Avaliacao da eficiencia simbiótica de fungos endomicorrizicos para o cafeeiro
The symbiotic effectiveness (SE) of several endomycorrhizal fungi on coffee, was evaluated using a new method. For the SE assessment, coffee seedlings were inoculated with different arbuscular mycorrhizal fungi (AMF) and allowed to grow in a low fertility non-fumigated soil amended with increasing levels of soluble phosphate, for 170 days. Seedlings were transplanted to field-soil containing indigenous AMF and inoculated with spore suspension of Gigaspora margarita, Glomus clarum and four isolates of Glomus etunicatum native from Lavras (Lav), Patrocinio (Pat), Varginha (Var), and Tres Pontas (TP). Seedlings grown in fumigated (Fum) or non fumigated field soil (Ni) were used as control. Mycorrhizal and phosphorus benefits were estimated by the integrated area of the response curves for several plant variables, and the SE was evaluated based upon the proporcional percentual area of mycorrhizal benefit in relation to phosphorus benefit. SE values varied with plant age and with response variable. Based upon mean SE value for several variables, G. margarita and G. etunicatum-Pat was categorized as "high SE", G. etunicarum-Lav and TP as "moderate SE"; and G. clarum, G. etunicatum-Var and the indigenous AMF fungi were classified as "low SE". The inoculation potential (IP) of each fungus was also estimated, based upon their mycorrhizal benefit over plants colonized by indigenous AMF fungi. IP values increased linearly with fungal tolerance to soil P, thus indicating that SE is related to fungal adaptation to edaphic conditions. The proposed method is advantageous because it considers mycorrhizal fungal benefits over a wide range of soil phosphorus and allows a quantitative assessment of AMF benefits to the host plant.
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| Format: | biblioteca |
| Published: |
1995
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| Subjects: | COFFEA ARABICA, GLOMUS ETUNICATUM, GIGASPORA MARGARITA, GLOMUS CLARUM, INOCULACION, FLORA MICROBIANA, SUELO, HONGOS, SIMBIOSIS, MYCORRHIZAE, SEMILLERO, TRASPLANTE, |
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