Formulation of vegetable fat pellets with pheromone and Beauveria bassiana to control the larger grain borer,Prostephanus truncatus (Horn)

The use of hydrogenated rapeseed oil as a carrier for conidia of the entomopathogenic fungus Beauveria bassiana (Bals) Vuill was investigated as part of a research programme on the control of the larger grain borer, Prostephanus truncatus (Horn). Melting the oil, which is solid at temperatures below 32 °C, allows the incorporation of materials such as aggregation pheromones and conidia; sudden cooling produces solid fat pellets. In attraction tests conducted with pellets containing P truncatus aggregation pheromone, significantly higher numbers of beetles were attracted to pellets containing pheromone at a concentration of 4 ml litre⁻¹ compared to control pellets for at least four weeks when held in Petri dishes in the laboratory and for at least six weeks when pellets held in insect traps were exposed to outside conditions. The attraction was retained over a period of storage in glass bottles; pellets stored in the freezer or incubator (at −10 °C or 27 °C) attracted beetles according to the pheromone level for the duration of the work (14 and 13 months respectively). When pheromones and conidia were incorporated into the same pellets they could be stored in a freezer or refrigerator retaining over 80% viability after 51 weeks; those stored in an incubator at 27 °C showed significantly lower germination at 20.7–27.2% after the same time. There was an indication that the pheromone caused a slight reduction in the viability of conidia, although this may have been just a slight delay in the speed of germination. Rapid dose transfer from pellets with conidia with and without the addition of pheromone was demonstrated. Insects were exposed to pellets for 24 hours and 96–100% mortality was observed in treatments containing conidia within six days of exposure. © 1999 Society of Chemical Industry     

De Novo Next Generation Sequencing of Plant Genomes

The genome sequencing of all major food and bioenergy crops is of critical importance in the race to improve crop production to meet the future food and energy security needs of the world. Next generation sequencing technologies have brought about great improvements in sequencing throughput and cost, but do not yet allow for de novo sequencing of large repetitive genomes as found in most crop plants. We present a strategy that combines cutting edge next generation sequencing with “old school” genomics resources and allows rapid cost-effective sequencing of plant genomes.     

Measuring responses of harbour seals to potential aversive acoustic mitigation signals using controlled exposure behavioural response studies

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Post‐disturbance haulout behaviour of harbour seals

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Effects of dietary canola oil level on growth, fatty acid composition and osmoregulatory ability of juvenile fall chinook salmon (Oncorhynchus tshawytscha)

This study assessed refined canola oil (CO) as a supplemental dietary lipid source for juvenile fall chinook salmon, Oncorhynchus tshawytscha, parr with respect to possible effects on their growth and osmoregulatory performance and body composition. Diets with equal protein ( 57%) and lipid ( 19%) content (dry weight basis) were supplemented with lipid from either anchovy oil (AO) or CO with AO so that CO comprised 0 (0CO), 11% (11CO), 22% (22CO), 33% (33CO), 43% (43CO) or 54% (54CO) of the dietary lipid content. Triplicate groups of juvenile chinook salmon were fed their prescribed diets for 104 days in freshwater (FW) and 31 days in seawater (SW) after a 4-day transition period. Dietary fatty acid compositions reflected the different proportions of AO and CO in the supplemental lipid. Diet treatment had no effect on fish growth, feed intake, feed efficiency, protein utilization, fish mortality or terminal whole body water and ash percentages. Whole body lipid percentages were higher in 11CO and 43CO fish than in 33CO fish and in 11CO fish versus 22CO fish. Whole body protein percentages were highest in 33CO, 43CO and 54CO fish and lowest in 0CO and 22CO fish. Terminal whole body fatty acid compositions were influenced strongly by the dietary fatty acid compositions. Haematocrit and muscle water percentages were not affected consistently and plasma Na⁺ and Cl⁻ concentrations were unaffected by diet treatment in FW or 24-h seawater challenges during FW residency. Also, diet treatment had no effect on the physiological parameters after SW residency. We conclude that dietary treatment had no effect on fish growth performance under our experimental conditions. Also, the dietary inclusion of CO neither facilitated nor impaired the transfer of chinook salmon parr to seawater. Thus, CO was found to be an excellent and cost-effective source of supplemental dietary lipid for culture of juvenile fall chinook salmon during freshwater residency.     

Responsiveness of fish mass–abundance relationships and trophic metrics to flood disturbance,stream size,land cover and predator taxa presence in headwater streams

Characterisation of food webs, by summarising energy transfer and trophic relationships, allows more functional measurement of ecosystems and may reveal threats (e.g., land‐cover change) in sensitive environments that are not obvious from conventional biomonitoring. However, typical methods used to achieve this are time‐consuming and expensive. Therefore, we tested the usefulness of fish‐focused food‐web proxies as functional measures, specifically mass–abundance relationships of fish assemblages and stable isotope (SI)‐derived metrics in headwater stream reaches. These metrics have been trialled before for similar use in other settings, but have yielded varying results, and have not been employed in tandem in temperate freshwaters. Sampling reaches (N = 46) were spread across a variety of streams, and the effects of habitat predictors at multiple scales on metrics were assessed using model selection. We found that habitat size positively correlated with food‐chain lengths in streams, possibly because of increased abundance of fish at multiple trophic levels in habitats with more space. Additionally, flood disturbance was negatively associated with fish mass–abundance and carbon range, likely due to the harshness of flood‐prone streams. Riparian land‐cover variables were correlated with multiple metrics, indicating the importance of terrestrial–aquatic linkages. Additionally, variations in all metrics were influenced by the presence of native, predatory longfin eels. Overall, we conclude that mass–abundance relationships and SI‐derived metrics are sensitive to drivers of trophic organisation and likely reflect processes occurring at multiple spatial scales in freshwaters. Thus, these metrics could be an insightful monitoring tool for managers because they reflect functional measures of aquatic ecosystems.     

Methionine Requirement for Juvenile White Seabass,Atractoscion nobilis,Using Nonlinear Models

Two trials were conducted to estimate the methionine (Met) requirement of juvenile white seabass, Atractoscion nobilis. Diets were formulated to contain 40% crude protein, 10% lipids, and 0.51% cysteine. Graded levels of dl ‐Met were added to create seven diets with dietary Met levels ranging from 0.72 to 0.98%, and nine diets ranging from 0.64 to 1.28% Met in Trials A and B, respectively. Thermal‐unit growth coefficient was fitted to dietary Met levels to estimate the Met requirement using the saturation kinetic model (SKM), the quadratic model (QM), or the broken quadratic model (BQM). The 95% confidence interval (CI) was estimated through the iterative fitting process for the BQM and using a bootstrapping approach for the QM and SKM. In Trial A, the three models estimated the requirement between 0.88 and 1.08%, with wide CI. In Trial B, precisions of the requirement estimates by the SKM and BQM were significantly improved compared with Trial A, though BQM evidently overestimated the requirement. SKM provided the best fit; hence, we conclude that the Met requirement for juvenile white seabass is 0.88% (95% CI: 0.80–1.08%) in the presence of 0.51% cysteine. This estimate provides valuable basis for the formulation of practical diets for juvenile white seabass.     

Oxidative damage in forage rape (Brassica napus L.) seeds following heat stress during seed development

A short period (240°C hr; Tb = 25°C) of heat stress (30°C day/25°C night) during forage rape (Brassica napus L.) seed development or at seed physiological maturity can reduce seed vigour, but the extent of oxidative damage associated with this short heat stress was not known. Heat-stressed seeds were assessed for malondialdehyde (MDA) content, hydrogen peroxide (H₂O₂) accumulation, antioxidant enzyme activity, adenylate energy charge and seed ultrastructural integrity, and compared with that of non-heat-stressed seeds. Heat stress increased both MDA content and H₂O₂ accumulation by 35%–50%, reduced antioxidant enzyme activity by between 12% and 67%, and significantly reduced adenosine energy charge. Transmission electron microscope images showed clear evidence of seed deterioration in heat-stressed seeds, including ruptures in cell wall and plasma membranes, fused lipid bodies and damaged mitochondria. Heat stress at physiological maturity caused more oxidative damage than the same heat stress during seed development. Seed vigour decreased as H₂O₂ accumulation increased and antioxidant enzyme activity decreased, but no direct relationship between lipid peroxidation and seed vigour was established. The extent of damage resulting from even shorter periods of heat stress (<240°C hr) before or at seed physiological maturity requires investigation.     

Volatile Compounds of Dry Beans (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.)

Volatile compounds of uncooked dry bean (Phaseolus vulgaris L.) cultivars representing three market classes (black, dark red kidney and pinto) grown in 2005 were isolated with headspace solid phase microextraction (HS-SPME), and analyzed with gas chromatography mass spectrometry (GC-MS). A total of 62 volatiles consisting of aromatic hydrocarbons, aldehydes, alkanes, alcohols and ketones represented on average 62, 38, 21, 12, and 9 x 10(6) total area counts, respectively. Bean cultivars differed in abundance and profile of volatiles. The combination of 18 compounds comprising a common profile explained 79% of the variance among cultivars based on principal component analysis (PCA). The SPME technique proved to be a rapid and effective method for routine evaluation of dry bean volatile profile.