 Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
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- Effect of Pre-treatment on The Impregnation of Osmotically Dehydrated
Fruits: A Review
Authors: SALIZA ASMAN, SHALINI RAJA
Pages: 1 - 21
Abstract: Osmotic dehydration is one of the alternative methods that is most frequently employed in the food industry to prevent large accumulation of food waste and postharvest losses, although it has a devastating influence on the textural and structural properties of the fruits. Considering that, this review offers innovative ideas and views on the impact of calcium salts, specifically calcium chloride and calcium lactate, on the impregnation of osmotically dehydrated fruits, along with various pre-treatments. Calcium chloride and calcium lactate salts assist in conserving the quality of fruits in the sense of colour, sensory, textural, structural, and other characteristics since some fruits are very perishable and rapidly degrade. Additional data showed that pre-treatments like blanching, freezing, drying, and ultrasound negatively affect calcium salt impregnation on fruit samples. The focus of this review is mainly on the preservation method of impregnating osmotically dehydrated fruits with calcium chloride and calcium lactate salt treatments, as well as blanching, freezing, drying, and ultrasound pre-treatments.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5010.2023
Issue No: Vol. 13, No. 1 (2023)
- A Brief Review of the Nutritive Value and Chemical Components of Bat Guano
and Its Potential Use as a Natural Fertiliser in Agriculture
Authors: SITI-SYAMIM NURFATIHAH ABD RAHMAN, ROBERTA CHAYA TAWIE TINGGA, MOHAMAD FHAIZAL MOHAMAD BUKHORI, SHARIFAH MONA ABD AZIZ ABDULLAH
Pages: 22 - 31
Abstract: New and improved fertilisers are constantly being introduced to the market to help increase crop yields. However, the common usage of chemical fertilisers had brought upon negative impacts to the environment and the study for sustainable fertiliser is still ongoing. This review will highlight the usage of bat guano as a valuable fertiliser which has a potential to diminish the effects of chemical fertiliser usage, increase yield and is cost effective. Its role as a fertiliser can support the agricultural growth and in turn provides additional care for plants. The chemical compositions of guano which was found to be subpar with other fertilisers support its usage of guano as an alternative for crop yield enhancement. Plant growth performance that shows a significant positive impact of guano on crops, further demonstrates its usage as organic fertilisers. In-depth study of the chemical composition of guano should be pursued as the fertiliser has high beneficial value to the ecology and economy.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5100.2023
Issue No: Vol. 13, No. 1 (2023)
- Evaluation of Generic Fertiliser as an Alternative Inorganic Nitrogen
Source for Ethanolic Glucose Fermentation by Saccharomyces cerevisiae
Authors: THRACESY MUNAH ASSAN, EFFA SHAHRINA SAHARI, NURASHIKIN SUHAILI, DAYANG SALWANI AWANG ADENI, DEVAGI KANAKARAJU , MICKY VINCENT
Pages: 32 - 41
Abstract: In the studies and production of bioethanol, the preferred fermenting yeast (Saccharomyces cerevisiae) is usually cultured in liquid broth that contains yeast extract and peptone. However, the use of these laboratory and scientific grade chemicals is costly, making them impractical for mass bioethanol production. Therefore, this study was conducted to evaluate the feasibility of glucose ethanolic fermentation by S. cerevisiae using generic fertiliser formulations to provide inorganic nitrogen, phosphorus, potassium and trace elements (NPK-TE). Fermentation media of different generic fertiliser strength at 0.5X, 1.0X and 2.0X Fertiliser Nitrogen Equivalents (FNE), as compared to the conventional Yeast Extract-Peptone (YEP) medium as control, was used as fermentation broth during the ethanolic fermentation of glucose. Based on the results, S. cerevisiae cultured in YEP broth produced the highest cell concentration for both wet (21.93 g/L) and dry cells (3.87 g/L), with rapid increment observed in the first 72 h of fermentation. By the end of the fermentation period, lactic acid (3.14 g/L) and acetic acid (0.96 g/L) levels were recorded to be the lowest in YEP medium while their concentration (lactic acid, 8.08 g/L) and (acetic acid, 2.67 g/L) were highest in 2.0X FNE fertiliser medium. Results indicated that the best theoretical ethanol yield (TEY) among the fertiliser media was achieved when fermentation was performed in the 0.5X FNE fertiliser medium, with a TEY of 86.18%. TEY yields were 78.68% and 51.54% in broth with 1.0X and 2.0X FNE, respectively. In general, all three fertiliser media supported ethanolic fermentation of glucose, with the 0.5X FNE fertiliser broth showing a yield that is significantly close to the conventional YEP medium, as seen in the statistical analysis. Similarities in other fermentation profiles such as acetic acid, lactic acid, and biomass production, as well as glucose utilisation, between the results from the YEP samples and samples from the fertiliser broths (at 0.5X and 1.0X FNE) have also shown that generic fertiliser has the potential to be used as an alternative medium to replace the conventional YEP to produce ethanol at a lower cost.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.4978.2023
Issue No: Vol. 13, No. 1 (2023)
- Identification of Carbohydrates Metabolic Related Enzymes for Lipid
Production in Botryococcus sp., a Microalgae Isolated from Taman Negara
Endau Rompin
Authors: ZUBAINATU ABBA, SITI FATIMAH ZAHARAH MOHAMAD FUZI, HAZEL MONICA MATIAS-PERALTA
Pages: 41 - 53
Abstract: Botryococcus is a microalgal genus known for its ability to generate and accumulate substantial amounts of lipids via carbohydrate metabolism. This work determined the metabolic pathways and enzymes involved in carbohydrate metabolism leading to increased synthesis of fat in Botryococcus sp. Relevant intracellular and extracellular metabolites were extracted and quantified using chromatographic analysis. Enzymes involved in carbohydrate metabolism leading to lipid formation in Botryococcus sp. under natural conditions were also discovered by one-dimensional gel electrophoresis followed by proteomic mass spectrometry (LC-MS/MS) and database searching. Proximate analysis demonstrated 23.0% total carbohydrate, 16.0% protein and 61.0% lipid per milligram biomass dry weight of Botryococcus sp. The extracellular metabolites constitute mostly of cyclohydrocarbons, nitrogenated hydrocarbons, siloxanes, phenols, and phenol derivatives. A glycolytic enzyme “enolase,” which can create phosphoenolpyruvate and subsequently convert it into pyruvate, was found in this study. This study revealed that enolase provided an alternate pathway to export fixed carbon to the cytoplasm, hence providing a shorter route to lipid production than the normal process via the plastid leading to the manufacture of more lipids in the cells of Botryococcus sp. than other microalgae of the same group.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5080.2023
Issue No: Vol. 13, No. 1 (2023)
- Contamination of Bacillus cereus in Foods Sold at Ramadan Bazaar in
Kuching, Sarawak
Authors: NURUL AZYLA AZMI, SHARIFAH AMINAH SYED MOHAMAD, ABU MUSLIM AHMAD, NAJIHAH MOHD SANI, SITI ROHA AB MUTALIB, FAZDLINA SAPEE
Pages: 54 - 61
Abstract: Every year there are reports of food poisoning involving food sold at the Ramadan bazaar and one of the causes of food poisoning is Bacillus cereus. This study aimed to determine the contamination level of B. cereus and the antimicrobial susceptibility profile of the isolates in food sold at Ramadan bazaar in Kuching, Sarawak. A total of 155 samples from five food categories were collected from six Ramadan bazaars in three locations around Kuching. Overall, 32 (21%) food samples were found positive for B. cereus. Cooked rice showed the least satisfactory levels of B. cereus among the food categories and nasi lemak was the type of food that highly contaminated with B. cereus. Antibiotic susceptibility assessment showed that B. cereus isolates were highly resistant to ampicillin, amoxicillin/clavulanic, penicillin and cefotaxime in this study. The findings of this study showed that B. cereus has the potential to cause food poisoning to Ramadan bazaar consumers due to the high mean count in some types of food. Therefore, this study can be used as basic data for B. cereus control measures in food sold at the Ramadan bazaar.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5104.2023
Issue No: Vol. 13, No. 1 (2023)
- Fish Communities of Tropical Headwater Streams Under Multiple Land-use
Influence
Authors: STEFFIE PHILIP, GABRIEL TONGA NOWEG, ANDREW ALEK TUEN, JONGKAR GRINANG
Pages: 62 - 71
Abstract: The intensive development of agricultural activities can be a major threat to the extinction of fish fauna in the tropical headwater streams of Borneo Island. Insufficient information on the influence of multiple land-use on fish communities can lead to failure in preserving ecological buffer zones along stream channels and the loss of aquatic biodiversity. We investigated fish communities of tropical headwater streams in Bau District of Sarawak State that flow through different types of land-uses. It is hypothesised that multiple land-use influent fish diversity and abundance. Fish were sampled at three headwater streams, Sg Bu’un, Sg Dian and Sg Sibomou of Sarawak Kanan River that have multiple land use in the catchment areas. The assessment of land use activities and fish sampling were done once in dry and rainy months. The assessment of land use showed that the distribution of agricultural activities is not consistent across the water catchments of the three headwater streams, which among others could be depending on soil fertility and the interests of the farmers. Oil palm plantation was the major agricultural activity in the catchment of headwater streams. The aboveground biomass varied with the type of land use, size of coverage, and age of the forest or plantation. The fish fauna of the three headwater streams was represented by 25 species in ten families and six orders, which was dominated by the family Cyprinidae. The cyprinids made up 17% of the total individuals with three dominant species are Barbodes sealei, Rasbora cryptica and Oxygaster anomalura. The diversity index of Shannon was significantly different among the three headwater streams. The headwater streams with high coverage of oil palm plantations showed significantly low species richness and high number of individuals. Fish richness and abundance in dry season were significantly lower than rainy season. The less sensitive species such as Systomus rubripinnis, Barbodes sealei, Rasbora cryptica,and Parachela oxygastroides were dominant in three headwater streams in both wet and dry months. The findings of this study may suggest that the width of buffer zone along stream channel could be estimated by integrating size of the major land use in the catchment, precipitation, and management practices of each type of land-use.
PubDate: 2023-06-27
DOI: 10.33736/bjrst.5321.2023
Issue No: Vol. 13, No. 1 (2023)
- Anthocyanin Content and Antioxidant Activity of Red Chrysanthemum
(Chrysanthemum morifolium Ramat.) at Different Flower Ages
Authors: ANISA MAGFIROH, ENDAH DWI HASTUTI, YULITA NURCHAYATI, NINTYA SETIARI
Pages: 72 - 80
Abstract: Chrysanthemum sp. is a floricultural plant of the Asteraceae family with high economic value. The anthocyanin pigment in red chrysanthemum acts as an antioxidant, the content of which can be influenced by genetic factors such as the physiological age of the flower. This study aimed to determine the effect of flower age on anthocyanin content and antioxidant activity in red chrysanthemum plants. The age of red chrysanthemum used was 115 Days After Planting (DAP) (early bloom stage), 120 DAP (half-bloom stage), 125 DAP (blooming stage), and 134 DAP (wilted flower). The anthocyanin content was analysed using spectrophotometric methods. Antioxidant activity was determined by the DPPH method and then the absorbance was measured using a UV-Vis spectrophotometer. The results showed that the highest anthocyanin content was obtained at the age of 134 DAP at 3.56 mg/g, followed by the age of 115 DAP at 2.40 mg/g, then at 125 DAP at 1.95 mg/g and the lowest at 120 DAP at 1, 69 mg/g. The highest antioxidant activity was shown in chrysanthemum flowers aged 115 DAP which had an IC50 value of 288.85 g/ml. The research shows that wilted chrysanthemum flowers still contain anthocyanins so it can be used in various industrial fields such as chrysanthemum tea and additives for soap.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5336.2023
Issue No: Vol. 13, No. 1 (2023)
- Morphological and Physiological Development of Pyricularia oryzae Isolates
from North-western Region of Sarawak on Different Media under Laboratory
Conditions
Authors: ELISSA STELLA RAFAEL, YEO FREDDY KUOK SAN, NOR AIN HUSSIN, VU THANH TU ANH, ANG POH SIM, EWE ZHANG HUA, LAI LEE SAN
Pages: 81 - 92
Abstract: Rice blast (causal agent: Pyricularia oryzae) is an important disease of rice in Sarawak. Understanding the pathogen’s morphological characteristics, genetic diversity and pathogenicity is important. Having a suitable medium for culturing and maintaining P. oryzae is important to ensure the availability of inoculum or materials under laboratory conditions. Oatmeal agar (OMA) and potato dextrose agar (PDA) are common media used for growing P. oryzae. OMA allows better mycelial growth and better sporulation as compared to PDA. There are also other alternatives such as fresh rice leaf agar and rice straw agar. Although OMA seems to be the best medium, unfortunately the opaqueness of the medium causes difficulty in observing the morphology and growth of mycelia. In addition, it is known that different isolates of P. oryzae will respond differently to different media. This study aims to identify the best media for culturing and maintaining P. oryzae isolates from Sarawak. A total of 14 P. oryzae isolates were characterised for their morphological characteristics, growth rate and sporulation rate using seven growing media. These 14 isolates included seven newly identified isolates in this study and seven isolates from a previous study, which were verified using internal transcribed spacer DNA sequence. The colony surface of the 14 P. oryzae isolates varied on different growing media. The pigmentation of colony surface varied from different shades of grey, translucent light brown, white and colourless. Pyricularia oryzae isolates grew better on OMA and PDA, while OMA was the best for sporulation. These two media can be recommended for culturing and maintaining different P. oryzae isolates under laboratory conditions.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5258.2023
Issue No: Vol. 13, No. 1 (2023)
- The Prevalence of Vibrio cholerae and Vibrio parahaemolyticus Virulence
Genes and Multiple Antibiotics Resistant (MAR) Assessment from Local
Shrimp Farm in Sarawak
Authors: DAYANG NAJWA AWG BAKI, ELEXSON NILLIAN, DALENE LESEN
Pages: 93 - 107
Abstract: Excessive and improper antibiotic use in animals raised for human consumption can increase the risk of antibiotic-resistant infections, causing more harm and higher treatment costs. This study examined the virulence genes and antibiotic susceptibility of Vibrio cholerae and V. parahaemolyticus, two bacteria that can affect public health. A total of 32 water samples were collected from August to December 2021 from a shrimp farm in Sarawak. Ten (n = 10) V. cholerae and ten (n = 10) V. parahaemolyticus presumptive isolates were identified and purified using selective agar and duplex-PCR method. The results showed that 70% of V. cholerae isolates contained rtxA and 90% of V. cholerae isolates contained rtxC while tdh and trh were not found in V. parahaemolyticus isolates. Antibiotic susceptibility testing showed that all V. cholerae and V. parahaemolyticus isolates were resistant to at least one antibiotic with the mean Multiple Antibiotic Resistance (MAR) indices of 0.34 for V. cholerae and 0.24 for V. parahaemolyticus. The MAR index of 0.20 and greater indicates that antibiotics are heavily contaminating the shrimp farm water. This study highlights the need for the proper administration of antibiotics in shrimp farming environments to reduce the risk of antibiotic-resistant infections caused by V. cholerae and V. parahaemolyticus. Water treatment should also be implemented before being released back to the environment to lessen the negative impact brought by the rearing of shrimp from a highly contaminated source.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5375.2023
Issue No: Vol. 13, No. 1 (2023)
- Morphometric Studies of Accessions of Duranta erecta L. (Vebernaceae)
Complex in Nigeria
Authors: ABDULQUADRI SAGAYA, ABDULLAHI ALANAMU ABDULRAHAMAN
Pages: 108 - 119
Abstract: Studies were conducted to broaden the systematic knowledge of the genus Duranta erecta L., to contribute a better understanding of their taxonomic and evolutionary relationships. Previous studies have pointed out complexity in the taxonomy and nomenclature of the species. A total of 224 samples were collected from six geo-political zones of Nigeria, and were grouped into 38 accessions. The plants were compared using 21 morphological characters involving qualitative and quantitative characteristics. Multivariate analyses such as Principal Component Analysis (PCA) and Cluster Analysis (CA) were employed to evaluate the intraspecific variabilities. The results showed that all the plants exhibited significant differences in all the quantitative attributes with the variegated type having the longest and widest leaves ranging from 12.20 cm and 5.08 cm, respectively. The qualitative characters delimited the plants accessions into distinctive groups of eight morphological forms namely; green bush, yellow bush, variegated yellow, variegated white, variegated yellow double, plain yellow, broad green, thorny green type. The PCA showed that leaf length, leaf width, internode length and length of inflorescence were some of the quantitative characters while leaf shape, leaf colour, leaf margin, flower colour and leaf apex are some of the qualitative traits that accounted for the delimitation. Unpaired Weighted Group Multivariate Analysis (UPGMA) using the Euclidian separated the 38 accessions into two major clusters; cluster I (flower producing) and cluster II (non-flower producing) Duranta erecta. Morphological variations and field observations suggested that there could be gene flow among the accessions of Duranta erecta studied and gene flow is an important factor in population genetics, shaping the diversity of species.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5277.2023
Issue No: Vol. 13, No. 1 (2023)
- Body Indices and Population Dynamics of Setipinna breviceps (Cantor, 1849)
from Batang Lassa Estuary, Sarawak, Malaysia
Authors: M. GOLAM MUSTAFA, AMY HALIMAH RAJAEE, HADI HAMLI, KHAIRUL ADHA A. RAHIM
Pages: 120 - 131
Abstract: The Setipinna breviceps is a commercially important and highly esteemed food fish. This species has scant of scientific formation particularly on population parameters like growth, mortality and recruitment. The present study aimed to estimate the body indices and population parameters of Setipinna breviceps of Batang Lassa Estuary (BLE). Samples were collected between April 2019 and September 2020. A local made bag net known as Gnian (mesh size 1.25 to 4.00 cm) was used for sampling the fish. A total of 287 qualified specimens were used for this study. The length and weight of individual fish was measured to the nearest 0.1 cm and 0.01 g, respectively. The length ranged from 5.50 to 24.00 cm and growth coefficient (b) was 2.563 (R2 = 0.87) which clearly indicated a negative allometric growth. About 50% of individuals showed flat or slender body (Kn<1) and 47% of the specimens were rounded shaped (Kn>1) while 2.44% of fishes measured an ideal shape (Kn = 1). The parameters of growth L∞, K and ϕ’ were estimated at 24.15 cm, 0.23 yr-2 and 2.13, respectively. The estimated natural mortality and fishing mortality were 0.74 and 0.29 yr-2, respectively and exploitation rate was 0.28. The recruitment pattern during the study was observed at two possible unequal peaks. The present study concluded that the anchovy was under exploited (E<0.5) as demonstrated by the under-sized fishes caught with small mesh size net. However, considering the minimum lengths and length at first catch, the BLE could be a productive nursery ground for S. breviceps. Therefore, management actions are required to avoid juvenile catches.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.4943.2023
Issue No: Vol. 13, No. 1 (2023)
- Bacillus Composted Paddy Husk as a Plant Nutrient Source to Promote
Vegetative Growth and Nutrient Uptake in Maize
Authors: CARLINA FREDDIE SIMOL, JOHN KEEN CHUBO, KHALID NAWI, IRA CARLBRENIE SIMOL
Pages: 132 - 141
Abstract: Paddy husk (PH) is a waste generated from rice production that can be composted into organic fertiliser. Ligninolytic active Bacillus spp. from termite gut were added during the composting process to enhance the agronomic properties of compost produced from PH. This pot study was conducted using maize (Thai Super Sweet hybrid F1) as a test crop to determine the effects of using Bacillus composted PH in supplementing essential nutrients when used in tropical agricultural soil. A total of 144 planting pots, consisting of 12 treatments, were arranged in a Randomized Complete Block Design (RCBD) with three blocks, three replications and four sub-samples per replication. Maize growth namely plant height and leave number were recorded from 14 until 48 days after planting. Maize plants were harvested at 48 days after planting (tasseling stage) and total plant dry weights were recorded. Each plant part was ground and analysed for total N, P, K, Mg and Ca. Soil samples from the pots were sampled and analysed for TOC, pH, EC, total N, total P, available P, K, Mg and Ca. The results at 48 days after planting showed that Bacillus composted PH contributed to an increased by 24.29 to 31.67% in plant height, 53.84 to 61.61% in total plant dry weight and 9.09 to 16.67% in leaf number when compared to plants supplied with standard fertiliser. The use of Bacillus composted PH also improved soil pH, increased soil total N, total P, exchangeable K, Ca, and Mg. Maize treated with Bacillus composted PH showed higher nutrient uptake by 42.79 to 67.89% N, 30.05 to 56.25% P, 61.39 to 70.34% K, 47.39 to 69.94% Ca, and 76.62 to 83.74% Mg when compared to maize treated with standard fertiliser. This study suggests that Bacillus composted PH can promote vegetative growth in maize by acting as soil amendment and providing sufficient nutrients to the plant. Therefore, Bacillus composted PH has great potentials in promoting a more environmentally friendly and sustainable cropping practices which can benefit the environment and society.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5271.2023
Issue No: Vol. 13, No. 1 (2023)
- Physical Quality of Eggs in Pengging Duck (Anas platyrinchos) after
Administration of Nanochitosan as a Feed Additive
Authors: SUNARNO, NURUL ANNISA, SRI ISDADIYANTO
Pages: 142 - 152
Abstract: The problem often encountered by laying duck breeders is a decrease in the physical quality of eggs. Nanochitosan is a polysaccharide that has the potential as a feed additive to improve the physical quality of eggs in pengging ducks. The use of nanochitosan at levels of 2.5, 5.0, 7.5 and 10.0 g/kg of feed can improve digestive performance and nutrient absorption in ducks. The purpose of this study was to determine the effect of nanochitosan as a feed additive on the physical quality of eggs in pengging ducks. This study used a completely randomised design with five groups and five ducks per group. The treatments consist of control and the addition of nanochitosan as a feed additive with a concentration of 2.5, 5.0, 7.5 and 10.0 g/kg of feed. The variables observed in this study included the haugh unit (HU), yolk index (IKT), yolk weight, white weight, egg weight, shell thickness, and egg shape index. The research data were analysed using ANOVA with a significance level of 5%. The results showed that the addition of nanochitosan at different levels (2.5, 5.0, 7.5 and 10.0 g/kg of feed) had a significant effect on the measured egg quality consisting of HU, IKT, egg yolk weight, egg white weight, egg weight egg, shell thickness, and egg shape index. The study concluded that nanochitosan can be used as a feed additive to improve the physical quality of eggs in pengging ducks. The use of nanochitosan with different levels as a feed additive can be useful for others by providing a reference about the levels of nanochitosan used as a feed additive which can improve the physical quality of duck eggs and become important information in increasing exploration in the use of nanochitosan products. This study is expected to open opportunities for further research in the future about the mechanistic effects of nanochitosan in improving egg quality and productivity of laying ducks.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5244.2023
Issue No: Vol. 13, No. 1 (2023)
- Diversity and Distribution of Predatory Insects in Non-outbreak and
Post-outbreak Estates of an Oil Palm Plantation in Beluran District,
Sabah, Malaysia
Authors: MOHAMAD HARRIS NASIR, MUHAMMAD HAFIZ AIMAN, MOHANARAJ SITHAMPALANADANARAJAH, JOSHUA MATHEWS
Pages: 153 - 164
Abstract: Hemipteran predator species from the families Reduviidae and Pentatomidae are a group of insects that play a crucial role as natural enemies of leaf-eating pests in oil palm plantations by maintaining the population of pests below the economic. The promotion of natural enemies can be an effective and sustainable approach to pest management. A census was conducted between June and August 2022 in nine plantations in Beluran district, Sabah to compare the species composition between recent leaf-eating pest in outbreaks and non-outbreak estates using sweep nets and active visual surveys. A total of 355 individuals from seven species of two different families were recorded, with Reduviidae being the most abundant family: Sycanus annulicornis, S. affinis, Cosmolestes picticeps, Velinus nigrigenu, Campsolomus nr. sp. (Hemiptera: Reduviidae), Platynopus melanoleucus and Eocanthecona furcellata (Hemiptera: Pentatomidae). The diversity indices of the predatory insects were significantly higher (p<0.01) in non-outbreak estates (H’ = 1.682, 1-D = 0.763) compared to post-outbreak estates (H’ = 1.344, 1-D = 0.683), which recorded a higher dominance value (D = 0.32) of a single species, leading to a decrease in the diversity indices. The Pentatomidae family was only found at non-outbreak estates, while the other Reduviidae species were highly abundant and distributed throughout all study locations. The S. annulicornis and S. affinis were only found on beneficial plants, while E. furcellata and P. melanoleucus were highly abundant within the oil palm planting area. These findings provide insights into the importance of maintaining the beneficial plant and reducing the impact of pest outbreaks on the diversity and abundance of predatory insects in oil palm plantations.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5315.2023
Issue No: Vol. 13, No. 1 (2023)
- Morphometric Analysis of Sexual Dimorphism in Penthicodes farinosus
(Weber, 1801) (Hemiptera: Fulgoridae) from Sarawak
Authors: AHMAD IRFAN ABDUL RAZAK, SITI NURLYDIA SAZALI, RATNAWATI HAZALI, FARAH NABILLAH ABU HASAN AIDIL FITRI , ISAAC STIA MARCELLINUS
Pages: 165 - 172
Abstract: The Penthicodes farinosus are strikingly coloured insects and can be found in India, Myanmar, Peninsular Malaysia, Java, Sumatra, Sulawesi, the Philippines, and Borneo. Despite their wide distributional range in Asia with a common occurrence in Borneo, morphometric investigation of P. farinosus is still lacking. The study is aimed to investigate the morphological variations of this species between two different sexes in Sarawak, Malaysian Borneo. Eleven morphometric characters were measured from 183 specimens (69 males and 114 females). The data were analysed using an independent t-test, Principal Component Analysis (PCA) and Discriminant Function Analysis (DFA). Sexual dimorphism index (SDI) was found ranging from 0.044 (LV) to 0.1008 (BTg) indicating females were larger than males. In PCA, cumulative variations of 59.9% were recorded from two principal components, showing higher loadings in the length of tegmen (LTg) and total length (TL). DFA revealed a single function that explains a canonical correlation of 0.895 with 100% variation. The Wilks’ Lambda values of 0.199 were highly supported with p<0.0001. The highest loadings for the model are LTg and TL. The two variables were further tested using Leave-One-Out Cross Validation (LOOVC) method which resulted in 97.2% cases being correctly classified as male or female. This suggests LTg and TL can be useful in separating both sexes of P. farinosus.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5283.2023
Issue No: Vol. 13, No. 1 (2023)
- Species Diversity and Assemblage of Mangroves at Setiu Wetland,
Terengganu, Malaysia
Authors: ABUL FAIZ MOHAMMAD ARIFUR RAHMAN, MOHAMMAD AHSANUL ISLAM, MOHD HANAFI IDRIS, MD KHURSHID ALAM BHUIYAN, MOHAMMAD MAMUN CHOWDHURY, MUYASSAR H. ABUALREESH, ABU HENA MUSTAFA KAMAL
Pages: 173 - 190
Abstract: Mangroves in wetland ecosystems are diverse and play significant role in the adjacent communities on which they are dependent for their livelihoods. It is also important for fishery resources and nutrient inputs in marine and brackish water ecosystems. However, little is known about the tropical wetland lagoon ecosystems, particularly mangrove diversity and assemblages. Therefore, this present study was initiated to observe the mangrove species diversity and assemblages together with the conservation status in an important tropical wetland ecosystem in Setiu, Terengganu, Malaysia. In a variety of landward and small fringe island areas, three zones of square plots were selected (zones 1, 2 and 3) to address the objectives of this study. As a result, a total of 20 true mangrove species belonging to 11 genera from nine families were documented, of which, Avicennia rumphiana was listed as vulnerable (VU) by the IUCN. Twelve species of mangrove associates from 11 genera and nine families were also found in the investigated zones at Setiu. One of the mangrove associates, Intsia bijuga, was designated as vulnerable (VU) by the IUCN. The Shannon diversity index (H') of mangroves was found to be 1.08 at Setiu Wetland. Rhizophora mucronata was found to be well-expanded (H' = 1.05) followed by A. rumphiana, A. officinalis, Heritiera littoralis, A. corniculatum. Excoecaria agallocha, Lumnitzera racemosa, and A. ebracteatus (H' = 0.0) as the lowest. The findings of the present study revealed that mangroves in the Setiu Wetland are diverse and healthy compared to other mangrove ecosystems in the region. To maintain the health and function of the mangrove ecosystem in Setiu Wetland, proper monitoring is required.
PubDate: 2023-06-30
DOI: 10.33736/bjrst.5109.2023
Issue No: Vol. 13, No. 1 (2023)
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