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

Effects of seed fermentation method on seed germination and vigor in the oleaginous gourd Lagenaria siceraria (Molina) Standl.

Supplying high quality seed to rural farmers is the basic requirement for the sustainable development of agriculture in developing countries. The present study was conducted to examine the influence of Lagenaria siceraria seed fermentation method on seed germination and vigor. Three seed fermentation methods (fermented in ambient air, plastic bag stored in ambient or in plastic bag buried) were tested on two cultivars during two years. Seed germination and vigor were better when fermentation was conducted in anaerobic, darkness, and at low temperature. Low seed quality was observed in unfermented seed, suggesting the occurrence of postharvest maturity in L. siceraria. Seed quality did not vary between cultivars. Regardless of the fermentation process and cultivars used, the best seed and seedling qualities were observed when the amount of rainfall during the experiment period was high, suggesting that wet soil is necessary for an on farm reliable evaluation of seed fermentation method in the bottle gourd L. siceraria.Keywords: Cucurbit, egussi, maturity, minor crops, oilseed, seedling, viability

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

Flowering phenology and yield-related traits in an interspecific cross between Coffea pseudozanguebariae Bridson and C. canephora Pierre

Higher caffeine content and cup beverage bitterness considerably depreciated the commercial value of Coffea canephora Pierre (CAN) compared with C. arabica L (ARA). Wild caffeine-free species like C. pseudozanguebariae Bridson (PSE) offer the opportunity to produce new CAN varieties containing little or no caffeine. F1 plants resulting from a PSE × CAN cross, and BC1 individuals, derived from the first backcross generation (PSE × CAN) × CAN) were produced. In order to assess flowering phenology and yield traits in F1 and BC1 hybrids, six morphological characters including flowering time, pollen viability (PV), fructification rate (FR), seed set (SSET), flower number per node (NFN) and 100-bean weight (W100) were studied under environmental conditions in Côte d’Ivoire. The results showed that F1 plants flowered only in February while, for BC1, 20% and 80% of the plants flowered in January and February, respectively

Assessment of the genetic diversity conservation in three tall coconut (Cocos nucifera L.) accessions regenerated by controlled pollination, using microsatellite markers

Controlled pollination process is used during the regeneration of ageing accessions in the International Coconut Genebank for Africa and Indian Ocean (ICG-AIO). The effectiveness of this process has not yet been evaluated. This study aimed to evaluate the effectiveness of controlled pollination method by investigating the level of molecular resemblance between the regenerated (G1) and parental (G0) populations of three tall coconut accessions, Mozambique Tall (MZT), Gazelle Peninsula Tall (GPT) and Tahitian tall (THT) using 15 microsatellites (SSR) markers. The results indicate a relative reduction of gene diversity during regeneration. It decreased from 0.690 to 0.587, but, low values of Jaccard’s dissimilarity index were found between regenerated and parental populations of tall coconut, varying from 0.072 to 0.133. Low values of genetic diversity between G0 and G1 tall coconut accessions (DST), ranging from 0.005 to 0.007, were recorded. Consequently, using controlled pollination technical as regeneration method of the genebank is effective for satisfying maintenance of the genetic integrity of the original coconut accessions.Keywords: Tall coconut palm, controlled pollination, regenerated accessions, genetic diversity, microsatellites markersAfrican Journal of Biotechnology Vol. 12(20), pp. 2808-281

Genetic relationships among accessions of African indigenous melons (Cucumis melo L. ssp. agrestis) using AFLP markers

Cucumis melo ssp. agrestis is among the most important cucurbit consumed in Côte d'Ivoire. Two varities were identified and used in different areas. One is eaten as soup thickener and the second is used as vegetable. In spite of the socio cultural importance of this species, knowledge of its genetic diversity and differentiation is very poor. little information is available on the variety itself or relationships between the both varieties. Amplified fragment length polymorphism (AFLP) markers were employed to determine the genetic relationships between these varieties in Côte d'Ivoire. Five AFLP primer combinations were used for this study. A total of 75 loci were observed in the 24 accessions with 82.16 % of polymorphic loci ranging between 13.3 % and 100 %. The averages of total gene diversity (HT) and within accessions genetic diversity (HS) were 0.313 and 0.273 repectively. The inter accessions genetic diversity (DST) and the coefficient of gene differentiation among cultivars (FST) were 0.040 and 0.129 respectively. Cluster analysis using Unweighted Pair-Group Method using Néi's genetic distance highlighted two main clusters indicating clearly separation between vegetable and thickener cultivars of Cucumis melo L. ssp. agrestis consumed in Côte d'Ivoire. These data are useful for best management of genetics resources of Cucumis melo L. ssp. agrestis

Determination of the genetic structure of the oleaginous Lagenaria siceraria of the Nangui Abrogoua University Germplasm collection

peer reviewe

Identification of Fungus Flora Associated with Lagenaria Siceraria (Molina) Standl in Côte d’Ivoire

Lagenaria siceraria (Molina) Standl is a cucurbit which seeds are consumed by people in rural and urban Africa. This plant is subjected to a strong parasitic and diseases pressure that reduces seeds production. Efficient fight against plant parasite, particularly fungus is a prerequisite for an improved productivity. This study was undertaken in five localities (Alepe, Bondoukou, Bongouanou, Divo and Korhogo) belonging to three agroecological areas of Côte d’Ivoire. The aim was to identify fungal genera infecting L. siceraria in order to design an efficient control measure. Leaf samples with necrosis and discoloration symptoms were collected throughout the localities and subsequently, fungus were isolated and identified in laboratory. From a total of 750 samples collected, 7 types of symptoms were distinguished. Fungal genera found in all of the localities were Aspergillus, Botryosphaeria, Cochliobolus, Colletotrichum, Fusarium, Lasiodiplodia and Phoma. Only Pestalotiopsis was specific to the locality of Divo. An ANOVA test performed on the data showed a significant difference between fungal genera in terms of isolation frequency. Principal components analysis revealed that fungus distribution in each locality was correlated with climatic factors