Genetic diversity of Ganoderma in oil palm plantings

Isolates of Ganoderma spp. associated with basal stem rot of oil palm were obtained by sampling from two palm plantings in Malaysia. Members of a subset of these were compared using a combination of somatic incompatibility and molecular genetic analyses. Incompatibility interactions between heterokaryons in culture indicated that Ganoderma generally occurred as numerous distinct strains, with compatible strains usually confined to individual palms. Analysis of restriction fragment length polymorphisms (RFLPs) in presumptive mitochondrial DNA (mtDNA) revealed heterogeneity among isolates from neighbouring palms, and from within individual palms. The combination of mtDNA variability and somatic incompatibility suggests that Ganoderma BSR does not spread by direct root-to-root contact between palms. The results may indicate infection spread through basidiospore dispersal or through contact with a heterogeneous long-term residual inoculum in debris.     

Utilisation of unbleached kenaf fibers for the preparation of magnetic paper

Unbleached kenaf fibers were selected for the manufacture of magnetic paper using chemical coprecipitation method. This method involved precipitation and loading of nano-sized ferrite particles into the lumen of the kenaf fibers. While the degree of loading depended on both the degree of agitation and temperature of the coprecipitation, the thermal stability of the produced magnetic paper depended mainly on the temperature. The magnetic particles deposited on the fiber surface had detrimental effects on the strength of the produced paper. The coercivity value of the magnetic paper depended on the type of ferrite produced from the coprecipitation.     

Understanding of relationships between ground cover and rat abundances: An integrative approach for management of the oil palm agroecosystem

Ground cover is an essential element in the selection of habitats by small mammals. It provides shelter, foraging opportunities and a hiding place from predators. In oil palm plantations rodents are abundant yet the relationships between ground cover structure and rats are not well understood. Plantation management emphasizes maximisation of oil palm yield by reducing rat damage and competition from weeds, typically through chemical control. This study examined the relationships between ground cover, including undergrowth and frond piles, and rat abundance. Rat trapping and vegetation assessment were conducted simultaneously in five study plots in the Labu Estate, Negeri Sembilan, Malaysia. Over 21,000 trap-nights 1190 individual rats were captured and these data were analysed using spatial analysis by distance indices (SADIE). No significant clustering of rats was observed within any plot over time. Redundancy analyses suggested that the overall occurrence of rats, especially Rattus argentiventer, was positively correlated with vegetation cover and height. This implies that habitat complexity is important to rats, even in a relatively simple agroecosystem. Results of the SADIE analyses were inconsistent, perhaps due to highly variable management practices in the plantations. The findings from this study suggest that using an integrated approach in the control of both weeds and rats in oil palm plantations may maximise the benefits from weeding while reducing the production loss due to rats and the need for chemical control of rats.     

Humus-Rich Compost Increases Lettuce Growth, Nutrient Uptake, Mycorrhizal Colonisation, and Soil Fertility

Sandy soils, typical of Australia's west, either have little or no habitat protection for microbes including arbuscular mycorrhizal (AM) fungi, which are essential for nutrient cycling. To minimize this problem, the application of organic matter, such as humus-rich composts, is necessary during vegetable crop production. This study aimed at determining the effects of humus-rich composts on either indigenous or inoculated AM fungal colonisation in roots, lettuce (Lactuca sativa L. var. Quechua) growth, and soil fertility improvement. Four different humus-rich composts with varying humus contents were applied at the same standard rate to lettuce grown under glasshouse conditions for 10 weeks after sowing and compared with two low-humus composts and non-amended soil (control). Humus-rich composts significantly increased lettuce shoot growth, root growth, and AM fungal colonisation in roots. Humus contents in the composts were also correlated with lettuce shoot and root growth. Soil dissolved organic carbon, microbial biomass carbon, and fertility were increased with the application of humus-rich composts. These humus-rich composts, especially the compost of higher humic acid with and without AM inoculation, might have a significant role in sustainable vegetable production, for example lettuce growth. Overall, the results indicate that supplementation with humus-rich compost is highly beneficial to enhance soil fertility and potentially maintain the sustainability of vegetable production.     

Screening of microfilaricidal effects of plant extracts against Dirofilaria immitis

Canine dirofilariasis is a common tropical parasitic disease of companion animals, caused by infestation of Dirofilaria immitis filarids within the pulmonary arteries and extending into the right heart. Increased reports of adverse reactions elicited by current microfilaricidal agents against D. immitis such as neurological disorders, circulatory collapse and potential resistance against these agents, warrant the search for new agents in forms of plant extracts. The use of plant extracts in therapeutic medicine is commonly met with scepticism by the veterinary community, thus the lack of focus on its medical potential. This study evaluated the presence of microfilaricidal activities of the aqueous extracts of Zingiber officinale, Andrographis paniculata and Tinospora crispa Miers on D. immitisin vitro at different concentrations; 10 mg/ml, 1 mg/ml, 100 μg/ml, 10 μg/ml and 1 μg/ml within 24 h, by evaluation of relative microfilarial motility as a measure of microfilaricidal activity. All extracts showed microfilaricidal activity with Z. officinale exhibiting the strongest activity overall, followed by A. paniculata and T. crispa Miers. It is speculated that the microfilaricidal mechanism exhibited by these extracts is via spastic paralysis based upon direct observation of the microfilarial motility.     

Monitoring of sewage pollution in the surface sediments of coastal ecosystems using linear alkylbenzenes (LABs) as molecular markers

Journal of Soils and Sediments - Molecular organic markers are an effective tool to detect the adverse effects of anthropogenic inputs in the aquatic environment. Linear alkylbenzenes (LABs) are...     

Preparation, Characterization, and Adsorption Behavior of Cu(II) Ions onto Alkali-Treated Weed (Imperata cylindrica) Leaf Powder

The adsorption of Cu(II) ions by sodium-hydroxide-treated Imperata cylindrica (SoHIC) leaf powder was investigated under batch mode. The influence of solution pH, adsorbent dosage, shaking rate, copper concentration, contact time, and temperature was studied. Copper adsorption was considered fast as the time to reach equilibrium was 40–90 min. Several kinetic models were applied and it was found that pseudo-second-order fitted well the adsorption data. In order to understand the mechanism of adsorption, spectroscopic analyses involving scanning electron microscope (SEM) coupled with energy-dispersive spectroscopy (EDS) and Fourier transform infrared (FTIR) spectrophotometer were carried out. Ion exchange was proven the main mechanism involved as indicated by EDS spectra and as there was a release of light metal ions (K⁺, Na⁺, Mg²⁺, and Ca²⁺) during copper adsorption. Complexation also occurred as demonstrated by FTIR spectra involving hydroxyl, carboxylate, phosphate, ether, and amino functional groups. The equilibrium data were correlated with Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models. Based on Langmuir model, the maximum adsorption capacity was recorded at the highest temperature of 310 K, which was 11.64 mg g^?1.     

Evaluation of the Combined Cr(VI) Removal Capacity of Sawdust and Sawdust-Immobilized Acinetobacter haemolyticus Supplied with Brown Sugar

The purpose of this study is to evaluate the combined Cr(VI) removal capacities of nonliving (untreated rubber wood sawdust, URWS) and living biomass (URWS-immobilized Acinetobacter haemolyticus) in a continuous laboratory scale downward-flow two column system. Synthetic solutions of Cr(VI) between 237 and 320 mg L^?1 were mixed with 1 g L^?1 brown sugar in a nonsterile condition. Final Cr(VI) of between 0 and 1.6 mg L^?1 indicate a Cr(VI) removal capacity of 99.8–100%. The bacterial Cr(VI) reduction capacity increased with column length. This study shows the feasibility of using the two column system consisting of living (bacteria) and nonliving biomass (URWS) as a useful alternative treatment for Cr(VI) contamination in the aqueous system.     

Outbreaks of foot-and-mouth disease in Peninsular Malaysia from 2001 to 2007

This is a retrospective study of the outbreaks of foot-and-mouth disease (FMD) in Peninsular Malaysia between 2001 and May 2007. In total, 270 outbreaks of FMD were recorded. Serotype O virus (89.95 %) and serotype A (7.7 %) had caused the outbreaks. Significant differences on the occurrence of FMD were found between the years (t?=?5.73, P?=?0.000, df?=?11), months (t?=?4.7, P?=?0.000, df?=?11), monsoon season (t?=?2.63, P?=?0.025, df?=?10) and states (t?=?4.84, P?=?0.001, df?=?10). A peak of outbreaks observed in 2003 could be due to increased animal movement and the other peak in 2006 could be due to a compromised FMD control activities due to activities on the eradication of highly pathogenic avian influenza. Cattle (86 % of outbreaks) suffered the most. However, no difference in disease occurrence between species was observed. The populations of cattle (r?=?0.672, P?=?0.023) and sheep (r?=?0.678, P?=?0.022) were significantly correlated with occurrence of FMD. Movement of animals (66 % of outbreaks) was the main source for outbreaks. A combination of control measures were implemented during outbreaks. In conclusion, the findings of this study show that FMD is endemic in Peninsular Malaysia, and information gained could be used to improve the existing control strategy.     

Growth,phosphorus uptake,and rhizosphere microbial‐community composition of a phosphorus‐efficient wheat cultivar in soils differing in pH

In a pot experiment, the P‐efficient wheat (Triticum aestivum L.) cultivar Goldmark was grown in ten soils from South Australia covering a wide range of pH (four acidic, two neutral, and four alkaline soils) with low to moderate P availability. Phosphorus (100 mg P kg^–1) was supplied as FePO₄ to acidic soils, CaHPO₄ to alkaline, and 1:1 mixture of FePO₄ and CaHPO₄ to neutral soils. Phosphorus uptake was correlated with P availability measured by anion‐exchange resin and microbial biomass P in the rhizosphere. Growth and P uptake were best in the neutral soils, lower in the acidic, and poorest in the alkaline soils. The good growth in the neutral soils could be explained by a combination of extensive soil exploitation by the roots and high phosphatase activity in the rhizosphere, indicating microbial facilitation of organic‐P mineralization. The plant effect (soil exploitation by roots) appeared to dominate in the acidic soils. Alkaline phosphatase and diesterase activities in acidic soils were lower than in neutral soils, but strongly increased in the rhizosphere compared with the bulk soil, suggesting that microorganisms contribute to P uptake in these acidic soils. Shoot and root growth and P uptake per unit root length were lowest in the alkaline soils. Despite high alkaline phosphatase and diesterase activities in the alkaline soils, microbial biomass P was low, suggesting that the enzymes could not mineralize sufficient organic P to meet the demands of plants and microorganisms. Microbial‐community composition, assessed by fatty acid methylester (FAME) analysis, was strongly dependent on soil pH, whereas other soil properties (organic‐C or CaCO₃ content) were less important or not important at all (soil texture).