Sporulation and diversity of arbuscular mycorrhizal fungi in Brazil Pine in the field and in the greenhouse

Abstract

The aim of this work was to assess the sporulation and diversity of arbuscular mycorrhizal fungi (AMF) at different forest sites with Araucaria angustifolia (Bert.) O. Ktze. (Brazil Pine). In addition, a greenhouse experiment was carried out to test the use of traditional trap plants (maize + peanut) or A. angustifolia to estimate the diversity of AMF at each site. Soil samples were taken in two State Parks at southwestern Brazil: Campos do Jordão (Parque Estadual de Campos do Jordão [PECJ]) and Apiaí (Parque Estadual Turístico do Alto Ribeira [PETAR]), São Paulo State, in sites of either native or replanted forest. In PECJ, an extra site of replanted forest that was impacted by accidental fire and is now in a state of recuperation was also sampled. The spore densities and their morphological identification were compiled at each site. In the greenhouse, soil samples from each site were used as inoculum to promote spore multiplication on maize + peanut or A. angustifolia grown on a sandy, low-fertility substrate. Plants were harvested, respectively, after 4 months or 1 year of growth and assessed for mycorrhizal root colonization. Spore counts and identification were also performed in the substrate, after the harvest of plants. Twenty-five taxa were identified considering all sites. Species richness and diversity were greater in native forest areas, being Acaulospora, the genus with the most species. Differences in number of spores, diversity, and richness were found at the different sites of each State Park. Differences were also found when maize + peanut or A. angustifolia were used as trap plants. The traditional methodology using trap plants seems to underestimate the diversity of the AMF. The use of A. angustifolia as trap plant showed similar species richness to the field in PECJ, but the identified species were not necessarily the same. Nevertheless, for PETAR, both A. angustifolia and maize + peanut underestimated the species richness. Because the AMF sporulation can be affected by many conditions, it is impossible to draw detailed conclusions from this kind of survey. More precise experiments have to be set up to isolate the different factors that modulate the ecophysiological interactions between host plant and endophyte.

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

“…Recently, Moreira et al (2007b) found a total of 25 taxa in a survey of three A. angustifolia ecosystems in the State of São Paulo. Also, in all the before-mentioned studies, Acaulospora and Glomus were the genera with the greatest number of species.…”

“…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).…”

Arbuscular mycorrhizal fungal communities in native and in replanted Araucaria forest

“…There are fungi that sporulate more, while others sporulate less, and others yet, do not sporulate or do so only during certain periods of the year (Table 1). Repeated sampling several times during the year could provide a more complete picture of this variability, as discussed in Moreira et al (2007b). Different AMF may have different carbon and other nutrient requirements for sporulation, and this may explain differing AMF phenologies (Violi et al, 2008).…”

Fungos micorrízicos arbusculares nativos e doses de fósforo no desenvolvimento do amendoim RUNNER IAC 886

“…Vários resultados demonstram que a colonização micorrízica e a eficiência micorrízica aumentam com adição de baixos teores de P (MOREIRA et al, 2007;MOREIRA-SOUZA;CARDOSO, 2002), ou pode ser reduzida em altos teores de P (SENA et al, 2004). Assim como o desenvolvimento das plantas também podem ser afetado pelo teor P no solo (COSTA et al, 2005).…”