Morphological spore-based characterisation and molecular approaches reveal comparable patterns in glomeromycotan...

Area of Science:

• Ecology
• Mycology
• Soil Science
• Molecular Biology

Background:

• Arbuscular mycorrhizal fungi (AMF) communities have traditionally been characterized by morphological identification of soil spores.
• Molecular methods, like soil metabarcoding targeting the internal transcribed spacer (ITS) region, are increasingly popular but direct comparisons with morphological methods are scarce.
• Previous assumptions suggested molecular methods are consistently superior to morphological identification for AMF community assessment.

Purpose of the Study:

• To compare the efficiency and outcomes of morphological versus molecular methods for characterizing AMF communities in vegetable farm soil samples.
• To systematically review existing literature comparing both methods in agroecosystems.
• To determine if a combined approach is necessary for comprehensive AMF community analysis.

Main Methods:

• Analysis of AMF communities in soil samples from vegetable farms using both traditional morphological spore identification and molecular analysis (ITS metabarcoding).
• Systematic literature search to identify and retrieve nine additional studies that utilized both morphological and molecular approaches on the same soil samples.
• Comparative analysis of the AMF taxa identified by each method within the study's samples and the retrieved literature.

Main Results:

• AMF communities identified by morphological spore-based methods differed from those identified by molecular markers, contrary to frequent claims.
• Morphological methods occasionally revealed higher diversity of glomeromycotan communities and identified taxa missed by molecular methods, and vice versa.
• Both field and literature data indicated that morphological and molecular approaches yield comparable patterns when comparing AMF communities across different environmental conditions.

Conclusions:

• A combination of both morphological and molecular approaches is essential for a comprehensive and exhaustive characterization of AMF communities.
• While distinct, both methods provide valuable, sometimes complementary, information about AMF diversity and composition.
• For comparative studies across environmental gradients, either method can provide reliable community patterns, suggesting a degree of functional equivalence in certain contexts.