1,720,969 research outputs found
Shoot Generation and Callus Induction of Dioscorea hispida Dennst by Different Plant Growth Hormones and Basal Media
No full textDioscorea hispida Dennst produces tuber which possess valuable medicinal properties but unsustainable harvesting has led to its reduction. The plant propagates slowly because of its low tuber sprouting rate. In average, Dioscorea hispida Dennst tubers took approximately 60 d to break dormancy and sprout. Hence, callus culture is proposed as a possible efficient type of culture for manipulation of this species. In the present study, calli were induced from stem segments to evaluate callus culture potential of Dioscorea hispida Dennst. Results indicate that the combination of 1 mgL-1 naphthaleneacetic acid (NAA), 1 mgL-1 6- benzylaminopurine (BAP) and 0.5 mgL-1 2,4-dichlorophenoxyacetic acid (2, 4-D) in Gamborg (B5) medium improved callus multiplication and differentiation in the stem culture as opposed to those in Murashige and Skoog (MS) medium. The findings from the present study provide the basis of callus culture protocol for stem explant of Dioscorea hispida Dennst with B5 being the more effective basal medium
Correlation of scopoletin-induced fluorescence with visible PPD symptoms in greenhouse cassava
No full textPost-harvest physiological deterioration (PPD) is spoilage of cassava storage roots characterized by browning
of parenchyma tissue and vascular streaking. A striking feature of PPD is an accumulation of hydroxycoumarins, such as
scopoletin, scopolin, esculetin and esculin, which are products of phenylpropanoid pathway. PPD, which renders the roots
unpalatable and unmarketable, leads to significant yield loss in global cassava production. Extensive studies have been
conducted to understand the biochemical activities and pathways involved in PPD in which the result requires an
evaluation of PPD symptoms which is usually based on a visual scoring system. However, high variations are consistently
observed between biological replicates making analysis difficult. Therefore, there is urgent need to find a reliable marker
since the generation of reliable data that can be shared or compared between institutions is desirable. The use of
scopoletin-induced fluorescence as a PPD marker was tested in greenhouse-grown cassava storage roots by comparing
fluorescence measurements and the PPD scores generated from normal light photographs of the harvested roots. It was
found that all freshly harvested root samples lacked fluorescent but after 24 hours they dramatically fluoresced to a high
level. However, the occurrence of intense fluorescence was not accompanied by intense PPD symptoms as fluorescence
level declined when visible PPD symptoms developed. Hence, the use of fluorescence or scopoletin as an alternative
marker for PPD remain unconvincing, mainly because it did not parallel with PPD symptom accumulation observed
A Review of Medicinal Plants and Daily Foods used in Southeast Asia Possessing Antidiabetic Activity
Get PDFAccording to the recent estimates by the World Health Organization (WHO), 422 million adults aged over 18 years were living with diabetes in 2014 globally. Surprising, about 1.6 million deaths was reported cause directed by diabetes in 2016. In Southeast Asia alone, 96 million people have diabetes, and this is predicted to increase. The incidence of diabetes is worryingly increasing especially in developing countries. Numerous synthetic drugs have been discovered to control this disease, but these drugs can lead to negative side effects. Therefore, people are looking for natural remedies to combat the disease. The objective of this review is to study of the medicinal plants and daily foods that have been used to treat diabetes. Instead of common traditional medicinal plants such as Andrographis paniculata, Averrhoa bilimbi, Camellia sinensis, Cosmos caudatus Kunth, Leucaena leucocephala, Momordica charantia, Ocimum sanctum, Orthosiphon stamineus, Panax ginseng and Pereskia bleo and; daily foods ingredients like fenugreek, garlic, ginger, onion and turmeric possess significant positive effects on diabetic patients. Antioxidants, for instance andrographolide, flavonoids glycosides like epicatechin, quercetin, catechin, myricetin, epigallocatechin gallate, polysaccharide compound galactomannan, saponin, gingerol, allicin, euganol and curcuma, dietary fibers and some minerals such as magnesium as well as amino acid such as 4-hydroxyisoleucine were found to be responsible for this effect. Although some responsible compounds are known, the mechanisms involved are not yet fully explored. Thus, further research on the mechanism, effective dosage and toxicity of the particular medicinal plants need to be comprehensively studied before they can be marketed as nutraceutical products.Â
Determination of Nitrogen Fixing Capacity of Bacteria Isolated from the Rhizosphere of Acacia Mangium from the BRIS Soil of Tembila, Besut, Terengganu, Malaysia
No full textThe present study was conducted to isolate beneficial bacteria with nitrogen fixing potential from the rhizosphere of Acacia mangium plant. The plant grows wildly on the untouched area of problematic BRIS soil in Tembila, Terengganu. A total of 24 bacterial isolates were successfully sequestered from the soil samples using the Burk’s nitrogen free medium. Based on the preliminary morphology screening, eight bacterial isolates were selected and their morphological and biochemical characteristics were recorded. Three bacterial isolates namely UA1, UA6 and UAA2 were selected as final species for antibiotic sensitivity test and Acetylene Reduction Assay (ARA). All three bacterial isolates showed a high amount of nitrogenase activity in ARA with UA6 produced the highest and significant amount of ethylene with 18.55 nmolC2H4mL-1h-1. UA1 and UAA2 showed almost similar amount of ethylene with 17.10 and 17.00 nmolC2H4mL-1h-1 respectively. The isolated bacteria characteristics through all the test showed that these bacteria have potential to be explore for biofertilizer production industry
α-glucosidase Inhibition, DPPH Scavenging activities and Chemical Analysis of Polysaccharide Extracts from Aquilaria sp. Leaves
No full textAquilaria sp. belongs to Thymelaeaceae family. This genus produces a unique fragrant wood locally known as
‘gaharu’. It is well known for usages in aromatherapy while very few scientific evidence on its usage as herbal
medicine have been published. The current study was therefore conducted to determine the chemical
characteristics as well as antioxidant and α-glucosidase inhibition potential of carbohydrate-rich extracts
(aqueous and polysaccharide extracts) from three Aquilaria species leaves (A. malaccensis, A. sinensis and A.
subintegra). The isolation of polysaccharide (PS) from the aqueous extract (AE) was conducted by ethanol
precipitation prior to ultrasonic-assisted extraction. The total phenolic content (TPC), proximate and Fourier
Transform Infrared Spectroscopy (FTIR) analysis were carried out to investigate the chemical characteristics,
while the bioactivities determined were 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and αglucosidase inhibition. As a result, AE of A. malaccensis leaves showed the strongest α-glucosidase (IC50: 0.038
mg/mL) and DPPH (IC50: 0.084 mg/mL) inhibition while contained more TPC (61.16 mg GAE/g) compared
to other two species. Furthermore, PS of A. malaccensis leaves displayed even stronger α-glucosidase inhibition
(IC50: 0.014 mg/mL) compared to its respective AE and other PS. In conclusion, this study primarily revealed
the scientific evidence on the bioactive potential of PS of Aquilaria sp
Genetic diversity and differentiation of Aquilaria malaccensis Lam. Using RAPD markers
No full textAquilaria malaccensis Lam. (family Thymelaeaceae) commonly known as agarwood or gaharu
producing tree in Malaysia. The tree is being heavily exploited due to its highly valuable agar oil used in
the production of high grade perfumes and traditional medicines. Consequently, their population in
nature is threatened greatly. Conservation of this tree species is of the main concern, however,
identification of A. malaccensis from other Aquilaria sp. based on morphology is very difficult and time
consuming. This study aimed to determine the genetic diversity among three selected Aquilaria sp.
namely A. malaccensis, A. sinensis (Lour.) Spreng. And A. subintegra Ding Hou using random amplified
polymorphic DNA (RAPD) markers and to differentiate A. malaccensis from A. sinensis and A.
subintegra. Out of ten RAPD primers, four primers (G12, R15, U13 and OPA 05) produced the most
clear and reproducible bands. A total of 24 bands were scored from the four primers. Construction of
dendrogram resulted in two major clusters; cluster I consisted of only A. malaccensis accessions, and
cluster II consisted of A. subintegra and A. sinensis accessions. This indicates that A. subintegra is more
closely related to A. sinensis while A. malaccensis is genetically distant from both. Species-specific
bands for A. malaccensis were produced at 875, 1000 and 2500 bp by G12 primer, and at 2500 bp by
OPA 05 primer. This study laid the foundation for a creation of rapid and cost effective molecular
identification of A. malaccensis
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Bacterial identification process using bactfinder© mobile application
No full textBactFinder© is an interactive and mobile application built to facilitate bacteria
identification. As widely known, bacteria are composed of large domains of
prokaryotic microorganisms which are various in types, hence the identification
of these bacterial groups requires a systematic and orderly identification process.
Through this mobile app, experimental results from biochemical and bacterial
morphological tests carried out in the laboratory before hand must be submitted
to the application before bacterial identification can be performed. Previously,
academics user and students have to refer to many references such as research
books and related academic journals in order to finalise their bacteria
identification. This process, of course, will take relatively longer time and less
effective. This BactFinder© mobile application is equipped with a database of
19 types of biochemical tests including bacteria morphology. The database was
built based on Bergey’s Manual of Systematic Bacteriology, Bergey’s Manual of
Determinative Bacteriology and other related scientific journals. The BactFinder©
mobile app has been proved able to provide fast (± 2 seconds) and precise
responses in helping students and academics user in the process of identifying
bacteria species in the lab. This application is also suitable for undergraduate,
post-graduate and academicians in the field of microbiology, biotechnology and
science in general
Detection of somaclonal variation in aquatic plant pearl grass (Hemianthus micranthemoides)
No full textHemianthus micranthemoides is an ornamental plan used for foreground plant in aquarium decorations. In Malaysia,
the plant available on market is regenerated through tissue culture techniques which expose the risk for
somaclonal variation. The objectives of this study are to identify suitable Random Amplified Polymorphic
DNA (RAPD) markers for determining somaclonal variation rate in micropropagated plantlets of H.
micranthemoides and to observe the effects of somaclonal variation on the plantlet growth (area of spreadability,
shoot and root length). Out of 20 RAPD primers screened by polymerase chain reaction (PCR) using mother
plant, one was selected as a suitable marker to detect somaclonal variation of H. micranthemoides which was P15.
Somaclonal variation rate of the H. micranthemoides was determined by analyzing the RAPD-PCR bands. The
results showed somaclonal variation was observed at the fifth subculture (S5) with the percentage of
polymorphic bands of 50 % when compared to mother plant. Repeated subclutures has affected the growth of
the regenerates negatively. It was shown that as the number of subculture increased, the growth of plantlet
decreased in terms of decreasing shoot and root length as well as area of spreadability. This findings serves as a
guide especially for tissue culturist to minimize subculture numbers when micropropagating H. micranthemoides
- …
