivés. Selon la carte des zones d’infestation de Striga actualisée, les zones infestées couvrent le nord du pays de 8°47, 17’ à 10°38, 84’ de latitude nord et de 2°47, 68’ à 7°55, 20’ de longitude ouest. La zone infestée occupe une superficie cultivable de 3 191 850 ha. Un total de 71, 8 % des villages situés dans cette zone sont infestés par Striga spp. L’hypothèse d’évolution des infestations suivant un gradient nord-sud a été confirmée. Les infestations ont commencé en zone de savane soudanienne et ont atteint la moitié de la zone de savane sub-soudanienne. Striga hermonthica est l’espèce la plus abondante (97, 1 %) dans les cultures céréalières, suivie par Striga aspera (2, 0 %) et Striga asiatica (0, 9 %). Striga gesnerioides n’a pasété observé dans les cultures de niébé. Des types de S. hermonthica et S. aspera à fleurs blanches ont été recensés. Le morphotype de S. asiatica à fleurs rouges a été trouvé parasitant le riz pluvial. S. hermonthica constitue la contrainte majeure à la production céréalière dans le nord du pays où il infeste sévèrement 57, 2 % (268 250 ha) de terres dévolues au maïs (108 160 ha), mil (38 300 ha), sorgho (30 360 ha) et riz de plateau (91 430 ha). Les taux d’infestation des cultures de mil, de maïs, de sorgho et de riz de plateau ont été respectivement de 65, 9 %, 56, 5 %, 51, 0 % et 40, 5 %. Le Striga constitue un frein à la production de ces céréales et représente donc une menace pour la sécurité alimentaire dans les zones infestées

Effect of conservation methods on the mineral contents of some maize varieties (Zea mays L.) produced in Côte d’Ivoire

Objective: The aim of this study was to evaluate the effect of conservation methods on the mineral content of some maize varieties during post-harvest storage. To meet the needs for the human and animal consumption, it is necessary to determine the mineral contents of raw materials.Methodology: Eight maize varieties, including two local varieties used as controls (“Violet de Katiola” and AC176) and six improved varieties (Obatanpa, MDJ, EV8728, GMRP18, Acr97TZLcomp-1w and Acr97TZLcomp-1wsynth), produced by the Centre National de Recherché Agronomique (CNRA), were stored according to three preservation methods (granary, attic and jute bag) during 120 days. Sampling was performed every 30 days, followed by chemical analyses.Results: The ash contents of local varieties were better preserved in the granary than in the attic or the jute bag because no significant variation was observed at the end of the preservation time. In improved varieties, all the ash contents varied. Concerning constitutive minerals, magnesium and calcium contents were preserved in all varieties respectively during 30 and 120 days of storage in the granary, the attic and the jute bag. On the other hand, some variations were observed for potassium and phosphorus contents. For example, “Violet de Katiola” potassium content was best preserved in the jute bag during 120 days; AC176 and EV8728 potassium contents were best preserved in the attic respectively during 90 days and 60 days. The three preservation modes were suitable to maintain ACr97 comp1wsynth potassium content between 60 and 120 days; but in this variety, phosphorus was best preserved in the attic during 90 days.Conclusion: The three modes of maize grain storage were suitable to preserve magnesium and calcium contents of local and improved varieties and Acr97TZLcomp1-wsynth potassium content.Keywords: Maize, variety, mineral content, preservation, period, Côte d’Ivoire

Crop Adaptation and Improvement for Drought-Prone Environments

https://newprairiepress.org/ebooks/1049/thumbnail.jp

Towards conservation and sustainable use of an indigenous crop: A large partnership network enabled the genetic diversity assessment of 1539 fonio (Digitaria exilis) accessions

International audienceThe use of neglected and underutilized species (NUS) in agrosystems is a potential solution to the challenges arising from global change. These species could contribute to the equitable diversification of agricultural systems. Providing knowledge on their genetic diversity and fostering access to data and results is essential for the development of strong collaborative future research. The study addressed these issues by assessing the diversity of the largest fonio (Digitaria exilis) collection existing to date. Associated with a user-friendly Shiny application (https://shinyapps.southgreen.fr/ app/foniodiv), our results reinforce research efficiency and broaden the prospects for all actors involved in enhancing fonio and indigenous crops as valuable resources for the future

Towards conservation and sustainable use of an indigenous crop: A large partnership network enabled the genetic diversity assessment of 1539 fonio (Digitaria exilis) accessions

<p>The use of neglected and underutilized species (NUS) in agrosystems is a potential solution to the challenges arising from global change. These species could contribute to the equitable diversification of agricultural systems. Providing knowledge on their genetic diversity and fostering access to data and results is essential for the develop- ment of strong collaborative future research. The study addressed these issues by assessing the diversity of the largest fonio (<i>Digitaria exilis</i>) collection existing to date. Associated with a user-friendly Shiny application (https://shinyapps.southgreen.fr/ app/foniodiv), our results reinforce research efficiency and broaden the prospects for all actors involved in enhancing fonio and indigenous crops as valuable resources for the future.</p&gt