Isozyme procedures for the characterization of germplasm,exemplified by the collection ofLolium perenne L.

The utility of isozymes for the characterization of genetic resources is widely recognised and routinely applied to many species. For theLolium genus a number of different loci and alleles have been identified and used in the characterization of collections and for allied breeding purposes, however confusion has arisen between different sets of results due to the various technical systems applied. Coupled with this is the problem of identification of the products of specific loci and the common designation of alleles at these loci. The present paper provides a synopsis of electrophoretic procedures utilized in a number of European laboratories for the study ofLolium collections together with a nomenclatural code for identifying specific alleles. The origin of this system involved a comparative assessment of a range of tester genotypes ofL. perenne L. Seed stocks of these plants are being regenerated and will be maintained at the gene banks of INRA, Clermont Ferrand, France, CPRO-DLO, Wageningen, Netherlands and at AFRO-IGER, Aberystwyth, Wales and are available for reference purposes.     

Linking laboratory and field responses of fish populations to acidification

To increase understanding of mechanisms by which fish populations respond to water chemistry changes resulting from acidification, it is necessary to link the results of laboratory studies of the effects of pH, Al, and Ca on the survival, growth, and reproduction of individual fish to responses of fish populations in the field. Our framework for achieving this goal is based on the types of data commonly available from both laboratory and field studies. One of the models (PHALCA) in this framework estimates the number of fish surviving as a function of time, given pH, Al, and Ca levels. A second model (FISHEGGS) evaluates the reduction in reproductive potential of a fish population attributable to the effects of pH, Al, and Ca on the survival of young-of-the-year and older fish and on fecundity. Preliminary results from these two models are presented, and the entire framework will be applied and tested over the next year using data for brook trout and lakes in the Adirondacks. The framework and models are a complementary alternative to the statistical analysis of survey data on water chemistry and on presence or absence of a fish species.     

Multiresidue pesticide analysis of agricultural commodities using acetonitrile salt-out extraction, dispersive solid-phase sample clean-up, and high-performance liquid chromatography-tandem mass spectrometry

A multiresidue method analyzing 209 pesticides in 24 agricultural commodities has been developed and validated using the original Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) procedure and high performance liquid chromatography-positive electrospray ionization-tandem mass spectrometry (LC-MS/MS) analysis. Using solvent-only calibration standards (SOCSs) and matrix-matched calibration standards (MMCSs), it was demonstrated that a minimal concentration of 5-10 μg/kg (part per billion, ppb) of analytes in matrix is required for the consistent identification of targeted pesticides with two MRM transitions. Method performance was validated by the precision and accuracy results obtained from fortification studies at 10, 25, 100, and 500 ppb and MMCSs. The method was demonstrated to achieve an average recovery of 100 ± 20% (n = 4) for >75% of evaluated pesticides at the low fortification level (10 ppb) and improved to >84% at the higher fortification concentrations in all 24 matrices. Matrix effects in LC-MS/MS analysis were studied by evaluating the slope ratios of calibration curves (1.0-100 ng/mL) obtained from the SOCSs and MMCSs. Principal component analysis (PCA) of LC-MS/MS and method validation data confirmed that each matrix exerts its specific effect during the sample preparation and LC-MS/MS analysis. The matrix effect is primarily dependent on the matrix type, pesticide type and concentration. Some caution is warranted when using matrix matched calibration curves for the quantitation of pesticides to alleviate concerns on matrix effects. The QuEChERS method with LC-MS/MS was used to identify and quantitate pesticides residues, with concentrations ranging from 2.5 to >1000 ppb in a variety of agricultural samples, demonstrating fitness for screening and surveillance applications.     

Light-responsive cryptochromes from a simple multicellular animal, the coral Acropora millepora

Hundreds of species of reef-building corals spawn synchronously over a few nights each year, and moonlight regulates this spawning event. However, the molecular elements underpinning the detection of moonlight remain unknown. Here we report the presence of an ancient family of blue-light-sensing photoreceptors, cryptochromes, in the reef-building coral Acropora millepora. In addition to being cryptochrome genes from one of the earliest-diverging eumetazoan phyla, cry1 and cry2 were expressed preferentially in light. Consistent with potential roles in the synchronization of fundamentally important behaviors such as mass spawning, cry2 expression increased on full moon nights versus new moon nights. Our results demonstrate phylogenetically broad roles of these ancient circadian clock-related molecules in the animal kingdom.     

Feeding Atlantic salmon diets with plant ingredients during the seawater phase – a full‐scale net production of marine protein with focus on biological performance,welfare, product quality and safety

By feeding Atlantic salmon diets with 64% of the fish oil (FO) replaced by vegetable oil, and with decreasing fishmeal (FM) inclusion levels from 213, 178 and 143 g kg⁻¹ (accumulated level during the seawater phase) in a full‐scale experiment producing 3.1 thousand tonnes fish, no significant negative effects on fish performance, health and product quality were observed. All dietary groups showed, however, moderate intestinal inflammation. Reduced growth and feed efficiency were seen with decreasing fishmeal inclusion levels. Two dietary groups demonstrated net marine protein production, while none of the groups showed net fish production (FIFO ≥1.65) due to the equal low FO inclusion. High plant oil level gave lower fillet level of persistent organic pollutants (POPs) compared with the levels surveyed on the Norwegian market. The study gave predictable incorporation rates of essential n‐3 long‐chain fatty acids in the fillet. Cooked salmon fillet from all dietary groups showed minor differences in sensory quality. Based on the present full‐scale production results, dietary FM inclusion down to 160 g kg⁻¹ (accumulated) during the seawater phase, concurrent to replacing ~70% of the FO with a suitable plant oil, is not regarded to represent any risk to fish performance, health or quality.     

Replacing fish meal with increasing levels of meat and bone meal,soybean meal and corn gluten meal,in diets of juvenile bluegill,Lepomis macrochirus

A 60‐day study was conducted to determine the response of juvenile bluegill Lepomis macrochirus to seven experimental diets, formulated using a blend of alternative protein sources as a replacement for fish meal. Adequate levels (digestible basis) of energy, protein and amino acids were maintained in diets 1–6, whereas slightly lower protein and energy levels were provided in diet 7. Feed cost per tonne ranged from $ 798.9 (diet 1, 550 g Kg^?1 fish meal) to $ 515.8 (diet 6, 0 g kg^?1 fish meal), or to $ 507.2 (diet 7, 0 g Kg^?1 fish meal). Three commercial diets were included in the study as reference diets: a high‐energy and a low‐energy trout diet, as well as a catfish diet. Quintuplicate bluegill groups (~22 g, n = 10 fish group^?1) were fed the experimental diets twice daily to apparent satiation. No major differences in feed consumption, feed efficiency and growth rates were detected among the bluegill groups fed the experimental diets. Trout diets generally produced higher fish fat deposition, whereas the catfish diet produced a poorer fish growth rate relative to the experimental diets. Under the reported conditions, results indicate diet 6, comprising predominantly soybean meal and porcine meat and bone meal, to be the most economical diet for juvenile bluegill.