Here we provide an illustrated key to lepidopteran larvae that occur as pests on rice (Oryza) in Malaysia. We are unaware of a published key for this region for this vital commercial crop, and hence provide one based on easily observable features that could be useful for identification, early detection, and pest management by specialists and non-specialists alike (see discussion in Mukerji & Singh 1951, Sri et al. 2010, Timm et al. 2007, Tillmon et al. 2000, Wagener et al. 2004).
Two members of the species Oryctes rhinoceros nudivirus (OrNV) were detected in O. rhinoceros haplotype G beetles collected from an oil palm plantation in Kluang and a wild coconut tree in Batu Pahat (Johor, Malaysia). OrNV strain Kluang comprised 125,794 bp, encoding 125 open reading frames (ORFs), while OrNV strain Batu Pahat comprised 124,925 bp, encoding 126 ORFs.
Kidney stone disease affects 1 - 20% of the general population. At present, the diagnosis of a stone is done using radiography method when noticeable symptoms appeared. We developed a non-invasive quantitative assay for urinary THP, namely ELISA; whereby our previous study and other reports had shown the usefulness of THP as biomarker for kidney stone disease. Since urine is biological fluid that is easily obtainable, this method could be used as a screening assay for kidney stone prior to confirmation with radiography. The ELISA gave assay linearity r(2) > 0.999 within the range of 109 ng/mL to 945 ng/mL THP. Assay precisions were < 4% (C.V.) for repeatability and < 5% (C.V.) for reproducibility. Assay accuracy range from 97.7% to 101.2% at the various THP concentrations tested. Assay specificity and sensitivity were 80% and 86%, respectively. The cut-off points at P < 0.05 were 37.0 and 41.2 mug/mL for male and female, respectively. The assay is cost effective and rapid whereby the cost for assaying each urine sample in duplicate is approximately USD0.35 and within 5 hours, 37 samples can be assayed alongside full range of standards and 3 QC samples in each plate. Furthermore, sample preparation is relatively easy where urine sample was diluted 10 times in TEA buffer. The usability of the ELISA method for diagnosis of kidney stone disease is evaluated with 117 healthy subjects and 58 stone formers.
The CRB (coconut rhinoceros beetle) haplotype was classified into CRB-S and CRB-G, based on the presence of single nucleotide polymorphisms (SNPs) in the mitochondrial cox1 gene. Mitochondrial genomes (mitogenomes) are the most widely used genetic resources for molecular evolution, phylogenetics, and population genetics in relation to insects. This study presents the mitogenome CRB-G and CRB-S which were collected in Johor, Malaysia. The mitogenome of CRB-G collected from oil palm plantations in 2020 and 2021, and wild coconut palms in 2021 was 15,315 bp, 15,475 bp, and 17,275 bp, respectively. The CRB-S was discovered in coconut and oil palms in 2021, and its mitogenome was 15,484 bp and 17,142 bp, respectively. All the mitogenomes have 37 genes with more than 99% nucleotide sequence homology, except the CRB-G haplotype collected from oil palm in 2021 with 89.24% nucleotide sequence homology. The mitogenome of Johor CRBs was variable in the natural population due to its elevated mutation rate. Substitutions and indels in cox1, cox2, nad2 and atp6 genes were able to distinguish the Johor CRBs into two haplotypes. The mitogenome data generated in the present study may provide baseline information to study the infection and relationship between the two haplotypes of Johor CRB and OrNV in the field. This study is the first report on the mitogenomes of mixed haplotypes of CRB in the field.
Four cellulolytic and hemicellulolytic bacterial cultures were purchased from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture (DSMZ) and the American Type Culture Collection (ATCC). Two experiments were conducted; the objective of the first experiment was to determine the optimum time period required for solid state fermentation (SSF) of palm kernel cake (PKC), whereas the objective of the second experiment was to investigate the effect of combinations of these cellulolytic and hemicellulolytic bacteria on the nutritive quality of the PKC. In the first experiment, the SSF was lasted for 12 days with inoculum size of 10% (v/w) on different PKC to moisture ratios. In the second experiment, fifteen combinations were created among the four microbes with one untreated PKC as a control. The SSF lasted for 9 days, and the samples were autoclaved, dried, and analyzed for proximate analysis. Results showed that bacterial cultures produced high enzymes activities at the 4th day of SSF, whereas their abilities to produce enzymes tended to be decreased to reach zero at the 8th day of SSF. Findings in the second experiment showed that hemicellulose and cellulose was significantly (P < 0.05) decreased, whereas the amount of reducing sugars were significantly (P < 0.05) increased in the fermented PKC (FPKC) compared with untreated PKC.
Nine aerobic cellulolytic bacterial cultures were obtained from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture (DSMZ) and the American Type Culture Collection (ATCC). The objectives of this study were to characterize the cellulolytic bacteria and to determine the optimum moisture ratio required for solid state fermentation (SSF) of palm kernel cake (PKC). The bacteria cultures were grown on reconstituted nutrient broth, incubated at 30°C and agitated at 200 rpm. Carboxymethyl cellulase, xylanase, and mannanase activities were determined using different substrates and after SSF of PKC. The SSF was conducted for 4 and 7 days with inoculum size of 10% (v/w) on different PKC concentration-to-moisture ratios: 1 : 0.2, 1 : 0.3, 1 : 0.4, and 1 : 0.5. Results showed that Bacillus amyloliquefaciens 1067 DSMZ, Bacillus megaterium 9885 ATCC, Paenibacillus curdlanolyticus 10248 DSMZ, and Paenibacillus polymyxa 842 ATCC produced higher enzyme activities as compared to other bacterial cultures grown on different substrates. The cultures mentioned above also produced higher enzyme activities when they were incubated under SSF using PKC as a substrate in different PKC-to-moisture ratios after 4 days of incubation, indicating that these cellulolytic bacteria can be used to degrade and improve the nutrient quality of PKC.
Knowledge on the population of genetic structure and ecological behaviour of Apis dorsata from Peninsular Malaysia is needed for effective management and conservation of this species since unsustainable whole solitary low nest cutting for product harvesting is the current common practice here. The analysis of 15 single locus DNA microsatellite markers on samples from 20 solitary nests of A. dorsata showed that while these markers were polymorphic, high intracolonial relatedness existed. Furthermore, in general, slightly negative values of intercolony relatedness (R) among the nests of A. dorsata were found. However, positive values of mean intercolony relatedness were observed between 54 pairs of nests out of 190 possible combinations. The R values among nest pairs 3-4 and 3-5 was higher than 0.50 showing that their queens were half siblings, whereas nest pair 19-20 showed relatedness of 0.95 indicating that the same queen was sampled. The results that we obtained could not conclusively support the hypothesis of this study that the honey hunters in Marang district of Malaysia repeatedly harvest the same nest located at a different site and at a different time during the same honey harvesting season. However, our finding of an appreciable level of intercolonial relatedness between several pairs of nests in this pioneer study indicated that a comprehensive study with a larger sample size of solitary nests found throughout the region would be necessary to provide concrete proof for this novel idea.
A 246-nt variant of Coconut cadang-cadang viroid (CCCVd) has been identified and described from oil palms with orange spotting symptoms in Malaysia. Compared with the 246-nt form of CCCVd from coconut, the oil palm variant substituted C(31)→U in the pathogenicity domain and G(70)→C in the central conserved domain. This is the first sequence reported for a 246-nt variant of CCCVd in oil palms expressing orange spotting symptoms.
Metarhizium anisopliae (Metchnikoff) Sorokin, a pathogenic fungus to insects, infects the subterranean termite, Coptotermes curvignathus Holmgren, a devastating pest of plantation trees in the tropics. Electron microscopy and proteomics were used to investigate the infection and developmental process of M. anisopliae in C. curvignathus. Fungal infection was initiated by germ tube penetration through the host's cuticle as observed at 6 h post-inoculation (PI), after which it elongated into the host's integumental tissue. The colonization process continued as seen from dissemination of blastospores in the hemocoel at 96 h PI. At this time point, the emergent mycelia had mummified the host and forty-eight hours later, new conidia were dispersed on the termites' body surface. Meanwhile, hyphal bodies were observed in abundance in the intercellular space in the host's body. The proteomes of the pathogen and host were isolated separately using inoculated termite samples withdrawn at each PI-time point and analyzed in two-dimensional electrophoresis (2-DE) gels. Proteins expressed in termites showed evidence of being related to cell regulation and the immune response, while those expressed in M. anisopliae, to transportation and fungal virulence. This study provides new information on the interaction between termites and its entomopathogen, with potential utilization for developing future biopesticide to control the termite population.
A reverse transcription loop-mediated isothermal amplification (RT-LAMP) detected Coconut cadang-cadang viroid (CCCVd) within 60 min at 60 °C in total nucleic acid extracted from oil palm leaves infected with CCCVd. Positive reactions showed colour change from orange to green in the reaction mix after the addition of fluorescent reagent, and a laddering pattern band on 2% agarose gel electrophoresis. Conventional RT-PCR with LAMP primers produced amplicons with a sequence identical to the 297-nt CCCVd oil palm variant with the primers being specific for CCCVd and not for other viroids such as PSTVd and CEVd. RT-LAMP was found to be rapid and specific for detecting oil palm CCCVd.