Seasonal dynamics of arbuscular mycorrhizal fungi in plants of Theobroma grandiflorum Schum and Paullinia cupana Mart. of aN agroforestry system in Central Amazonia, Amazonas State, Brazil

Abstract

The seasonal dynamics of Arbuscular Mycorrhizal Fungi (AMF) was investigated in the rhizosphere of two fruit species in a terra firme (upland) ecosystem in Central Amazonia. Two host species (Theobroma grandiflorum and Paullinia cupana) and nine sampling months (August, September and December/1998, February, April, May and December/1999, February and May/2000 were studied in a completely randomized design, with five replications, set in a 2 x 9 factorial experiment. Soil (0-20 cm depth) and root samples were collected between August 1998 and May 2000. The mean percent colonization of AMF for both species reached maximal values in February and May 2000 (rainy season). In April and May 1999, February and May 2000 (rainy season) the highest AMF spore numbers were registered. The pluvial precipitation was significantly positively correlated with AMF number spores for both fruit species, and significant positive correlation only with AMF colonization of P. cupana. Soil moisture content was positively correlated with colonization and spore numbers of AMF for both species evaluated. AMF colonization and AMF spore numbers of T. grandiflorum were positively correlated with soil Mg and K concentrations. AMF spore numbers of T. grandiflorum were also negatively correlated with effective cation exchange capacity (ECEC). AMF colonization and AMF spore numbers in the rhizosphere of P. cupana were positively correlated with pH and Mn concentrations. AMF colonization was also positively correlated with AMF spore numbers for both species evaluated. In conclusion, this study showed that AMF colonization and sporulation are seasonal and dependent on host plant species, pluvial precipitation, soil moisture content and soil chemistry in Central Amazonia conditions.

Influence of edapho-climatic factors on the sporulation and colonization of arbuscular mycorrhizal fungi in two Amazonian native fruit species

“…The positive correlation between the precipitation and AMF variables in the present study were opposite to the previous finding that mycorrhizal variables and rainfall had a negative correlation (Muthukumar and Udaiyan, 2002), but consisted with other studies (Braunberger et al, 1994;Lingfei et al, 2005). Soil moisture has been reported to be positively correlated with AMF colonization (He et al, 2002;Bohrer et al, 2004;Lingfei et al, 2005, Oliveira andOliveira, 2005), which might be a strong argument supporting the present results, as precipitation is an important element of soil moisture. Negative correlations between the evaporation and AMF variables also reinforced these data.…”

Soil and seasons affect arbuscular mycorrhizal fungi associated with Tamarix rhizosphere in arid and semi-arid steppes

“…Both authors suggested that AMF colonization might be influenced by environmental data, soil chemical composition and variability of the site, in addition to root architecture, inoculum potential and seasonal variation. This variation in AMF root colonization according to sites was previously reported by some authors in different ecosystems such as Alpine prairies (Ruotsalainen et al, 2002), sand dunes in arid areas (Jaiti et al, 2007;Bouamri et al, 2014) and Amazonian agroforestry system (Oliveira and Oliveira, 2005). Interestingly, our results demonstrated that combination of soil parameters and seasonal variation has significant effects on mycorrhizal root colonization.…”

Specific Variations of Arbuscular Mycorrhizal (AM) Fungi in Potential Timber Yielding Tree Species From the Western Ghat Region of Goa, India

“…Thus, the results of this investigation give some support to a strong influence of edaphic factors, such as pH on symbiotic association in the acid soils and nutrient-limited soils of the Western Ghat region of Goa. The present study was carried out in the dry season and it is suggested that the duration of moisture availability determines the level of AMF colonization which especially leads to improvement of soil fertility, especially the increase of pH and provides favorable environment for mycorrhizal formation and function (de Oliveira & de Oliveira, 2005). In absence of these conditions, the pH is acidic and limits the AM fungal formation.…”