Tropical life sciences research最新文献

Benthic foraminifera are unicellular marine micro-organism with a hard exoskeleton and commonly present in the benthic community of marine ecosystem. This study aimed to identify the benthic foraminifera present along the coastal areas of eight municipalities in Biliran Island, Philippines. Quadrat sampling was conducted and three samples per quadrant transect of 1 m × 1 m divided into nine squares were collected. The samples were then observed under the microscope, and the specimens seen were identified by comparing them with the images of the sample species from the website https://marinespecies.org/. The researchers conducted an in-situ collection of the foraminiferal shells from intertidal areas along shallow water coastlines of the island. Results showed that the coastal environment of Biliran Island has the presence of the genera Spirillina, Quinqueloculina, Marginopora and Sorites. The identified species were classified based on their feeding mechanisms as herbivory and passive suspension feeding. The presence of benthic foraminifera species along the coastal environments of Biliran Island provides a record of the environment where they are found, making them natural bioindicators of water quality. This study provides a baseline for further studies on the distribution and abundance of benthic foraminifera in the area and can contribute to the understanding of the environmental conditions of the coastal areas in Biliran Island.

The Sunda porcupine (Hystrix javanica, F.Cuvier, 1823) is a rodent-mammal species native to Indonesia and is utilised in traditional medicine for the treatment of various ailments. Some ethnic communities in Indonesia have traditional beliefs regarding Sunda porcupine's quills, which are thought to relieve back pain and toothache. Despite this traditional knowledge, there is limited scientific research on the topic. The aim of this study was to identify active compound in an ethanolic crude extract of Sunda porcupine's quills, and to evaluate its antioxidant and antimicrobial properties. The antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH)-free radical scavenging assay while the antimicrobial activity was evaluated through microdilution resazurin assay. The total phenolic and flavonoid contents were also determined to support the antioxidant properties. The active compounds were identified using gas chromatography-mass spectrophotometer (GCMS) with the National Institute of Standards and Technology (NIST-11) library. The result showed that the extract possesses antioxidant properties (IC₅₀ 138.93 μg/mL) and antimicrobial properties against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Pseudomonas aeruginosa (P. aeruginosa) and Candida albicans (C. albicans) (IC₅₀ range 0.40 mg/mL-33.05 mg/mL). Total phenolic content (TPC) and total flavonoid content (TFC) were 27.29 ± 2.20 mgGAE/g and 27.09 ± 1.66 mgQE/g, respectively. A total of 24 active compounds from the crude extract were identified. As much as five compounds serve as antioxidant agents, including: butylated hydroxytoluene; eicosane; 1-iodo-hexadecane; methyl ester hexadecanoic acid; and L-(+)-ascorbic acid 2,6-dihexadecanoate. Furthermore, as much as 11 compounds serve as antimicrobial agents, including: tetradecane; pentadecane; 2-isopropyl-5-methyl-1-heptanol; hexadecane; butylated hydroxytoluene; eicosane; 1-iodo-hexadecane; methyl ester hexadecanoic acid; benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, methyl ester; L-(+)-ascorbic acid 2,6-dihexadecanoate; and octadecanoic acid. This study provides scientific validation for the use of the Sunda porcupine's quills in traditional medicine and highlights the potential for further research in animal bioprospecting.

Frequent encounters with the greater bandicoot rats (Bandicota indica) following high rodent damage towards rice crops and lack of information on the species had encouraged this study to be conducted to test the relevance of using first- and second-generation rodenticide in a field efficacy test. This study also attempts to detect any sign of resistance of current rodent pest populations towards chlorophacinone (0.005%) and flucoumafen (0.05%) for the control of field rats predominant rice field agrosystem of the Kedah in northern peninsular Malaysia. Six different treatments over dry and wet rice planting season together with trapping exercise. The observation was evaluated based on the number of active burrows, counting tiller damage due to rodent attack and trapping index. The results indicated that flucoumafen gives better rodent control and has a better impact (p < 0.05) although chlorophacinone is still relevant to be applied (p < 0.05). Treatments during the off-planting season (September-February) are more effective compared to the main planting season (March-August). Rodent control during the early off-planting season is encouraged for better rodent management in the rice field and the use of bait stations to increase the weatherability of the baits.

Limnonectes leporinus, the endemic giant river frog, is a riparian (stream dwelling) species that lives along streams with moderate to steep gradients. The most serious threats to the species are deforestation caused by severe clear cutting, which fragments its distribution, and overhunting for local consumption. Excessive landscape modification alters habitat, making it critical for an organism to maintain heterozygozity for the population to be fit to adapt to a changing environment. The goal of this research was to project suitable habitats and predict the potential for habitat connectivity to allow gene flow across the Sarawak landscape. The presence data file and environmental layers were converted into ASCII format using ArcGIS and then used in MaxEnt modelling to generate the map of suitable habitats. To perform the connectivity model, the potential habitat model and genetic attributes of haplotype data were computerised in Circuitscape software. The findings revealed that suitable habitats corresponded to species distribution in lowland areas with sustainable stream networks as breeding sites, while higher elevations were identified as unsuitable habitats. Gene flow data, on the other hand, revealed that connectivity circuits are mostly found in unprotected forest, which includes development areas and private lands. As a result, prioritising conservation areas should include local governments and landowners in proper landscape management as well as species management strategies. This indirectly sustains and protects Borneo's forests, flora and fauna.

Plants are rich in tandem repeats-containing proteins. It is postulated that the occurrence of tandem repeat gene families facilitates the adaptation and survival of plants in adverse environmental conditions. This study intended to identify the tandem repeats in the transcriptome of a high potential tropical horticultural plant, roselle (Hibiscus sabdariffa L.). A total of 92,974 annotated de novo assembled transcripts were analysed using in silico approach, and 6,541 transcripts that encoded proteins containing tandem repeats with length of 20-60 amino acid residues were identified. Domain analysis revealed a total of nine tandem repeat protein families in the transcriptome of roselle, which are the Ankyrin repeats (ANK), Armadillo repeats (ARM), elongation factor-hand domain repeats (EF-hand), Huntingtin, elongation factor 3, protein phosphatase 2A, yeast kinase TOR1 repeats (HEAT), Kelch repeats (Kelch), leucine rich repeats (LRR), pentatricopeptide repeats (PPR), tetratricopeptide repeats (TPR) and WD40 repeats (WD40). Functional annotation analysis further matched 6,236 transcripts to 1,045 known proteins that contained tandem repeats including proteins implicated in plant development, protein-protein interaction, immunity and abiotic stress responses. The findings provide new insights into the occurrence of tandem repeats in the transcriptome and lay the foundation to elucidate the functional associations between tandem peptide repeats (TRs) and proteins in roselle and facilitate the identification of novel biotic and abiotic response related tandem repeats genes that may be useful in breeding improved varieties.

Paphiopedilum primulinum and Paphiopedilum glaucophyllum have unique labellum colour and shaped like lady's slippers. These orchids are from the Cochlopetalum section, which is exclusively found in Sumatra and Java. There are so many people that desire to collect these plants illegally. Due to extensive commercial exploitation, Paphiopedilum is in danger of going extinct. Tissue culture techniques are utilised to conserve threatened orchid germplasm in a short time. The success of the in vitro culture depends on the accuracy of the basic media composition used. The Ambon Lumut banana (ALB) can accelerate plant growth and cell division. Banana added to the culture medium was prepared by mashing the ripe flesh (3.5 months old) using a mortar. This research aims to investigate the effect of banana homogenate supplemented media for the orchids P. primulinum and P. glaucophyllum based on the parameters of difference of plant height (calculated from the base of the stem to the tip of the plant stem), number of leaves, and number of roots. The measurement method was carried out using a ruler with a centimetre scale. Observations and documentation were carried out once a week for 7 weeks after planting (WAP) for P. primulinum and P. glaucophyllum. The results showed that ½ Murashige and Skoog (MS) + ALB homogenate is a better medium for P. primulinum and P. glaucophyllum growth than media without banana homogenate. The highest values of plant height, leaf growth and root growth of P. primulinum with banana homogenate were 0.44 cm, 0.63 leaves, and 0.50 roots, respectively. The highest values of plant height and leaf growth of P. glaucophyllum were 0.75 cm and 1.90 leaves, respectively. Culture medium added banana homogenate was able to support the propagation of plants, some of which are returned to nature and others used for industrial purposes (conventionally cultivated by the community).

The floral biology of Calamus is relatively unknown except for several species. In this study, Calamus lobbianus and Calamus pygmaeus were selected to represent the non-climbing rattan of the Sundaland's flagellate group. Observations on phenology, floral rewards and floral visitors as well as experiments on the breeding mechanism and operational sex ratio were performed for both species. For both species, anthesis started in the early morning for pistillate and staminate plants, ended by late noon (staminate plants) but lasted till the next day in pistillate plants for both species. Although both species appeared to be aseasonal in flowering, C. lobbianus exhibited a male-biased population while C. pygmaeus did not exhibit any sex bias. Nectar was observed to be extruded from the base of the petals of C. lobbianus of the staminate flowers and sterile staminate flowers of the pistillate plants. The concentration and volume of the nectar of the staminate flower and sterile staminate flower of C. lobbianus peaked at c. 11% and 9 μL around 1100 (Day 1) and c. 13% and 8 μL around 0930 (Day 1), respectively, but only appeared as a layer of glistening exudate in C. pygmaeus. Floral scent was not detected in any of the inflorescences of both species. Several insect visitors were observed to be the primary visitors of both Calamus species which include two species of Tetragonula, a species of Liostenogaster sp., and Stenodyneriellus sp. Experiments on breeding mechanism of C. lobbianus and C. pygmaeus indicate that both species are most likely apomictic. C. pygmaeus is capable of vegetative propagation through the rooting at the tip of inflorescence.

Seed vigour is a desirable trait especially for direct seeded rice (DSR) cultivation. Seeds with high vigour could improve seed germination, support seedlings in competing with weeds for water and nutrients, and improving seedling establishment throughout the early stages of crop growth. The success of DSR system which account for more 25% of world cultivation areas is highly dependent on the seed vigour and seedling establishment. Seed priming is a promising technique to improve seed vigour. Proline is an amino acid that has been well studied for its roles in plants under different environmental stress conditions. Nevertheless, the effect of proline as a seed priming agent in improving seed vigour in rice remain elusive. In this research, the effect of 24 h of proline priming at various concentrations (0 mM, 1 mM, 2 mM, 10 mM and 20 mM) on rice seed vigour, amylase activity, and total soluble sugar (TSS) content of a Malaysia indica rice variety, MR269 was investigated. Results showed that seeds primed with lower concentration of proline (0 mM, 1 mM and 2 mM) had better germination responses while priming at high concentrations (10 mM and 20 mM) reduced seed germination. Among the concentration tested, priming with 1 mM proline enhanced seed vigour with significantly higher germination percentage (GP), germination rate index (GRI) and seedling vigour index (SVI). In addition, proline primed seeds also exhibited increased amylase activity and TSS content as compared to unprimed seeds. However, priming seed with 20 mM proline was detrimental to the seed vigour and seedling growth whereby lower GP, GRI and SVI and higher mean germination time (MGT) were observed. In short, this study shows that proline could be a potential seed priming agent to improve seed vigour in rice.

The pigtailed monkey (Macaca nemestrina) is one of the species that have potency like the cynomolgus monkey that is widely used as an animal model for asthma study. The CCL7 gene has potential as a genetic marker because of the secreted chemokine that plays a role in asthma. The aims of this research are to characterise the CCL7 gene of pigtailed monkey, compare the structure of their CCL7 gene with other primate species and determine model 3D structure protein prediction of CCL7 protein. The amplicons were sequenced, and the results were analysed by the bioinformatics technique. The 3D CCL7 protein structure was predicted using I-TASSER. We have isolated 2221 bp sequences CCL7 gene and 109 amino acids from pigtailed monkey. Variation of CCL7 gene sequence between pigtailed monkey and other primate species (Macaca fascicularis, M. mulatta and Homo sapiens) was found in exon 1, exon 2 and exon 3 as CDS (Coding DNA Sequence) region. The analysis homology of nucleotides and amino acid sequences of the CCL7 gene indicated that the pigtailed monkey and three other primate species have a high homology rate with an identity score above 90%. Meanwhile, a comparative analysis of CDS and amino acid regions showed that the pigtailed monkey also has the highest similarity with the three other primate species with more than 90% identity score. The 3D structure protein prediction model of the CCL7 pigtailed monkey revealed the highest similarity with H. sapiens with an identity value of about 95%. Therefore, the pigtailed monkey CCL7 gene has high similarity with H. sapiens, which means that based on molecular similarity, the pigtailed monkey has the potential to be an animal model for asthma study, especially the study of molecular and the role of CCL7 in asthma pathogenesis.

Ipomoea staphylina Rome & Schult, entrenched in ethnomedicinal practices, is recognised for its efficacy in treating stomach disorders. Traditionally used in Dharmapuri, Tamil Nadu for stomach ulcers, its matured stem bark latex is therapeutically relevant, especially for Helicobacter pylori (H. pylori) infections. This prompts scientific exploration into its antibacterial properties. The research validates the antibacterial efficacy of I. staphylina extracts against H. pylori, scrutinising the whole plant and matured stem through a comparative pharmacognostic analysis. Utilising herbal standardisation techniques, we confirm the heightened purity of the powder. Antimicrobial assessments show exceptional efficacy of DME (dried Ethanolic extract of I. staphylina) and HLS (hydro alcoholic extract of I. staphylina) extracts. Quercetin isolation by using advanced instrumentation (Nuclear magnetic resonance [NMR], High resolution mass spectrometry [HR-MS], High-performance thin-layer chromatography [HPTLC], Fourier transform infrared spectroscopy [FTIR]) ensures precise compound identification. This methodology guarantees an exhaustive analysis, confirming purity and identifying bioactive components. Standardisation underscores the elevated purity of I. staphylina, with phytochemical screening revealing a predominant presence of phenolics and flavonoids. Antibacterial investigations highlight significant activity, particularly with DME and HLS extracts. These findings substantiate I. staphylina's medicinal significance, especially its matured stem latex, as a promising treatment for H. pylori-induced stomach ulcers, affirming traditional use by Dharmapuri villagers.