Morphological and ITS rDNA Sequences Analysis of Pelawan Ectomycorrhizal Edible Mushroom and its Ectomycorrhizal Structure

Abstract

Ectomycorrhizae is the symbiosis of fungi and specific plant which is characterised by miselium mantled on root, the presence of Hartig net, and extracellular hyphae. Some ectomycorrhizal fungi are edible mushroom, and one of edible ectomyorrhizal fungi in Indonesia is pelawan mushroom. Morphological and molecular analysis of pelawan mushroom has been done. The spore shape is ovoid to ellipsoid with completely reticulate ornamentation. The characteristic of macroscopic and microscopic feature, especially spore shape and ornamentation, drew the description to genus Heimioporus which close to H. retisporus but different in its spore morphology and some cystidial features. The DNA isolated using CTAB method and PCR amplified with ITS1 and ITS 4 primers showed about 700 bp long. Molecular analysis based on ITS ribosomal DNA showed this mushroom was closely related to Strobilomyces retisporus, a basidionym of H. retisporus with similarity under 90%. However, the lack of similar ITS sequences of the same genus made it hard to decide the species judgment based on molecular approach. The ectomycorrhizal structure of root symbiont was also examined. The root has crème colour with monopodially branch type and white extra radical septated hyphae without clamp connection. The section of the root revealed the mantle with plectenchymatous and pseudoparenchymatous hyphae and para-epidermal Hartig net. This research revealed a new information about ectomycorrhizal symbiosis between Heimioporus sp. and Tristaniopsis merguensis.