Secondary metabolites of plants widely used in the medicinal and cosmetic industries, can be produced by tissue culture. In vitro production of these secondary metabolites is affected by various factors such as the type and concentration of phyto regulators. In this study, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methoxy-3,6-dichlorobenzoic acid (Dicamba) effect on phenolic compounds synthesis as well as Phenylalanine ammonia lyase (PAL), tyrosine ammonia lyase (TAL), Polyphenoloxidase (PPO), peroxidase (POD), Catalase (CAT) and Ascorbate Peroxidase (APX) activities from root explants have been studied. The root explants come from the seeds in vitro germination of maize irradiated (200 and 300 grays) or not irradiated (control) with gamma radiation. The results obtained showed that the auxin type had a very highly significant effect (p <0.001) on all parameters studied. Callus induced on medium containing 2,4-D gave a higher content of phenolic compounds, PAL, TAL, PPO, POD, CAT and APX than callus induced on medium containing dicamba. The highest content of total phenols (76.971 µmol/g fresh callus) was obtained in callus from 300 grays. By cons, the contents of POD, PAL, TAL, CAT and APX (4.034; 0.031; 0.145; 1315.596 and 2461.714 mmol/min/g fresh callus) were obtained in callus from 200 grays.

Groundnut (Arachis hypogaea), cowpea (Vigna unguiculata) and soybean (Vigna radiata) are the main food legumes grown in Côte d'Ivoire and the localities of Haut-Sassandra. These legumes are highly valued for their nutritional, agronomic and economic value. Groundnut, cowpea and soybean are the main food legumes grown in Côte d'Ivoire and in the localities of Haut-Sassandra. On the other hand, Ivorian soils are characterized by a tendency towards acidification and a decrease in the content of nutrients such as phosphorus and nitrogen which have a direct impact on the products. To restore soil fertility, farmers use mineral fertilization. However, this fertilization has an influence on the nodulation of these legumes. The study took place at Jean Lorougnon University. We adopted a completely random experimental block device. The parameters measured included the number of nodules, the length and weight of the plant, the length and weight of the root system. Our results showed that mineral fertilization reduced the nodulation capacity of legumes. However, a small dose of phosphorus (<2 g) would be required for early growing legumes.

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An agronomic test was conducted at the CNRA-Bimbresso research station in order to assess the vegetative behavior of rubber plants on compost-based growing media. To this end, after composting, four compost-based substrates and two soil-based controls were made and tested in a bag nursery. The follow-up of the experiment focused on the evaluation of the vegetative growth parameters and the rates of graftable plants, of grafting success and of transferable plants in the field. The results obtained reveal that the parameters of vegetative growth (diameter at the collar, height of the plants) and the rates of graftable plants and of success in grafting have been improved in rubber plants grown in compost-based substrates compared to control plants. The production of the rubber plant material was optimal with the dose of compost of 300 g or 27 t.ha -1 which, under the conditions of this study, may be the dose recommended on rubber plants in bag nursery.

Maize (Zea mays), is a plant of economic and nutritional interest, which is often confronted with unfavorable environmental conditions, including water stress. This phenomenon forces the plants to considerably reduce their production by disturbing their metabolism. Seeds of maize of the variety EV8728 were subjected to different doses of gamma radiation (100, 200 and 300 grays) in order to induce mutations in plants that could lead to resistance to water stress. Thus, plants from gamma irradiated seeds were used to evaluate the impact of water stress on leaf physiological parameters (leaf area, density and pore area of stomata and assimilatory pigments). Water stress had a depressive effect on all leaf parameters in maize plants. The degree of sensitivity or tolerance of the plants depends on the dose of irradiation and the intensity of stress applied. The increase in the level of water stress reduces the leaf surface and that of the stomata pores. This in turn increases the density of stomata. In addition, chlorophyll a was more sensitive to the effect of water stress than chlorophyll b.