Phenolics and Antioxidative Activities in Narrow-Leafed Lupins (Lupinus angustifolius L.)

Eight lupin (Lupinus angustifolius L.) genotypes grown at four locations in south central Alberta in 2004 were evaluated for variability in phenolic constituents and antioxidant activity measured by a photochemiluminescence assay. Genotype was the main source of variation for content of phenolic compounds and antioxidant activities. Phenolic compounds in genotypes varied minimally from 11.9 to 14.7 mg catechin equivalent and 4.15 to 4.95 mg rutin equivalent g⁻¹ lupin for total phenolic and flavonoid contents, respectively. Lupin genotypes exhibited weak antioxidant activity based on water–soluble substances (ACW) of 0.54 to 1.07 μmole Trolox equivalent antioxidant capacities (TEAC)/g with lag time ranging from 70 to 153 s and an antioxidant index of 6.7 to 14.5 and 1.9 to 3.3 μmole TEAC/g based on measurements of lipid-soluble substances (ACL). Antioxidant activity of lupin genotypes was not related to phenolic contents of seeds.     

Double haploids,markers and QTL analysis in vegetable brassicas

Double haploid (DH) plants of Brassica spp. can be produced via anther culture or culture of microspores. This paper reviews the uses of double haploids in crop improvement research in vegetable brassicas (B. oleracea). Applications of DH lines are described for breeding; construction of linkage maps; genetic analysis of quantitative traits and capturing genetic variation. The advantages and disadvantages of DH lines are discussed     

The physiological response of Atlantic salmon, Salmo salar L., to a single experimental challenge with sea lice, Lepeophtheirus salmonis

The sea louse, Lepeophtheirus salmonis , is an ectoparasitic copepod of Atlantic salmon, Salmo salar L., capable of causing severe damage. This study was conducted to examine the physiological response of salmon to the stress of sea lice infestation. Smoltified salmon were acclimatized in 30‰ saltwater and exposed to high levels of lice infestation. The number of copepods per fish ranged from 15 to 285, with a mean of 106. The infested salmon were sampled six times over the 29-d experimental duration and examined for alterations in the primary and secondary stress indicators, including plasma concentrations of cortisol, glucose, electrolytes, thyroid hormones T3 and T4, as well as the haematocrit level. The results were examined for correlations between the stress indicators, the number of copepods per fish and the life stage of the copepods. The presence of L. salmonis elevated stress indicators in relation to the specific sea lice stage. By day 21, both cortisol (mean 63.1 nmol L−1 controls: 179.8 nmol L−1 for parasitized) and glucose (mean 3.545 mmol L−1 controls: 4.567 mmol L−1 for parasitized) levels were significantly increased due to the presence of the lice. This was believed to be a direct result of the sea lice development into the larger life stages, thus increasing the level of host damage.     

Normal and aberrant tissue distribution of Loma salmonae (Microspora) within rainbow trout, Oncorhynchus mykiss (Walbaum), following experimental infection at water temperatures within and outside of the xenoma-expression temperature boundaries

Temperatures above 20 °C or below 9 °C interrupt the life cycle of the gill intracellular microsporidian parasite Loma salmonae (Microspora) prior to sporogony, inhibiting the production of xenomas. This study intended to characterize this life-cycle failure. Juvenile rainbow trout, Oncorhynchus mykiss (Walbaum), were experimentally infected with L. salmonae spores, and the effect of water temperature on the progress of infection, as determined by polymerase chain reaction, was compared for fish held at water temperatures of 5, 15 and 21 °C. At 15 °C, parasite DNA was first detected in the heart (3 days post-exposure [PE]), and then in the gills and spleen (2 weeks PE). Branchial xenomas developed by week 4 PE. In contrast, at 5 °C, the arrival of the parasite in the heart was delayed until 7 days PE. However, even though parasite DNA was detected in the gills at 7 days PE, xenomas failed to form in the gill, and by week 4 PE, parasite DNA was no longer detected. In fish held at 21 °C, parasite DNA was detected in the heart, gills and spleen by 3 days post-infection, and similar results were observed at 7 days PE. Xenomas also failed to form in these fish and parasite DNA was no longer detected by week 2 PE. Within the range of temperatures tested in this study, spore germination and delivery of their DNA into the host through the intestinal wall was not blocked by temperature. At 5 or 21 °C, migration to the heart and gills occurred, but at aberrant periods of time. The normal life cycle of L. salmonae may depend on the completion of relatively lengthy, but yet unknown, stages of development within the heart, prior to reaching the gill. This development may be adversely affected by temperature, and explain the temperature limits of this parasite.     

Preference for and performance of some Australian native plants grown as hedges

Indigenous and other native plants are commonly restricted to informal or naturalistic designed landscapes. This research project investigates the use of native plants as a formal landscape element – the hedge. A multidisciplinary approach was used with distinct horticultural and social science components. The first study explored the response of 14 native and one exotic species to hedging every 4 months. Digital imaging techniques were used to measure changes in growth, density and canopy distribution. All species responded well to hedging, greatly increasing in density. Significant differences in growth rates and shoot regrowth patterns were recorded between the species. Some hedges grown from genetically diverse plant material had noticeable morphological variations and would be more suited to use as informal hedges, however growth rates were found to be a much better predictor of hedging performance than genetic uniformity. A second study explored gardeners’ (n=162) preference for these native hedges. Photomontages were created of the hedges grown in the horticultural experiment and a photo-questionnaire distributed to several groups of gardeners. The preference results showed that many gardeners did like some Australian plants used as hedges. Significant differences in preference were found between species. A principal components analysis found that factors positively affecting preference for hedges included neatness, foliage colour (green and grey), presence of flowers and the absence of visible woody stems. In general, genetically diverse hedges were slightly less preferred than genetically uniform hedges, but some genetically diverse hedges were highly preferred. Personal style preferences based on gardeners’ expressed gardening behaviour were also observed, with grey and softer hedges preferred by those participants with low-maintenance, drought tolerant or native gardens.     

Effects of formalin, chloramine-T, and low salinity dip on the behavior and hemolymph biochemistry of the American lobster.

The purpose of this research was to investigate the salinity and formalin sensitivity of a ciliate parasite (Anophryoides haemophila) of the American lobster (Homarus americanus), and to examine the target-animal (lobster) safety of chemical-bath treatments involving low salinity, formalin, or chloramine-T that could be used to control this parasite in lobster pounds. "Bumper car" disease, caused by An. haemophila, is an important concern to lobster pound operators in eastern North America, because of the implicated lobster mortality rate and the general lack of preventive and therapeutic intervention regimes. We determined, using an in vitro method, that formalin at 50 mg/L, or low salinity at 8.0 parts per thousand (ppt) for 1 hour killed 100% of the parasites. When healthy lobsters were exposed to formalin at 200 mg/L, there were no negative behavioral responses and no significant differences in a panel of hemolymph biochemical indices. Similar results occurred when lobsters were exposed to chloramine-T, a common finfish therapeutic agent for topical bacteria and protozoa, at 10 mg/L for 1 hour. The low salinity treatment (8.0 ppt) resulted in significant adverse changes in lobster behavior and biochemical indices; however, these changes did not persist for more than 1 week after treatment ended. Although these treatments are unlikely to kill parasites that have already invaded the lobster carapace, they should be effective in reducing parasite loads on the gill and carapace surface of the lobster and in the environment of the impoundment housing.