Keywords :
Lichenized Fungi; Phylogeny; Taxonomy; Tropical Species
บทคัดย่อ :
The crustose lichenized genus Graphis is one of the largest genera of tropical family Graphidaceae. Since Thailand is located in a hot and humid climatic zone, a variety of tropical ecosystems are maintained and hence are able to support a number of Graphis species, but no systematic report of the genus has been completed. The objectives of the present study were to investigate the diversity of genus Graphis in different forest types in Thailand and to examine its relationship with environmental factors. For the systematic study of genus Graphis in Thailand, lichen specimens were randomly sampled in twelve localities (eleven national parks and one research station). The collected lichens were then take the laboratories for identification on the basis of morphological, anatomical, chemical, and molecular studies. Two molecular markers, the mitochondrial small subunit ribosomal (mtSSU) and nuclear large subunit ribosomal (nuLSU) genes, were amplified, sequenced, and then used for phylogenetic analyses with Maximum likelihood and Bayesian approaches. Thirty- two species, six new records, and one new species of the genus Graphis were found in this study. Molecular data, along with morphological and chemical evidence, supported the identity of the new species, Graphis koratensis Pitakpong, Kraichak, Lucking. Keys to species for the examined specimens were constructed, including type, bibliographies, and photographs. Ecologically, Graphis species distributed in many forest types in the altitude range of 150-1,000 meters. Some species were widespread in many habitats, while some are more restricted.
The study of the effect of environmental factors on species richness of lichens family Graphidaceae was conducted at Sakaerat Environmental Research Station. Lichen sampling on tree trunk was conducted on 85 trees by the cluster sampling technique. Ten plots in the dry dipterocarp and dry evergreen forests with size of 20 x 20 square meters were randomly chosen. For the study of host plants, various substrate factors were measured, including circumference of tree, pH of bark, bark crevice depth, and percent moisture. The results found 12 genera and 25 species of Graphidaceous lichens including the genera Carbacanthographis (2 spp.), Diorygma (1 sp.), Dyplolabia (1 sp.), Fissurina (2 spp.), Graphina (1 sp.), Graphis (9 spp.), Hemithecium (2 spp.), Pallidogramme (1 sp.), Phaeographis (3 spp.), Platygramme (1 sp.), Platythecium (1 sp.), and Sarcographa (1 sp.). The highest species richness of lichen species was found on Shorea obtusa and Canarium subulatum about 12 lichen species lichen species. Canonical Correspondence (CCA) showed the most pronounced factor affecting the species richness of Graphidaceous lichens was bark pH.
เอกสารอ้างอิง :
Pitakpong, A., 2015. Diversity and molecular phylogeny of the lichen genus Graphis (Graphidaceae) in Thailand (Doctoral dissertation, School of Environmental Biology Institute of Science Suranaree University of Technology).
