Caractérisation physico-chimiques des noix et de l’huile des premiers cocotiers (Cocos nucifera L.) PB 121 issus de la culture in vitro d’embryon zygotique plantés en Côte d’Ivoire

Le présent travail vise à évaluer les caractéristiques physico-chimiques de noix et de l’huile d’amande  des premiers cocotiers PB 121 issus de la culture in vitro. Les observations ont été faites sur des noix de troisstades de maturité puis comparées avec celles des cocotiers PB 121 plantés ordinairement (PB 121 O). Il en ressort que les masses des noix PB 121 O sont significativement supérieures à celles issues de culture in vitro (PB 121 V), pendant que celles d’amande sont moins élevées. Les teneurs en huiles augmentent généralement au cours de la maturation jusqu’au rang 25 à 70,80% chez PB 121 O et 69,78% chez PB 121 V. Elles baissent ensuite respectivement jusqu’à 65,44% et 64,78%. Les indices d’acide et d’iode sont moins élevés chez les PB 121 V avec respectivement au rang 24 sont de 5,33 et 33,00% puis 5,89 et 39,98% chez PB 121 O. Les indices de saponification de PB 121 V sont supérieurs à ceux de PB 121 O. L'acide laurique représente l’acide gras le plus abondant des huiles étudiées. L’huile d’amande de PB 121 V qui est plus stable et moins acide est plus appropriée en savonnerie.Mots clés : Cocotier, in vitro, amande, huile

The biochemical characteristics of coconut (Cocos nucifera L.) water during germination

The purpose of this study was to determine the biochemical characteristics of coconut water during germination. The three cultivars most used worldwide were studied; West African Tall ‘WAT’, Malaysian Yellow Dwarf ‘MYD’ and improved ‘PB121+’ hybrid. Germinated ‘MYD’ and ‘PB121+’ had the greatest physical characteristic (water weight). As for the chemical parameters, the amounts of total sugar fluctuated from 25.60 mg/ml to 50.85 mg/ml while the amount of ashes and pH varied from 0.25% to 0.47% and 6.36 to 6.97 respectively. Coconut water from the ‘WAT’ and from the ‘PB121+’ hybrid which is richer in sugars and ashes is appropriate for vinegar making. It could be also used as an additive in food for children suffering from mineral deficiencies.Keywords: Biochemical parameter, cultivar, nut, hybri

Physicochemical characteristics of kernel during fruit maturation of four coconut cultivars (Cocos nucifera L.)

Physicochemical characteristics of kernels from four cultivars of coconut were studied with the aim of increasing the value of coconut palm (Cocos nucifera L.), the main income of most equatorial coastal farmers. Studies were undertaken on West African Tall (WAT), Malaysian Yellow Dwarf (MYD), Equatorial Guinea Green Dwarf (EGD) and the improved PB121 hybrid, PB121+. Analyses were concerned with kernel weight, thickness, dry matter, oil, proteins and soluble sugars content at six stages (ranks) of nuts maturity. Chromatographic profiles of fatty acids of extracted oils were also determined. The results showed positive interaction between cultivar and maturity stage for all examined parameters. Then, PB121+ nuts, without kernel at the beginning of maturation, had the greatest weight (358.7 g) at rank 26. Kernel thickness was maximum (13.28 mm) in WAT at rank 26 due to nuts complete maturity. Oil content increased until the highest value of 73.01% in WAT at rank 23 before decreasing. Total soluble sugars, essentially non-reducing sugars, were maximum (9.09 g/100 g) in MYD fruits at rank 26. The fatty acids profiles showed an increasing proportion of lauric acid during nuts maturation. These results indicated the possibility of specific utilisations of coconut kernels according to cultivar and maturity stage

Microsatellite gene diversity in coconut (Cocos nucifera L.) accessions resistants to lethal yellowing disease

One of the problems faced in coconut cultivation is the lethal yellowing disease. Experimental trials, conducted in endemic region, showed that the Vanuatu Tall and Sri-Lanka Green Dwarf genotypes weretolerant while the West African Tall appeared susceptible to the lethal yellowing disease. Genetic differences between these tolerant genotypes and the susceptible ones were evaluated using twelvemicrosatellite markers. This work aimed to use identified materials as reference to select suitable parents for gene mapping studies. A total of 58 alleles were detected at the 12 microsatellite loci. Thenumber of alleles varied from 3 to 7, with an average of 4.83 alleles. The Fst index revealed that 59.70% of the total allele variability explained differences between the three accessions. Genotypes of WestAfrican Tall, susceptible to the lethal yellowing disease, were less genetically clustered to the genotypes of the two tolerant accessions. This differentiation was based on specific alleles and frequency variation of shared allele in the three accessions. This molecular typology was useful as reference for large molecular screening of coconut genetic resources and the identification of suitableparents for the development of mapping populations for tagging the lethal yellowing resistance genes

Effect of fruit set on fructification of coconut tall ecotypes for production of hybrid seednuts in Cote D'Ivoire

To assess the effect of coconut fruit set on the variation expression of the number of nuts yielded at the end of the fructification, a modelling approach was used. Four female parents namely Kar Kar Tall (KKT), Kappadam Tall (KPD), Sri Lanka Tall (SLT) and Vanuatu Tall (VTT) as well as four male parents known as Panama Aguadulce Tall (PNT01), Rennell Island Tall (RIT), Tagnanan Tall (TAG) and West African Tall (WAT) were involved in six crosses. The WAT was used as a control. Results showed that fruit set and fructification was female genotype and crossing-independent. Thus, the four female genotypes can be indifferently used in crossings to produce seednuts. In contrast, pollen age discriminated the male parents into two groups, especially 1) PNT01, TAG and 2) WAT and RIT. Nevertheless, the two latter male parents WAT and RIT, having provided the oldest pollen, did not induce significant differences among crosses. Fruit set explained 83.70% fluctuations of the fructification. Hence, it exerted a significant effect on the fructification variation expression. In Côte d’Ivoire, we could predict the seednuts production coming to maturity from the fruit set using the equation Nut = 0.006 + 0.774*Setfruit.Keywords: Cocos nucifera, modelling, pollen ageAfrican Crop Science Journal, Vol. 21, No. 4, pp. 303 - 31

Effet de la densite sur les parametres dendrometriques D'Acacia auriculaeformis en association avec le cocotier (Cocos nucifera L.) sur sables quaternaires en C&#244te d'Ivoire

No Abstract

Relationship between five climatic parameters and somatic embryogenesis from sporophytic floral explants of Theobroma cacao L.

To analyse the relationship between climatic parameters and somatic embryogenesis (SE), some favourable and unfavourable periods were identified. Likewise, to optimize SE in unfavourable periods the relationship among 2,4-D/TDZ, SE and year was analysed. Staminodes and petals of six hybrids and two clones as controls were sown in bulk onto three different calli induction media. Minimal temperature, rainfall, maximal temperature, mean temperature, temperature gaps, sunshine and relative humidity as climatic parameters were simultaneously recorded the day of the harvest of flower buds. Student-Fisher’s test at 5% level, Principal Component Analysis and Pearson’s linear correlation at 5%, 1% or 1‰ were used to separate the averages, identify the best climatic parameters and analyse the link between the climate and SE, respectively. The relative humidity and mean temperature were eliminated from the study. The period that spreads out from January to September favoured SE. In favourable periods, the SE variation was independent of that of concentration in 2,4-D/TDZ. This shows that these are the metabolites coming from 2,4-D/TDZ that activate the genes rather than these two compounds themselves. In unfavourable periods, in the first year, the weakest concentration in 2,4- D/TDZ of PCG3 medium favoured SE, while in the second year that is the strongest concentration of PCG4 which increased it. This could indicate an interaction among year, concentration in 2,4-D/TDZ and SE. However, the link thus established is only statistical. It did not allow the quantification of the contribution level of these climatic parameters to variations of SE.Key words: Somatic embryogenesis variations, staminodes, petals, PCG calli induction media, favourable and unfavourable periods. 2,4-D/TDZ concentration in periods

Action de l’acide phosphoreux in vitro sur Phytophthora katsurae (Pythiaceae), parasite du cocotier en Côte d’Ivoire

Lfaction in vitro de lfacide phosphoreux sur quatre souches de Phytophthora katsurae provenant de trois regions Sud de production du cocotier en Cote dfIvoire a ete evaluee. Lfetude fongitoxique de lfacide phosphoreux et la capacite de redeveloppement des souches ont ete respectivement realisees sur milieu Ribeiro modifie, amende avec les concentrations 15, 20, 25, 30, 40 et 50 ƒÊg/ml dfacide phosphoreux et avec 15 et 50 ƒÊg/ml du meme acide. Les croissances myceliennes sur milieux amendes a lfacide phosphoreux ont ete comparees aux croissances des champignons sur milieux Ribeiro ne contenant pas de lfacide phosphoreux. Lfactivite fongitoxique de lfacide phosphoreux sfest traduite par des taux dfinhibition compris entre 36,45% et74,64%. Les souches du Sud Comoe issues dfune plantation villageoise de Samo et dfune plantation industrielle CAIMPEX, sont plus sensibles a lfacide, contrairement aux souches de Marc Delorme et Fresco.Les essais realises ont montre egalement que in vitro, les souches sont capables de se redevelopper a lfabsence du fongicide. Cette etude a mis en evidence une activite fongistatique de lfacide phosphoreux. Ces differents comportements pourraient permettre lfoptimisation de la lutte chimique dans toutes les zones de production de la Cote dfIvoire

Systems thinking creates opportunities for a circular economy and sustainable palm agriculture in Africa

Palm agriculture has received strong criticism in recent years due to its link with deforestation, especially in Asia. Here we propose that there is instead an opportunity for sustainable palm futures in Africa. Applying interdisciplinary systems thinking and circular production models, food and economic security can be achieved sustainably by (i) promoting integrated production of nutritionally valuable insect and fungal protein using palm crop waste; (ii) increasing resilience and productivity of crop palms in the harsh tropical climates of sub-Saharan Africa; and (iii) promoting the development of palm plantations as biodiverse agroforestry ecosystems