Grapefruit (Citrus paradisi Macf.) is an economic fruit crop worldwide cultivated for its nutritional value, and aromatic flavours. However, the development of new varieties and high production of quality seedling constitutes a limit to improving grapefruit yields. An efficient regeneration protocol could be of great interest for grapefruit transformation, micropropagation, and germplasm conservation. In vitro plant regeneration systems of Citrus paradisi have been studied by using cotyledonary explants. Different concentrations of plant growth regulators were used to explore the organogenic potential of cotyledonary explants under laboratory conditions. For indirect organogenesis using cotyledon segment explants, a low concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) lead to the formation of white callus, while a high concentration of 2,4-D induced brown callus and adventitious root differentiation. The best response for callogenesis was obtained on Murashige and Skoog (MS) medium supplemented with 2 mg/L of 2,4-D. Only brown callus cultured on MS added with 2 mg/L 6-benzylaminopurine (BAP) has regenerated shoots, but the percentage of callus producing shoots was very low (6.66 ± 2.68%). Regarding direct organogenesis from the cotyledonary node explants, the best response for shoot proliferation was observed on MS supplemented with 4 mg/L BAP (86.66 ± 12.58% of explants regenerating shoots, and an average number of 5.45 ± 0.45 shoots per explant). Low percentages of In vitro rooting of regenerated shoots were observed with different concentrations of α-naphthalene acetic acid (NAA) or indole-3-butyric acid (IBA). Nevertheless, the highest rooting percentage (13.33 ± 2.88%) was obtained on MS containing 2 mg/L NAA. These results provide new information for mass regeneration and the production of healthy seedlings, and can be applied in grapefruit improvement programs.

Background: Pterorhachis. zenkeri commonly known as “Ayilalou” or “Démareur” is an aphrodisiac plant used by Cameroonian traditional healers to enhance libido and sperm production. This study was undertaken to investigate the aphrodisiac mechanism of P. zenkeri on the contractile activity of vas deferens with regard to its function on ejaculation. Materials and Methods: The proximal parts of rat vas deferens were mounted in a 20 mL organ bath containing Krebs solution at 37°C. Cumulative dose-response curves were recorded with KCl (35-280 mM), adrenaline (7-70 µM) and aqueous extract of P. zenkeri (3,55-21,3 mg/mL). Prazosin (type 1 alpha-adrenergic receptor antagonist, 10 µM), Nifedipine (a specific L-type calcium channel antagonist, 5 µM), 2-AminoethoxydiPhenyl Borate (2-APB, IP3 receptor antagonist, 200 μM) and calcium-free medium were further used to study the mechanism of action. Results: KCl, adrenaline and aqueous extract of P. zenkeri showed a concentration-dependent effect on vas deferens contractibility. Nifedipine and Pazosin partially inhibited the effects of P. zenkeri. In calcium-free medium containing Ethylene Glycol-bis (2-aminoethylether)-N,N,N’N’-tetraacetic acid (EGTA, 1µM), P. zenkeri triggered vas deferens contraction which was completely abolished in the presence of 2-APB. These results suggest that the aqueous extract of P. zenkeri possesses bioactive compounds capable of inducing vas deferens contractions through type 1 alpha adrenergic receptors and mobilization of extra and intracellular calcium. Conclusion: These results confirm the aphrodisiac properties of P. zenkeri through the activation of the emissive phase of ejaculation.

Rising the prevalence of type 2 diabetes mellitus in sub-saharian Africa has necessitated surveys of antidiabetic medicinal plants. Ethulia conyzoïdes is a plant widely used in traditional medicine to treat diabetes. However, the different mechanisms by which it exerts its antidiabetic effects remain unknown. Thus, this study aimed to investigate the effect of Ethulia conyzoïdes aqueoux extract on dexamethasone-induced insulin resistance in Wistar rats. Insulin resistance was induced by intraperitoneal injection of dexamethasone (1mg/kg) for 8 days and the animals received simultaneously, orally, distilled water (insulin resistant control group) and, metformin (100 mg/kg) or Ethulia conyzoïdes aqueoux extract at doses of 133 and 266 mg/kg. Normal control rats received NaCl 0.9% (intraperitoneal by injection) and distilled water orally. Insulin sensitivity, total cholesterol, triglycerides, transaminases activity and redox status were evaluated. Results showed a significant reduction of insulin tolerance (p<0.001), a drastic increased of transaminase activity (p<0.05), hyperlipidemia, and a great potentiation of liver antioxidant enzymes (GSH, SOD and catalase) in insulin resistant control group. Ethulia conyzoïdes aqueoux extract markedly improved insulin sensitivity and reversed all the modified parameters. This study demonstrated the efficacy of Ethulia conyzoïdes aqueoux extract to improve insulin sensitivity and manage biochemical disorders induced by insulin resistance. Short term administration of dexamethasone appears to stimulate the first line antioxidant defense in order to counteract oxidative stress, meaning that Ethulia conyzoïdes aqueoux extract inhibited free radicals production.

Cyperus rotundus Linn. is a potentially valuable aromatic plant given its ability to synthesise essential oil and the variety of traditional uses associated with it. The valorisation of this plant would imply the exploitation of a significant quantity of its biomass, which cannot be obtained from the wild. The aim of this study was to determine the best methods for regeneration and the development phases of C. rotundus, in order to ensure the continuous availability of its biomass. The mode of natural regeneration and the state of domestication of C. rotundus by local populations were investigated through surveys of traditional healers and herbalists. In addition, ex situ regeneration trials were carried out using vegetative propagation from bulbs and seed germination. The vegetative propagation was assessed by estimating the lag time and percentage regeneration of the bulbs, while the seed germination percentage was evaluated. The development phases of the plant were identified following the BBCH (Biologische Bundesanstalt Bundessortenamt and CHemische Industrie) scale. The yield was calculated from the underground biomass of the bulbs produced at the end of the plant life cycle. The results showed that C. rotundus regenerates naturally from bulbs and rarely from seeds. In the Western Highlands of Cameroon, traditional practitioners and herbalists have begun domesticating C. rotundus on a small scale. Propagation attempts from seed were unsuccessful in the present study. However, from bulbs, a lag time of 10 days was observed and a regeneration percentage of 88% obtained after 47 days. Five phases of development were identified including emergence (0), bolting (1), flowering (2), maturation (3) and senescence (4). The production of bulbs, which are organs containing the essential oils, was observed from the bolting phase. The biomasses of about 383, 493 and 520 kg/ha were obtained during phase 1, 2 and 3 respectively. The best propagation method and the development phases of Cyperus rotundus investigated in this work could contribute to an advance in the domestication process in order to ensure its availability and sustainability.

Post-harvest food losses remain a major problem in sub-Saharan Africa. A study of local storage structures aimed at carrying out a diagnostic analysis of post-harvest losses in grains and seeds in the Bamboutos department, West region, Cameroon. A questionnaire survey was carried out among 240 producers in 12 villages, spread over 3 subdivisions. Air temperature and relative humidity data were collected over 80 days at two storage stores in this study area. Twelve samples of food infested by insect were taken and deposited in the entomology laboratory of the Faculty of Agronomy and Agricultural Sciences at Dschang University for identification. It emerges from this investigation that corn is the only grain stored by producers. Beans and peanuts are mostly stored seeds, while pistachios and soybeans are seeds stored by few farmers. Three structures are used for grain storage: granaries (86.25%), cribs (10.42%) and stores (3.33%). Among the containers, two are mainly used for seed storage: barrels (58.38%) and bags (39.25%); buckets with lids are used by a few farmers (2.36%). The storage period of corn is between 8 and 12 months. The storage period of peanuts is between 6 and 8 months and beans between 4 and 5 months. The use of chemicals, inert matter (ash) and plant substance (neem) are the three methods of protection used in Bamboutos. Bamboutos storage stores promote the development of molds and insects. Three major groups of biological agents are responsible for spoilage: insects (Callosobruchus maculatus F., Sitophilus zeamais M. and Acanthoscelides obtectus S.), rodents (Rattus norvegicus, Rattus rattus and Mus musculus) and molds. Insects are the pests that cause the most damage to stored products according to 55.42% of producers. According to 23.58% of producers, it is rodents and 15% molds. Farmers estimate that the damage to the stock is between 7% and 30% after destocking of maize. This damage is between 2% and 5% after removal of beans from storage and less than 3% after removal of peanuts. Farmers underestimate the damage caused by pests on corn, which is around 40% after 10 months of storage in granaries. It is therefore essential for Cameroonian farmers to master and respect the storage techniques according to the storage structures and the foodstuffs stored.

The aim of this work is to make a preliminary inventory of chiropteran reservoirs of infection in the Republic of Guinea: Boké, Conakry, Faranah, Mamou, Kindia and N'zérékoré. The study was conducted from January 1, 2016 to December 31, 2019. One thousand chiropterans were captured with fishing nets, mist nets or by hand and divided into 18 species and 6 families. Identification was based on the reference collection of IRBAG, Rosevear DR, Hayman RW and Bergmans W.The most representatives were: Hipposideros caffer (15.5%), Mops condylurus (10.8%), Nycteris hispida (7.7%), Neoromicia guineensis (6.8%), Hipposideros jonesi (6.3%), Chaerephon nigeriae (4, 9%), Rhinolophus guineensis (4.2%), Chaerephon pumillus (3.3%), Eidolon helvum (2.6%), Epomophorus gambianus (1.9%), Hipposideros abae (1.3%). On the other hand, the least encountered are: Scotophilus diganii (0.8%), Lissonycteris angolensis (0.7%), Rhinolophus alcyone (0.5%), Rousettus aegyptiacus (0.4%), Scotophilus leucogaster (0.4%) and Neoromicia brunnea (0.2%). These species represent the bulk of the chiropterans fauna, which may play an epidemiological or predatory role for crops and harvests.

Eleven compounds (1-11) were isolated from the methanolic extract of leaves and bark of <i>Senna</i> <i>siamea</i>. Benzylation of compound 2 gave two new hemi-synthetic derivatives: 4'-O-benzylvitexin (12) and 7,4'-O-dibenzylvitexin (13). The structures of these compounds were established on the basis of their spectroscopic (1D and 2D NMR) and mass spectrometric (FAB-TOF-MS) data. The extracts, fractions, some of the isolated compounds as well as hemi-synthetic derivatives were evaluated for their antibacterial activity using broth microdilution method. They were also tested for their antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging potential and ferric reducing antioxidant power (FRAP). The ethyl acetate fraction of the stem bark showed moderate activity) against E. faecalis and P. mirabilis with MIC value of 256 μg/mL. Compound 6 showed moderate activity toward P. mirabilis (MIC = 64 μg/mL). The methanolic extract from bark (EC50 = 1.58 ± 0.25) μg/mL, its ethyl acetate (EC50 = 1.12 ± 0.67) μg/mL and n-BuOH fractions (EC50 = 1.02 ± 0.87) μg/mL as well as n-BuOH fraction from leaves (EC50 = 1.24 ± 0.33) μg/mL were more active against DPPH compared to vitamin C. Compound 4 was the most active against DPPH (EC50 = 1.05 ± 0.38) μg/mL.

This study aimed at evaluating the effects of combined application of dewatered sewage sludge (SS) and mineral fertilizer on the chemical properties of the soil and growth of <i>Zea</i> <i>mays</i>. Six treatments: T0, negative control; T1, positive control of 120 kg N/ha; T2, 2 t/ha sewage sludge (SS) + 60 kgN/ha; T3, 4 t/ha SS + 60 kgN/ha; T4, 8t / ha SS+ 60 kgN/ha and T5, 8 t/ha SS were applied in completely randomized block experimental design. The following parameters: height of plants, diameter of stem, number of healthy leaves, leaves area index, root and shoot biomasses were measured on plants at 30, 44 and 58 days after sowing. For the soil parameters, electrical conductivity (EC), redox and hydrogen potentials were measured at the same frequency. The results showed that the height, the stem diameter, the number of leaves, the leaves area index and the biomass of Zea mays increased in response to soil supplementation with sewage sludge combined with mineral fertilizers. The treatment that best stimulated the growth of maize was T4 (8t/ha SS+ 60 kgN/ha). The soil chemical properties were modified by sewage sludge application. In general, pH and conductivity decrease with sludge application, while, redox potential increased. This shows that combined sewage sludge to NPK (20 10 10) leads to changes in chemical parameters of the soil and thus, influencing the nutrients uptake by plants to improve their growth.


 
 
 
 A cross-sectional and retrospective survey was conducted from September 2021 to January 2022 in the provinces of Chari-Baguirmi and Mandoul (Chad) aiming at analyzing the husbandry and breeding features of Fulani sheep. A total of 144 sheep keepers owning the Fulani sheep breed were surveyed on the basis of their willingness to freely participate. Results show that the respondents belong in majority to Arab and Fulani ethnic groups. Youths and adults were the major groups of keepers (74.98%) followed by the group of above 50 years old (25%). The majority of respondents were married (98.1%). Monogamous families were more represented (63.19%) followed by polygamous families (34.72%). Large majority did not attend formal instruction level (61.80%), followed by 38.20% (either in Arabic or in French). Small family to medium family sizes were more represented (73.91%) compared to larger family size (27.07%). The main activity was livestock husbandry (91.66%), followed by crop production (69.44%) as a secondary activity. Inheritance and purchase constituted the mode of acquisition of Fulani sheep. Mobility was largely based on transhumance (95.48%) for pastoral lands (61.80%) and water sources (40.97%). About 93.75% of sampled herders were homeless and about 6.24% of them stock their flocks in paddocks made up of thorns. Natural carbonate soda source known as “Lime” was used as a mineral supplement in the rainy season by 45.76% of respondents (August-September). Groundnut cake (23.3%), cereal bran (18.21%) and cottonseed cake (11.86%) were used during the lean season (March-May) as supplementary feeds. Combined prophylaxis (vaccination and deworming) and deworming was practiced respectively by 55.54% and 15.6% as opposed to 26.48% who were reported to be without prophylaxis. Keeping the Fulani sheep was provided by family labor 54.5% followed by permanent employees who were mostly Fulani shepherds (29.72%). In terms of exploitation, reproduction (85.02%) was the main source to maintain flocks, where sales (40%), mortalities (29.4%) and slaughtering (19.5%) were the main factors affecting decrease in flock size. This study provides a better perception on the farming and breeding practices of the Fulani sheep of Chad. Thus, the sustainable use and enhancement of this sheep genetic resource require a better understanding of both phenotypic and molecular characteristics.
 
 
 

Canarium schweinfurthii is one of the agro-forestry tree species with multiple uses in the subtropical countries which is still exploited wild. The purpose of this study was to get insights related to peasants' perceptions on the socio-economic importance and cultivation practice of the species in the Western Highlands of Cameroon. The methodology consisted of surveys among people spread over 7 villages. Two hundred (200) people who were involved in C. schweinfurthii exploitation were selected in the study area following a random approach and interviewed using a structured questionnaire. In addition to the identification of respondents, the information collected from interviewees focused on: 1) knowledge, uses, harvesting methods and the impact of the exploitation of the species on the well-being of people; 2) the trend of the population’s dynamics of the species and, 3) the know-how and practices in the cultivation of the plant. The results showed that almost all the interviewees (99%) knew the species that they exploit in six categories of use (food, medicine, handicraft, construction, timber industry and firewood supply), with a broad consensus (Cs = 0.98) for the use in food. The degree of consensus remained low for its use in medicine (Cs= -0.18), firewood supply (Cs= -0.21), timber industry (Cs= -0.65), construction (Cs= -0.77) and handicrafts (Cs= -0.84). According to 80% of respondents, income from the sale of the fruits significantly contributes to household welfare. The most cited harvesting method was fruits picking, which does not endanger the species. Only 37% of the interviewees perceived a regressive trend in the dynamics of the species' population over the last decade. For 71% of the respondents, the cultivation practice by farmers is rare or even non-existent. The main reasons for non-cultivation of the species are the uncertainty that the planted trees will bear fruits (80% of respondents) and the long duration of the vegetative growth phase (55% of respondents). 90% of respondents expressed their willingness to adopt the cultivation of the species if these constraints are circumvented. These findings showed that C. schweinfurthii would be an interesting candidate for participatory domestication in the Western Highland of Cameroon, for the intensification of agro-forestry systems. For this purpose, the establishment of an efficient protocol for asexual propagation of fruit-producing individuals is needed.