Phylogenetic Relationships of Ganoderma Species Based on Mitochondrial and Nuclear Dna Sequences from Tamil Nadu, India

Phylogenetic relationship of Ganoderma species confining to Tamil Nadu was assessed by three molecular markers viz., internal transcribed spacer region (ITS) 1 and 2, β-tubulin and ATP synthase subunit 6 (atp6). Forty-three isolates representing 11 species of Ganoderma were identified from ITS rDNA sequence data. The nucleotide variations found in the ITS region were suitable for discriminating the eleven species viz., G. australe, G. cupreum, G. lucidum, G. resinaceum, G. tropicum, G. weberianum, Ganoderma sp. 1, Ganoderma sp. 2, Ganoderma sp. 3, Ganoderma sp. 4 and Ganoderma sp. 5. The terminal clade represent that species and/or species complex were consistent with geographical origin of the isolates and cultural characters. The β-tubulin gene phylogeny provided more robust phylogenetic information for separating ten Ganoderma spp. than the ITS region and found to be suitable in identifying the Ganoderma species and/or species complex. The atp6 gene sequence data acquired highest phylogenetic informative character than nuclear DNA genes; however, due to the very low levels of nucleotide divergence, the gene is suitable at genus or lower level. Ganoderma spp. inferred from these three un-linked loci resulted in a robust phylogeny. The terminal clades of nuclear DNA genes represented the species or species complex and consistent with cultural characteristic, host relationship and biogeographical distribution rather than atp6. This study implies that the higher variability in the nucleotide sequences of the nuclear DNA genes have the potential to be the robust markers for molecular identification than atp6. Chlamydospores in culture provided valuable information in identifying Ganoderma spp.