Molecular analysis of Ganoderma and Amauroderma species in the tropical rainforest of Sarawak, Borneo

<p>This study aimed to record the genetic types of both <em>Ganoderma</em> <em>australe</em> sensu lato and <em>Amauroderma</em> <em>subrugosum</em> sensu lato with their morphological and ecological traits. <em>Ganoderma</em> <em>australe</em> sensu lato and <em>Amauroderma</em> <em>subrugosum</em> sensu lato were studied in three national parks in Sarawak: Santubong, Kubah (western area) and Lambir Hill (northeastern area). The decay stage and diameter of fallen logs from which fungal fruiting bodies appeared were recorded. The size of the pores and length of the tube of fruiting bodies were measured and recorded in the laboratory. Molecular phylogenetic trees were inferred from nucleotide sequence of the internal transcribed spacer (ITS) region of ribosomal RNA. In the phylogenetic tree analysis, <em>Amauroderma</em> <em>subrugosum</em> was grouped into a single genetic type while Ganoderma australe has been divided and classified into four genetic types: type 1, type 2, type 3, and type 5. All genetic types of <em>Ganoderma</em> <em>australe</em> fruiting bodies frequently appear in the intermediate stages of decayed wood (stage 3) from small and medium-sized (diameter) fallen trees or logs. In this study, no novel genetic types of <em>Ganoderma</em> <em>australe</em> were observed, and several genetic types were not observed in <em>Amauroderma</em> <em>subrugosum</em>. All genetic types of <em>Ganoderma</em> <em>australe</em> were found in the northeast (Lambir Hills) and west (Kubah, Santubong) areas of Sarawak. This suggests that these genetic types are widely distributed across Sarawak. Further study is needed to reveal the mechanisms that drive speciation and maintain genetic diversity in <em>Ganoderma</em> <em>australe</em> and the mechanisms that prevent speciation in <em>Amauroderma</em> <em>subrugosum</em>.</p>