La patate douce est une culture négligée alors que sa contribution dans la sécurité alimentaire est importante au Bénin. Ce travail a permis d'évaluer les connaissances paysannes sur la diversité, les contraintes de production, les pratiques agricoles de conservation des tubercules et de gestion du système semencier de la patate à travers 35 villages du Sud-Bénin. La méthodologie a consisté en une recherche participative par des entretiens individuels et de groupe. Les résultats obtenus ont permis de recenser 87 variétés locales sous réserve de synonymie. Le nombre de variétés locales varie de 1 à 12 par village. La plupart des producteurs utilisent la forme des feuilles et la couleur de la peau des tubercules pour reconnaître les variétés. Des réponses obtenues, le fort taux de multiplication (19,32%), la précocité (15,07%), la valeur marchande élevée (16,13%) constituent des critères de sélection des variétés destinées à la production. De même, 7 contraintes majeures parmi lesquelles l'insuffisance de boutures de variétés performantes (19,73%), la rareté des pluies (19,46%), la baisse de productivité (19,10%), ont été identifiées et entravent la production de la patate douce. Par ailleurs, les producteurs ne disposent d'aucune mesure de conservation durable des tubercules. Le système semencier reste traditionnel. © 2016 International Formulae Group. All rights reserved.Mots clés : Ipomoea batatas, Diversité variétale, Critères de préférences, Contraintes, Bénin. Analysis of endogenous knowledge and determinants of sweet potato production [Ipomoea batatas (L.)], a high socio-cultural and economic value culture in Benin ABSTRACTThe sweet potato is a neglected crop while its contribution in food security is an important in Benin. This work has assessed endogenous knowledge on diversity, production constraints, farming pratices of tubers A. M. DOUSSOH et al. / Int. J. Biol. Chem. Sci. 10(6): 2596-2616, 2016 2597 conservations and seed system management of sweet potato through 35 villages of South-Benin. The methodological approach consisted of a participative research for individual and group interviews. The results have identified 87 local varieties under reservation of synonymy. The number of local varieties varies from 1 to 12 per village. Most of farmers use leaf shape and color of the skin of the tubers to recognize varieties. This answers obtained, high multiplication rate (19.32%), precocity (15.07%), high market value (16.13%) are varieties selection criteria for production. Likewise, 7 major constraints among inadequate performance varieties stems (19.73%), lack of rain (19.46%), decreased productivity (19.10%) have been identified and inhibit the production of sweet potatoes. Moreover, producers have no lasting measure to preserve durably tubers. The stem system is traditional.

Aims: This study aims to identify the best surface sterilization and evaluate the effect of haustorium suppression on in vitro germination of coconut palm (Cocos nucifera L.) zygotic embryos. Study Design: Survival rate and contamination rate of zygotic embryos after different surface sterilization treatments, regeneration rate and organogenesis through the number of leaves and the length of shoots after haustorium suppression were determined. For data processing, the Analysis of Variance was used to compare the means which were separated according to Tukey test            (P = 0.05). Place and Duration of Study: Coconut fruits (hybrid PB121) were collected 12 to 14 months after controlled pollination from CRAPP (Centre de Recherches Agricoles Plantes Pérennes), station of Sèmè-kpodji in Benin. Experiments were done in Central Laboratory of Plant Biotechnology and Plant Improvement, University of Abomey-Calavi and conducted from june to december in 2019. Methodology: For the zygotic embryos surface sterilization, four treatments combining three concentrations (3%, 6% and 15%) of commercial bleach (Javel la Croix© containing 12° active chlorine) and immersion durations (5 min, 10 min and 20 min) were tested and the survival rate were determined for each treatment after two months culture. The zygotic embryos were then divided in two sets (haustorium excised embryos set and the whole embryos set) and cultured in modified Y3 medium supplemented with 7 g L-1 agar, 2.5 g L-1 activated charcoal, 5% sucrose,  6.10-3 mM 2.4 D (2.4-dichlorophonoxyacetic acid), gibberellic acid and 0.3 mM BAP(6-benzylaminopurine). After five months culture, the regeneration rate, the number of leaves and the length of shouts were recorded. Results: The high survival rate (80%) was obtained with 6% of bleach and 20 min for the immersion duration without pre-disinfection. The suppression of haustorium have significantly increased the number of leaves (4.3 ± 0.02) and the length of shoots (16.2 ±0.7cm) compared to the whole zygotic embryos. Conclusion: This protocol can help to ensure better surface sterilization of zygotic embryos before their in vitro culture and the development of vigorous plantlets in order to improve the slow growth of plantlets, when transferred to the greenhouse or field.

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