Production of native arbuscular mycorrhizal fungi inoculum under different environmental conditions

AbstractIn order to obtain an arbuscular mycorrhizal fungi (AMF) native inoculum from Sierra de Moa and determine the most appropriate conditions for its big scale production, four light and temperature combinations were tested in three plant species (Calophyllum antillanum, Talipariti elatum and Paspalum notatum). Growth and development parameters, as well as the mycorrhizal functioning of the seedlings were evaluated. The natural light treatment under high temperatures (L-H) was the most suitable for the growth and development of the three plant species, showing the highest total biomass values, mainly of root, and a positive root-shoot ratio balance. This treatment also promoted higher values of root mycorrhizal colonization, external mycelium and AMF spore density. A total of 38 AMF species were identified among the plants and environmental conditions tested. Archaeospora sp.1, Glomus sp.5, Glomus brohultii and G. glomerulatum were observed in all the treatments. The L-H condition can be recommended for native inoculum production, as it promotes a better expression of the AM symbiosis and an elevated production of mycorrhizal propagules

Seleção de fungos micorrízicos arbusculares para Coffea canephora Pierre ex A. Froehner cultivar clonal conilon ‘BRS OURO PRETO’

Coffee production in Brazil expands to warmer regions with Coffea canephora clonal cultivar Conilon ‘BRS Ouro Preto’. The response of ‘BRS Ouro Preto’ to arbuscular mycorrhizal fungi (AMF) inoculation has not been tested. This research aimed to select AMF species capable of promoting growth and phosphate nutrition of this cultivar. Three clones were evaluated (M057, M194 e M199) in three Ultisols, collected in areas under sugarcane (Soil 1), Cerrado (Soil 2) and Atlantic Forest (Soil 3). The inoculation treatments were: Acaulospora colombiana+Glomus sp., Acaulospora scrobiculata, Claroideoglomus etunicatum+Glomus sp., Dentiscutata heterogama, Gigaspora margarita and Rhizophagus clarus, besides two not inoculated controls, one of them with complete fertilization. The first and third soils promoted greater vegetative plant development. The chlorophyll and phosphorus content in leaves was higher in plants of soil 3. The best response to inoculation, expressed through plant growth and nutrition, was verified in soil 1, with the best treatments being C. etunicatum+ Glomus sp. and G. margarita. The species Glomus sp., present in treatments A. colombiana+ Glomus sp. and C. etunicatum+ Glomus sp., exhibited high sporulation and promoted growth and nutrition of ‘BRS Ouro Preto’. Clones M057 and M194 had the highest growth, response to inoculation and AMF sporulation, compared to clone M199. Clones M057 and M194 can, therefore, be considered mycotrophic, and promoters of AMF sporulation, while clone M199 can be classified as poorly mycotrophic.No Brasil a cafeicultura se expande para regiões mais quentes com a cultivar clonal Conilon ‘BRS Ouro Preto’ da espécie C. canephora. A resposta da ‘BRS Ouro Preto’ à inoculação com fungos micorrízicos arbusculares (FMAs) ainda não foi testada. O presente estudo visou selecionar espécies de FMAs promotoras do crescimento e nutrição fosfatada da referida cultivar. Avaliaram-se três clones (M057, M194 e M199) em três Argissolos Vermelho-Amarelos, coletados em áreas sob: cana-de-açúcar (Solo 1), Cerrado (Solo 2) e Mata Atlântica (Solo 3). Os tratamentos de inoculação foram: Acaulospora colombiana+Glomus sp., Acaulospora scrobiculata, Claroideoglomuse tunicatum+Glomus sp., Dentiscutata heterogama, Gigaspora margarita e Rhizophagus clarus, além de duas testemunhas não inoculadas, uma delas com adubação completa. O primeiro e o terceiro solos proporcionaram maior desenvolvimento vegetativo às plantas. O teor de clorofila e fósforo nas folhas foi maior nas plantas do solo 3. A melhor resposta à inoculação, expressa através do crescimento e nutrição das plantas, foi verificada no solo 1, sendo os melhores tratamentos C. etunicatum+ Glomus sp. e G. margarita. A espécie Glomus sp., presente nos tratamentos A. colombiana + Glomus sp. e C. etunicatum+Glomus sp., apresentou alta esporulação e promoveu o crescimento e nutrição da ‘BRS Ouro Preto’. Os clones M057 e M194 apresentaram maior crescimento, resposta à inoculação e esporulação de FMAs, comparados ao clone M199. Assim, os clones M057 e M194 podem ser considerados micotróficos e promotores da esporulação, enquanto o clone M199 caracteriza-se por baixa micotrofia