Assessment of the occurrence and richness of arbuscular mycorrhizal fungal spores by direct analysis of field samples and trap culture - a comparative study

Abstract

In this work, we hypothesized that two spore-based methods, direct analysis of field samples and trap cultures, simultaneously used for assessment of occurrence and species richness of arbuscular mycorrhizal fungi (AMF) may vary in their efficiency according to the environmental conditions and the total AMF species richness of the evaluated ecosystem. The performance of both methods was analyzed based on two datasets: 1) a complete site x species matrix compiled from two studies in different land uses in the Amazon using direct analysis of field samples and trap cultures. 2) Total number of AMF morphotypes detected by both methods in published manuscripts across several ecosystems. From dataset 1, direct analysis of field samples revealed 57 morphotypes, whereas only 21 of these were detected by trap culture. Community variation (beta diversity) analysis revealed that field samples are far more sensitive in detecting shifts in AMF community composition among land uses than trap cultures in the Amazon region, with the combined results of both methods being not better than that obtained only by direct analysis of field samples. Analysis of dataset 2 showed that the relative performance of trap cultures, using direct analysis of field sample as reference, was inversely related to the total observed AMF species richness.

Richness of Arbuscular Mycorrhizal Fungi Under Different Agroforestry Practices in the Drylands of Southern Ethiopia

“…This result goes in line with many studies which indicated that high richness of AMF under less disturbed land use systems [70]. This could be different land management conditions causes for such kind of differences in AMF spores between different land use types [94]. The dominance of spores of the genera Acaulospora and Glomus were also reported previously [36,78], this might be both genera have a broad distribution in all kind of agroecosystems [23].…”

Arbuscular Mycorrhizal Fungi from Argentinean Highland Puna Soils Unveiled by Propagule Multiplication

“…Regarding TC, only a low percentage of studies recommended it as a reliable method for AMF multiplication prior to morphological or molecular identification. Some authors argue that TC does not reflect in situ reality [ 19 ]; others [ 20 ] state that TC should not be used to assess AMF diversity whenever the richness is less than 21 species per site, whereas the sole use of direct analysis of field samples should be avoided if the total AMF richness is below that value. However, it was demonstrated [ 21 ] both by morphological and molecular methods that a considerable proportion of spores in the rhizosphere were dead despite their intact appearance.…”

Potential impacts of two types of microplastics on <em>Solanum lycopersicum</em> L. and arbuscular mycorrhizal fungi

“…Despite studies done to explore the effects of MPs on soil's physical and chemical properties, relatively little is known about their biological impacts until recently (Rillig et al, 2019;Horton and Barnes, 2020). Despite certain barriers such as lack of sporulation and parasitism that may lead to a possible underestimation, AMF spore counts provide baseline information to estimate their population in soils (Leal et al, 2017). Therefore, spore counts from field soils are still considered a reliable evidence in comparing AMF populations under different land-use types and treatments (Leal et al, 2017).…”

“…Despite certain barriers such as lack of sporulation and parasitism that may lead to a possible underestimation, AMF spore counts provide baseline information to estimate their population in soils (Leal et al, 2017). Therefore, spore counts from field soils are still considered a reliable evidence in comparing AMF populations under different land-use types and treatments (Leal et al, 2017). According to prior studies, any factors responsible for modifying physicochemical features in soil could eventually mete out harmful impacts on the structural and functional diversity of the soil microbiota (Kaushal and Wani, 2016;Awet et al, 2018;Qi et al, 2018;Rillig and Bonkowski, 2018;Wan et al, 2019;Yi et al, 2020).…”