In Vivo And In Situ Cultivation And Distribution Of Selected Tropical Lichens In Northern Peninsula Malaysia

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Date
2016-10
Authors
Lim, Choon Leng
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Publisher
Universiti Sains Malaysia
Abstract
In Malaysia, the diversity of tropical rainforests is well established for animal and plant species but limited for cryptogams, especially fungal groups and their lichenised counterparts, hence there are still enormous gaps in fundamental researches, taxonomical and ecological knowledge. However, very few tropical lichens were studied and identified, and no study has been done on the in vivo/in situ culture of lichens on artificial substrate, cotton shirt cloth. In the present study, selected lichen specimens collected from reserved forests in Ceruk Tuk Kon, Bukit Mertajam and Taman Rimba Teluk Bahang, Pulau Pinang were identified morphologically using the internal transcribed spacer (ITS) regions of fungal ribosomal DNA (rDNA). A total of 20 lichen specimens were randomly collected, which covered two major classes of Lecanoromycetes (95%) and Dothideomycetes (5%). All specimens were identified up to genus level based on morphological characteristics, representing 14 genera, 8 families and 4 orders. Molecular identification based on ITS region using ITS1-F and ITS4 primers set were mostly corresponded with morphological characteristics described in those identification keys used. Six out of seven ITS region sequences search against GenBank/NCBI and the BOLD Systems fungal databases were assumed being identified up to closely species levels, or related congeneric species-group, where the sequences similarities were < 99%. However, two non-lichenised forming fungi were amplified using the ITS1-F and ITS4 primers set, namely Trichoderma atroviride and Hypocrea atroviridis resulted of non-target lichen fungal species. In vivo/in situ cultivation of fragmented vegetative thalli of Dirinaria picta was established on cotton shirt cloth. Early growth phase started forming a single tiny thallus, subsequently juvenile thallus started to develop into elongated lobe, but did not has uniform lobe’s shape during the first 28 months. On the 20th month onwards, at least some newly lobes were developed to form marginal lobes, radial growth pattern was fully being observed, and more and more juvenile lobes were developed. This method for in vivo/in situ axenic cultivation of D. picta should facilitate future research on this ecological and biological important lichen species. In conclusion, molecular data of ITS regions based on lichen-forming fungal markers combined with generic keys of morphological characteristics provide valuable approach for species identification. This study also provided fundamental groundwork in the methodological application of axenic culture of foliose lichen, D. picta in natural climatic conditions as well as potential research of culture-independent approaches of lichen as biological indicator in future.
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Keywords
Distribution of selected tropical Lichens , in northern peninsula Malaysia
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