Occurrence and species richness of mycorrhizal fungi in soil under different land use

Abstract

This study aimed to assess the impact of different land uses on the spore density and richness of arbuscular mycorrhizal fungi (AMF) in a Red Latosol of a tropical savanna biome in Brazil ("Cerrado"). Ten soil samples and roots were obtained from a riparian forest, a pasture, an annual crop production system with no tillage, and a coffee plantation in dry and wet seasons. Spores were extracted, counted, and identified from field soils, and roots were stained to assess mycorrhizal colonization. A total of 42 AMF species were detected in all four land uses. The genus Acaulospora had the largest number of species (18), followed by Glomus (6) and Gigaspora (5). Gigaspora decipiens and Gigaspora margarita were present in all areas, regardless of the sample period. Gigaspora decipiens was the species most frequently recovered and contributed to the majority of spores in coffee plantations and riparian forest. Cetraspora pellucida was dominant in the area of no tillage and Acaulospora tuberculata in the pasture. Low species richness was detected in soils under the coffee plantation, with AMF communities dominated almost exclusively by members of Gigasporaceae. We conclude that the area under the coffee plantation caused a reduction in the richness of AMF species and promoted a dominance of a single family AMF compared with the pasture area.Key words: riparian forest, land use, mycorrhizal colonization, coffee, pasture, no tillage.Résumé : Cette étude devait évaluer l'impact de différentes vocations des terres sur la densité des spores et la richesse des mycorhizes à arbuscules (MA) dans un latosol rouge du biome de la savane tropicale brésilienne (« Cerrado »). Les auteurs ont prélevé dix échantillons du sol et des racines d'une forêt riveraine, d'un pâturage, d'une culture annuelle sans travail du sol et d'une plantation de café à la saison sèche et à la saison humide. Ils ont extrait les spores du sol, puis les ont comptées et identifiées, et ont coloré les racines afin d'en évaluer la colonisation par les mycorhizes. En tout, 42 espèces de MA ont été décelées dans les quatre régimes d'exploitation des terres. Le genre Acaulospora comptait le plus grand nombre d'espèces (18), suivi des genres Glomus (6) et Gigaspora (5). Gigaspora decipiens et Gigaspora margarita ont été observés à tous les sites, peu importe le moment où les échantillons ont été prélevés. Gigaspora decipiens a été l'espèce la plus fréquemment retrouvée, et elle explique la majeure partie des spores identifiées dans la plantation de café et la forêt riveraine. Cetraspora pellucida dominait dans la culture sans travail du sol, tandis qu'Acaulospora tuberculata prévalait dans le pâturage. Les espèces étaient peu diversifiées dans le sol sous la plantation de café, les populations de MA se composant presque exclusivement de membres des Gigasporaceae. Les auteurs en concluent que la plantation de café For personal use only.réduit la diversité des espèces de MA et favorise la domination d'une seule famille, comparativement à la situation observ...

Arbuscular mycorrhizal fungal communities in an iron mining area and its surroundings: Inoculum potential, density, and diversity of spores related to soil properties

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Spore diversity of arbuscular mycorrhizal fungi in human‐modified neotropical ecosystems

“…Our findings confirm that in humid tropical areas the AMF spore species (Aidar et al, ; Picone, ; Zangaro et al, ) and mycorrhized roots (Muthukumar et al, ; Siqueira & Saggin‐Júnior, ; Treseder & Cross, ) tend to be associated with vegetation type and soil fertility as has been found in other studies performed in the tropics. Undoubtedly, this scenario displayed by the spores could not be the same as the colonized roots, which could harbor not sporulated species; however, the morphological approach brings valid and quick results about the communities of AMF (Fernandes et al, ; Landis, Gargas, & Givnish, ).…”

High rates of agricultural gypsum affect the arbuscular mycorrhiza fungal community and coffee yield

“…Arbuscular mycorrhizal fungi inventories in coffee-growing areas of southeastern Brazil, Colombia and Venezuela showed widespread occurrence of species of the genus Acaulospora, followed by Glomus (Saggin Júnior and Siqueira 1996;Cogo et al 2017). Species of the genus Glomus and Acaulospora (Arias et al 2012;Fernandes et al 2016) are usually predominant in coffee plantations; thus, dominance of species of the genus Gigaspora in coffee fields has not been frequently reported. In a previous study conducted in a greenhouse, the species Gigaspora margarita was found to be one of the most efficient in promoting growth and nutrition of coffee trees (Saggin Júnior and Siqueira 1996).…”