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
Journal Title
Journal ISSN
Volume Title
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.
Description
Keywords
Distribution of selected tropical Lichens , in northern peninsula Malaysia