63 research outputs found
Phylogeny of selected <em>Cryptocoryne</em> species in Malaysia based on 5' trnK sequence variation of chloroplast DNA
Molecular systematics of the tropical aquatic plant genus, 'Cryptocoryne' Fischer ex Wydler (Araceae)
Cryptocoryne is an aquatic plant genus occurring in tropical Asia. A number of species within the genus are widely used as foliage plants in tropical fish aquaria. The taxonomy and systematics of the genus have been based in the past on morphological characteristics, geographical distribution and chromosome number. The aim of this research was to construct a phylogeny for the genus based on molecular variation and to establish relationships among species in areas of different geographical origin and of different chromosome base number.
A phylogeny constructed from sequence variation of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA, separated the genus into three distinct clades reflecting a strong geographical pattern. One clade consisted of species from mainland Asia, another was comprised of species from Sri Lanka while the third clade consisted of species from Malesia. However, these clades did not reflect rigidly the geographical origin of areas in which the genus is distributed. The ITS phylogeny also indicated that species with a base chromosome number of
x=14 are derived from x=18 stock, and that x=l1 has arisen twice in the course of the evolution of the genus. The origin of other chromosome base numbers, i.e. x=15 and x=17, was not clearly resolved. A phylogeny based on chloroplast (cp) DNA sequence variation was similar in topology to that of the ITS phylogeny although resolution of species relationships was not so good. Phenograms produced from RAPD variation gave a better resolution of affinities among closely related Cryptocoryne species from Sri Lanka, but differed in overall topology from the phylogenies obtained from ITS and cpDNA sequence variation.
Compelling evidence for the origin of the hybrid C. x willisii from C. walkerii and C. parva was obtained from the RAPD analysis, in that C. x willisii exhibited an additive RAPD profile which combined the profiles of its two putative parents. C. x willisii also contained an ITS sequence
similar to that of C. walkeri in some accessions examined, and a cpDNA
sequence similar to C. walkeri and its close relative C. beckettii
A taxonomic review of yellow Spathoglottis (Orchidaceae) complex in Malaysia
Spathoglottis Blume is a well-known genus with a total of 44 species and widely distributed from Tropical Asia to Subtropical Asia and Pacific Islands; concentrated particularly in the Malesian region. Eight species were recorded from Malaysia and despite of a widely grown genus; Spathoglottis is a taxonomically confused genus in Orchidaceae. Confusion on several species within the Yellow Spathoglottis Complex was resolved using both morphological and molecular evidences
Antimicrobial Activity of Artemisinin and Precursor Derived from In Vitro Plantlets of Artemisia annua L.
Artemisia annua L., a medicinal herb, produces secondary metabolites with antimicrobial property. InMalaysia due to the tropical
hot climate, A. annua could not be planted for production of artemisinin, themain bioactive compound. In this study, the leaves of
three in vitro A. annua L. clones were, extracted and two bioactive compounds, artemisinin and a precursor, were isolated by thin
layer chromatography. These compounds were found to be effective in inhibiting the growth of Gram-positive and Gram-negative
bacteria but not Candida albicans.Their antimicrobial activity was similar to that of antibactericidal antibiotic streptomycin. They
were found to inhibit the growth of the tested microbes at the minimum inhibition concentration of 0.09mg/mL, and toxicity test
using brine shrimp showed that even the low concentration of 0.09mg/mL was very lethal towards the brine shrimps with 100%
mortality rate. This study hence indicated that in vitro cultured plantlets of A. annua can be used as the alternative method for
production of artemisinin and its precursor with antimicrobial activities
Morphological Systematics of Spathoglottis Blume (Orchidaceae: Collabieae) in Peninsular Malaysia and Borneo
Seventy-two morphological characters and three ecological characteristics were measured to assess variation and phylogenetic relationships among twelve species and three infraspecific taxa of the genus Spathoglottis from Peninsular Malaysia and Borneo. The morphological analyses divided Spathoglottis into two main groups based on the colours of the flower: Purple-Flowered Spathoglottis and Yellow-Flowered Spathoglottis. Species within the two groupings were further classified based on the size of the plants (Large/Dwarf Purple Spathoglottis and Large/Dwarf Yellow Spathoglottis) and the shapes of the labellum (spathulate, bilobulate or narrow/thread–like). The selected morphological characters appeared to support the taxonomic boundaries between two mostly debated taxa in the genus, S. aurea and S. microchilina
Studies on Hanguana (Commelinales, Hanguanaceae) for Sunda II: Five new forest species from Peninsular Malaysia and recircumscription of Hanguana malayana
Field work in Peninsular Malaysia as part of the first author's research into relationships and evolutionary polarity between Hanguana malayana, a widespread freshwater helophyte, and the numerous and mostly undescribed Sundaic forest species has to date resulted in the collection of five distinctive novel forest-dwelling Hanguana species. These are described here and figured in colour. Increased understanding of these and other forest species of Hanguana has enabled a concise delimitation of the taxonomically long-obfuscated colonial helophytic H. malayana, and this is here presented, and the species figured. The current taxonomy of Hanguana is summarised, and a key to the so-far described Peninsular Malaysian species is provided
ISSUES IN BIOTECHNOLOGY TEACHING - A nationwide biotechnology outreach and awareness program for Malaysian high schools
Biotechnology education in developing nations remains one of the rate
limiting factors in achieving optimal human resource capacity to drive
and tap the bio-resources of these nations. Many developing countries
are situated within rich bio-diversity enclaves. Biotechnology offers
the promise of tapping these bio resources towards due process of
developing these nations. While there may be a steady stream of biology
and biotechnology based graduates, from Malaysian as well as foreign
universities contributing to the human resource base for these
countries, the numbers and knowledge diversity produced, still lack the
capacity to optimally power research and development as well as supply
the industrial biotechnology sectors of these countries. Realizing the
need to address these issues at the grassroots level of higher
education, Malaysia has taken an active step of bringing biotechnology
into the classrooms of high schools throughout the country. These
future generations of Malaysians, are hoped to progress towards manning
and driving Malaysia's BioValley initiatives (a biotech based R&D
and industry cluster), towards the national dream of developed nation
status by the year 2020, using biotechnology as an economic growth
vehicle. Here, we share our experiences in developing and proliferating
a biotechnology awareness program for Malaysian high schools. It is
hoped that similar programs will strive towards similar objectives in
other developing countries
Comparative Transcriptome Analysis Identifies Potentially Relevant Genes in Rubber Clones with a High Latex Yield (Hevea brasiliensis)
Since the 1950s, the rubber tree (Hevea brasiliensis) has significantly contributed to Malaysia's agricultural economy due to its capability to produce high-value natural rubber. Due to the presence of cis-1,4-polyisoprene, natural rubber exhibits unique properties such as flexibility, high elasticity, and efficient heat dispersion. Cis-1,4-polyisoprene is synthesized via two distinct metabolic pathways: the isoprenoid and rubber biosynthesis. RNA sequencing was performed on 12 specimens from the bark, leaf, and latex tissues of two rubber clones, RRIM 3001 (high latex yield) and RRIM 712 (low latex yield). After quality assessment, these specimens generated a mean of 73,816,244 clean reads. The differential expression analysis revealed that the Acetyl-CoA-Acetyltransferase (AACT) and Diphosphomevalonate Decarboxylase (MVD) genes (via the MVA pathway), as well as the Small Rubber Particle Protein (SRPP) and Rubber Elongation Factor (REF) genes (via the rubber biosynthesis pathway), were overexpressed in the bark, leaf, and latex tissues of RRIM 3001 compared to RRIM 712. The transcription factor Ethylene Response Factor (ERF) was also found to be more highly expressed in RRIM 3001 than in RRIM 712. Five rubber clones with random yield characteristics were used in quantitative amplification analysis to validate AACT, MVD, SRPP, REF, and ERF genes. The quantitative analysis shows that the five genes were consistently expressed with the yield characteristics of the five random rubber clones
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