Arbuscular mycorrhizal fungi associated with Araucaria angustifolia (Bert.) O. Ktze

Abstract

Specimens of Araucaria angustifolia from a native forest reserve and a reforested area in the State Park of Campos do Jordão were studied to determine the number and diversity of spore populations of arbuscular mycorrhizal fungi (AMF) and root colonization. Six randomly chosen plots (planted with 8- to 12-year-old plants) were delimited, four in the native forest and two in the reforested area. Rhizosphere and root samples were collected during two periods of the year corresponding to the rainy and dry seasons. A greenhouse experiment was set up for multiplication of field propagules (from the native forest and reforested area) for two consecutive generations. Araucaria leaves from the experimental plots were collected during the first sampling for nutrient analysis. Twenty-four AMF taxa were found and percent AM colonization was determined in all plots. Not all AMF species observed in the field were re-isolated through the recovery pot cultures, even after a second cultivation cycle. The foliar nutrient analysis showed higher nutrient levels in plants from the native forest than the reforested area. Generally, spore richness and diversity were highest during the warmer and more humid period and in the native forest plants.

Species richness of arbuscular mycorrhizal fungi in forests with Araucaria in Southern Brazil

“…Although these data might be overestimated, due to the possible inclusion of non-infective and dead spores in the count, the comparison among sites is still valid. In contrast to Moreira-Souza et al (2003) and Moreira et al (2007a), but in agreement with Moreira et al (2006), we found greater spore abundance in the Araucaria reforestation than in the native forest. These contrasting observations are probably related to historical and structural differences between the examined forests.…”

“…Ten years later, Breuninger et al (2000) compared the richness of species between an area of Araucaria forest and an adjacent grassland in the northern highlands of Rio Grande do Sul, and found a two-fold difference in the number of species of AM fungi: 13 in the former and six in the latter. When comparing a native forest with Araucaria and a reforested area with both Araucaria and Pinus in the State of São Paulo, Moreira-Souza et al (2003) found a greater number of AMF spores in the native forest (21 species) than in the reforested area (14 species). Recently, Moreira et al (2007b) found 25 AMF species three Araucaria ecosystems: a native forest (15 species), an Araucaria reforestation (13 species) and a burned Araucaria reforestation (13 species).…”

“…The slow growth rate of Araucaria angustifolia, its common association with AMF (e.g., Oliveira & Ventura 1952, Muchovej et al 1992, Breuninger et al 2000, Moreira-Souza et al 2003, Moreira et al 2006, and its strong growth response to inoculation with AM fungi (Moreira-Souza & Cardoso 2002, Zandavalli et al 2004 suggest that the success of any plantation effort, aiming either the conservation or the sustainable use of the species, might greatly depend on ensuring that the young plants are colonized by the fungal partners.…”

Effects of different management practices on arbuscular mycorrhizal fungal diversity in maize fields by a molecular approach

“…Until now, most surveys described AMF communities present in natural or in agricultural fields using molecular and morphological approaches, on either mycorrhizal roots (Alguacil et al 2009;Verbruggen et al2010) or spores (Moreira-Souza et al 2003;Oehl et al 2003), but just a handful of studies have considered the entire soil, or at least the entire topsoil (Hempel et al 2007;Pivato et al 2007;Cesaro et al 2008).…”

Diversity of Arbuscular Mycorrhizae Fungi from Orchard Ecosystem

“…Wide distribution and a strong capacity of sporulation usually exist concurrently in dominant species [30,31]. But in this study, the dominant species of G.aggregatum, G. fasiculatum, G.mosseae were found to be widely distributed in root samples rather than their abundance in soil.…”