DiversitÃ© des Champignons Mycorhiziens Ã Arbuscule AssociÃ©s aux Cacaoyers (Theobroma cacao L.) en CÃ´te dâ€™Ivoire - Cyriak Amani, Yves FrÃ©dÃ©ric; Alban Mâ€™bo, Kacou Antoine; Cherif, Mamadou; KonÃ©, Daouda; KouamÃ©, Christophe (European Scientific Journal, ESJ, 2023)
Les champignons mycorhiziens Ã arbuscule vivent en symbiose avec les racines des plantes aidant celles-ci Ã absorber les nutriments nÃ©cessaires Ã leur croissance et dÃ©veloppement. En CÃ´te dâ€™Ivoire, cette symbiose nâ€™est pas prise en compte dans les stratÃ©gies agroforestiÃ¨res Ã base de cacaoyer. Ce travail vise Ã Ã©tudier les mycorhizes associÃ©s aux cacaoyers dans les systÃ¨mes agroforestiers. Les spores et les racines de cacaoyer issus de 32 plantations de cacao localisÃ©es dans les 4 principales zones agro-Ã©cologiques de production du cacao en CÃ´te dâ€™ Ivoire ont Ã©tÃ© analysÃ©es. La diversitÃ©, la densitÃ© des spores, les taux de mycorhization et la richesse spÃ©cifique des mycorhizes ont Ã©tÃ© dÃ©terminÃ©s. Lâ€™examen des spores met en Ã©vidence 72 morphotypes appartenant Ã 10 familles, 17 genres et 49 espÃ¨ces de mycorhize. Claroideoglomus etunicatum est lâ€™espÃ¨ce dominante du verger cacaoyer. Lâ€™abondance des spores varie entre 10,53 Ã 31,24 spores.g-1 de sol pour une moyenne de 18,30 spores.g-1 de sol. Le nombre des spores est statistiquement le mÃªme Ã lâ€™Ã©chelle des zone agroÃ©cologique. Les frÃ©quences de mycorhization des cacaoyers sont gÃ©nÃ©ralement Ã©levÃ©es et oscillent entre 89,31 % Ã lâ€™Ouest du pays et 92,4 % au Sud-ouest. En revanche, les intensitÃ©s de mycorhization sont infÃ©rieures Ã 25 % dans lâ€™ensemble du verger cacaoyer. Ces rÃ©sultats indiquent que les systÃ¨mes agroforestiers Ã cacaoyer en CÃ´te dâ€™Ivoire abritent une grande diversitÃ© de champignons mycorhiziens Ã arbuscule qui pourrait Ãªtre utilisÃ©e dans diverses initiatives biotechnologiques en agriculture durable. Arbuscular mycorrhizal fungi (AMF) live in symbiosis with plant roots, helping them to absorb the nutrients they need for growth and development. In CÃ´te d’Ivoire, this symbiosis is not considered in cocoa-based agroforestry strategies. The aim of this work is to study the mycorrhizal fungi associated with cocoa trees in agroforestry systems. To this end, cocoa spores and roots from 32 cocoa plantations located in the 4 main agro-ecological zones for cocoa production in CÃ´te d’Ivoire were analysed. The diversity, spore density, mycorrhization rates, species richness and Shannon-Wiener diversity indices of arbuscular mycorrhizal fungi communities were determined. A study of the specific richness and relative abundance of 3271 spores revealed 72 arbuscular mycorrhizal fungi morphotypes in the rhizosphere of cocoa trees in CÃ´te d’Ivoire. On all the sites, 10 families, 17 genera and 49 species of arbuscular mycorrhizal fungi were recorded. Claroideoglomus etunicatum is the dominant species in the cocoa orchard. The abundance of spores in the Ivorian cocoa orchard varied between 7,89 and 17,84 spores. g-1 of soil, with an average of 13,42 spores.g-1 of soil. The number of spores was statistically the same across the agroecological zones. Cocoa mycorrhization frequencies were generally high, ranging from 89,31% in the west of the orchard to 92,4% in the south-west. In contrast, mycorrhization intensities were below 25% throughout the cocoa orchard. These results indicate that cocoa agroforestry systems in CÃ´te d’Ivoire harbour a wide diversity of AMF that could be used in various biotecnological initiatives in sustainable agriculture.