Spore communities of arbuscular mycorrhizal fungi and mycorrhizal associations in different ecosystems, south Australia

Abstract

SUMMARYCommunities of arbuscular mycorrhizal fungi (AMF) were surveyed in different South Australian ecosystems. The soil was wet-sieved for spore extraction, followed by the determination of presence and abundance of AMF species as well as the percentage of root colonization. Mycorrhizal associations were common and there was substantial fungal diversity in different ecosystems. Spores were most abundant in the permanent pasture system and less abundant under continuous wheat. The incidence of mycorrhizal associations in different plant species and the occurrence of Arum-and Paris-type colonization generally conformed with previous information. Spores of seventeen AMF were verified throughout seasonal changes in 1996 and 1997 in the permanent pasture and on four host species (Lolium perenne, Plantago lanceolata, Sorghum sp. and Trifolium subterraneum), set up with the same soils under greenhouse conditions. Glomus mosseae was the dominant spore type at all sampling times and in all trap cultures. Mycorrhizal diversity was significantly affected by different sampling times in trap cultures but not in field-collected soil. P. lanceolata, Sorghum sp. and T. subterraneum as hosts for trap cultures showed no differences in richness and diversity of AMF spores that developed in association with their roots. Abundance and diversity were lowest, however, in association with L. perenne, particularly in December 1996. Results show that the combination of spore identification from field-collected soil and trap cultures is essential to study population and diversity of AMF. The study provides baseline data for ongoing monitoring of mycorrhizal populations using conventional methods and material for the determination of the symbiotic effectiveness of AMF key members.Index terms: trap cultures, Glomus, Gigaspora.

Changes in an Arbuscular Mycorrhizal Fungi Community Along an Environmental Gradient

“…There was a difference in the AMF assembly in the field compared to that observed in the trap cultures. The trap culture represents a microenvironment that provides different conditions and hosts from those found in the field [46], subjecting the AMF to reduced space, in which the taxa are submitted to greater competition. Thus, the AMF can assume other survival strategies and form different types of propagules.…”

Colonização micorrízica, densidade de esporos e diversidade de fungos micorrízicos arbusculares em solo de Cerrado sob plantio direto e convencional

“…Os FMAs causam impactos que vão desde suas relações com plantas (processos de absorção de nutrientes), com comunidades vegetais (influenciando sua diversidade e abundância) e, finalmente, com processos relacionados à estabilidade de ecossistemas, ao participarem de forma ativa e significante na dinâmica do carbono e agregação do solo (BERBARA; SOUZA; FONSECA, 2006). Sendo assim, tornase importante manejar a diversidade da cobertura vegetal para obter populações diversificadas de FMAs, conseguindo-se o máximo potencial das espécies micorrízicas em prol das espécies vegetais (ANTONIOLLI et al, 2002).…”

Alta presencia de cadmio resulta en baja diversidad de hongos formadores de micorrizas arbusculares asociados a cacao (Theobroma cacao L.)

“…Tokio Long White, Fercon®), crecidas en un sustrato con 800 g de una mezcla de suelo:arena 1:1 (p/p) autoclavada tres veces (110 °C, 45 min) y 200 g de la muestra de suelo rizosférico de cacao en materas de plástico de 1 L para el crecimiento de las plantas durante seis meses en los invernaderos del departamento de Biología de la UNAL. Este procedimiento se realizó para obtener esporas en buen estado para facilitar su identificación taxonómica y para identificar morfoespecies que en el momento del muestreo se encontraban en baja frecuencia o como fragmentos de hifas o vesículas presentes en la raíz (Antoniolli et al, 2002).…”

“…3b). Esto podría deberse a que existen diferencias en el tiempo de esporulación entre las especies de HFMA (Antoniolli et al, 2002;Souza et al, 2005) y en la capacidad de multiplicación de las especies hospedero (Del Val et al, 1999). Por estas razones, futuros estudios deberían contemplar el uso de más de una especie de planta trampa, diferentes tiempos de muestreo y otros aspectos que permitan multiplicar la totalidad de la diversidad de esporas presentes en los suelos.…”