Identification of Ectomycorrhizae in Dipterocarp Roots using DNA Metabarcoding in Tropical Urban Parks

Abstract

Ectomycorrhizae (ECM) are important symbionts for multiple host plants. This study used morphology and DNA metabarcoding to identify ECM in Dipterocarpaceae, the dominant tree family of Southeast Asian forests. ECM fruiting bodies were first visually documented and identified across five urban parks in Singapore. Under host Dipterocarp Hopea odorata trees, 50 soil and root samples were collected. This was done together with another 50 root samples taken from ten species of host Dipterocarp seedlings at the Singapore Botanic Gardens’ Plant Resource Centre nursery. Eight genera of ECM were found in parks, one was identified to species level and three genera were only found from fungal Amplicon Sequence Variants (ASVs) using DNA metabarcoding. Although the nursery had more Dipterocarp species, only four genera of ECM were present. ECM communities differed slightly across host species, but not host genera. Tomentella spp. were the most common ECM found in parks and Dipterocarp seedlings.