Characterization of Arbuscular Mycorrhizal Fungus Communities of <i>Aquilaria crassna</i> and <i>Tectona grandis</i> Roots and Soils in Thailand Plantations

<div><p><i>Aquilaria crassna</i> Pierre ex Lec. and <i>Tectona grandis</i> Linn.f. are sources of resin-suffused agarwood and teak timber, respectively. This study investigated arbuscular mycorrhizal (AM) fungus community structure in roots and rhizosphere soils of <i>A. crassna</i> and <i>T. grandis</i> from plantations in Thailand to understand whether AM fungal communities present in roots and rhizosphere soils vary with host plant species and study sites. Terminal restriction fragment length polymorphism complemented with clone libraries revealed that AM fungal community composition in <i>A. crassna</i> and <i>T. grandis</i> were similar. A total of 38 distinct terminal restriction fragments (TRFs) were found, 31 of which were shared between <i>A. crassna</i> and <i>T. grandis</i>. AM fungal communities in <i>T</i>. <i>grandis</i> samples from different sites were similar, as were those in <i>A. crassna</i>. The estimated average minimum numbers of AM fungal taxa per sample in roots and soils of <i>T. grandis</i> were at least 1.89 vs. 2.55, respectively, and those of <i>A. crassna</i> were 2.85 vs. 2.33 respectively. The TRFs were attributed to Claroideoglomeraceae, Diversisporaceae, Gigasporaceae and Glomeraceae. The Glomeraceae were found to be common in all study sites. Specific AM taxa in roots and soils of <i>T. grandis</i> and <i>A. crassna</i> were not affected by host plant species and sample source (root vs. soil) but affected by collecting site. Future inoculum production and utilization efforts can be directed toward the identified symbiotic associates of these valuable tree species to enhance reforestation efforts.</p>