Summerland Research and Development Centre
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Top-cited papers from Summerland Research and Development Centre
The antioxidant activities and total phenolics of 28 plant products, including sunflower seeds, flaxseeds, wheat germ, buckwheat, and several fruits, vegetables, and medicinal plants were determined. The total phenolic content, determined according to the Folin−Ciocalteu method, varied from 169 to 10548 mg/100 g of dry product. Antioxidant activity of methanolic extract evaluated according to the β-carotene bleaching method expressed as AOX (Δ log A470/min), AA (percent inhibition relative to control), ORR (oxidation rate ratio), and AAC (antioxidant activity coefficient) ranged from 0.05, 53.7, 0.009, and 51.7 to 0.26, 99.1, 0.46, and 969.3, respectively. The correlation coefficient between total phenolics and antioxidative activities was statistically significant. Keywords: Antioxidant activity; phenolics; medicinal plants; oilseeds; buckwheat; vegetables; fruits; wheat products
To investigate the role of jasmonate in the defense of plants against fungal pathogens, we have studied a mutant of Arabidopsis, fad3-2 fad7-2 fad8, that cannot accumulate jasmonate. Mutant plants were extremely susceptible to root rot caused by the fungal root pathogen Pythium mastophorum (Drechs.), even though neighboring wild-type plants were largely unaffected by this fungus. Application of exogenous methyl jasmonate substantially protected mutant plants, reducing the incidence of disease to a level close to that of wild-type controls. A similar treatment with methyl jasmonate did not protect the jasmonate-insensitive mutant coi1 from infection, showing that protective action of applied jasmonate against P. mastophorum was mediated by the induction of plant defense mechanisms rather than by a direct antifungal action. Transcripts of three jasmonate-responsive defense genes are induced by Pythium challenge in the wild-type but not in the jasmonate-deficient mutant. Pythium species are ubiquitous in soil and root habitats world-wide, but most (including P. mastophorum) are considered to be minor pathogens. Our results indicate that jasmonate is essential for plant defense against Pythium and, because of the high exposure of plant roots to Pythium inoculum in soil, may well be fundamental to survival of plants in nature. Our results further indicate that the fad3-2 fad7-2 fad8 mutant is an appropriate genetic model for studying the role of this important signaling molecule in pathogen defense.
Abstract Flaxseed is emerging as one of the key sources of phytochemicals in the functional food arena. In addition to being one of the richest sources of α‐linolenic acid oil and lignans, flaxseed is an essential source of high‐quality protein and soluble fibre and has considerable potential as a source of phenolic compounds. The implications of diets containing flaxseed or its components for human nutrition and disease prevention are analysed in this paper. Results of the first meta‐analysis examining the relationship between intake of flaxseed or its components and risk reduction of disease in humans is presented. Some areas of potential opportunities and impact of using flaxseed or its components in the diet are highlighted. For the Department of Agriculture and Agri‐Food, Government of Canada. © Minister of Public Works and Government Services Canada 2001. Published for SCI by John Wiley & Sons, Ltd.
Changes in phenolics (anthocyanins, flavonols, tartaric esters, and total phenolics) during ripening of grapes and in phenolics and color during vinification and aging of Cabernet Franc, Merlot, and Pinot Noir wines were studied. Anthocyanins in grape skins showed variations in accumulation pattern, concentration, and distribution depending on variety and to a lesser extent on season. During vinification, colorless phenolics increased during alcoholic fermentation, reached maximum values at pressing, and remained stable during malolactic fermentation and subsequent storage. Anthocyanins and color density, on the other hand, increased during the early stages of alcoholic fermentation, reached maximum values 2-3 days after the start of fermentation, decreased during malolactic fermentation, and slowly declined during subsequent storage. Viticultural practices that increased cluster sun exposure generally led to higher phenolics and color density of wines, whereas changing yeasts used for fermentation had minimal effects.
Eggs from ISA-White and ISA-Brown hens between 28 and 59 wk of age were stored for up to 10 d to produce a sample of 5,763 eggs differing in the three major determinants of albumen quality. Eggs from ISA-Brown hens were larger and had less yolk, more albumen, and a greater percentage of shell than those from ISA-White hens. Egg size increased with increasing age of the hen, although more for the ISA-White hens than the ISA-Brown hens, and the yolk increased more in size than did the shell and albumen. During storage, albumen weight decreased and yolk weight increased slightly. The height of the inner thick albumen of eggs from ISA-White hens was greater than that of eggs from ISA-Brown hens, and it decreased as the hen age increased and with increasing time in storage. The pH of the albumen was not different between strains, and the effect of hen age was small, but it increased with time in storage. Regression coefficients of the height of the inner thick albumen on the weight of the egg were between -0.058 and 0.102, showing that the fixed regression of 0.05-mm albumen height per gram of egg implied by the Haugh unit is wrong. The statistical association between albumen pH and egg weight was very low. If albumen quality is being used as a measure of freshness, then the albumen height is biased by the strain and age of hen, whereas the albumen pH is not.
Eggs from 31-wk-old ISA-White and ISA-Brown hens were sampled immediately after lay and after periods of storage of 1, 3, 5, and 10 d at room temperature. Longer periods of storage resulted in lower albumen weight and albumen height and higher albumen pH. Eggs from ISA-Brown hens had more albumen and shell than those from ISA-White hens, likely due to differences in selection history rather than due to pleiotropic effects of eggshell color. Within each line and storage period, the egg weight was more closely associated with albumen weight than with yolk or shell weight. The albumen height of eggs from ISA-Brown hens was lower than that of ISA-White hens at all storage times, but the albumen pH was not affected by the strain. Albumen height and albumen pH were statistically unrelated in fresh eggs, but the association became larger as the storage period increased, suggesting that albumen height measures factors that are present when the egg is laid and changes during storage, whereas albumen pH measures only the effect of storage.
Species in the Botryosphaeriaceae have a cosmopolitan distribution, and occur on a wide range of annual and perennial hosts including grapevines. To date, morphological and taxonomic studies, as well as analyses of nucleotide sequences of multiple genes, have allowed the identification of at least 21 different species in the Botryosphaeriaceae occurring in grapevines worldwide. Grapevine disease symptoms caused by members of this family include leaf spots, fruit rots, shoot dieback, bud necrosis, vascular discoloration of the wood, and perennial cankers, and their current status as pathogens is reviewed. Additionally, the disease name Botryosphaeria dieback is proposed here to describe the different grapevine trunk disease symptoms caused by species of Botryosphaeriaceae. Much has been written during the last decade about the association between species in the Botryosphaeriaceae and grapevine trunk diseases, which has contributed to a better understanding of the role that these fungal taxa play in grapevine diseases. Although virulence has been shown to vary between species and isolates of the same species in different countries, these fungi have become well-recognized as important grapevine pathogens worldwide. Latest and novel findings from studies conducted in different countries, on disease etiology and species distribution, epidemiology and biology are discussed. Much progress has been achieved in the development and implementation of novel diagnostic and detection techniques.Vineyard sanitation techniques, as well as chemical, biological, and cultural control strategies available at the present time to reduce the infection caused by botryosphaeriaceous fungi, are presented in this review.
This study tested whether providing cows a 4-wk period on pasture would improve gait and change lying behavior. Eighteen groups, each of 4 lactating Holstein cows initially housed in a freestall barn, were assigned to either continued housing in the same freestall barn, or moved to pasture to provide changes in both physical environment and diet. To assess lameness, gait scores (1 to 5) were recorded weekly for 4 wk. Gait improved by an average of 0.22 units/wk for those cows kept on pasture. We also recorded 4 specific gait attributes (head bob, back arch, tracking up, and reluctance to bear weight evenly on all 4 hooves), and found that the latter 2 attributes also improved during the pasture period. Improved gait for cows on pasture was not because of increased lying times. Cows on pasture actually spent less time lying down than cows kept indoors (10.9 vs. 12.3 h/d), although this lying time was spread over a larger number of bouts (15.3 vs. 12.2 bouts). Cows housed on pasture also lost more weight and produced less milk relative to cows in freestalls, likely because of reduced nutrient intake. These results indicate that a period on pasture can be used to help lame cattle recover probably because pasture provides a more comfortable surface upon which cows stand, helping them to recover from hoof and leg injuries.
Acquisition and transmission by an insect vector is central to the infection cycle of the majority of plant pathogenic viruses. Plant viruses can interact with their insect host in a variety of ways including both non-persistent and circulative transmission; in some cases, the latter involves virus replication in cells of the insect host. Replicating viruses can also elicit both innate and specific defense responses in the insect host. A consistent feature is that the interaction of the virus with its insect host/vector requires specific molecular interactions between virus and host, commonly via proteins. Understanding the interactions between plant viruses and their insect host can underpin approaches to protect plants from infection by interfering with virus uptake and transmission. Here, we provide a perspective focused on identifying novel approaches and research directions to facilitate control of plant viruses by better understanding and targeting virus-insect molecular interactions. We also draw parallels with molecular interactions in insect vectors of animal viruses, and consider technical advances for their control that may be more broadly applicable to plant virus vectors.
Abstract The kinetics of NH + 4 adsorption and desorption were investigated on the natural zeolite clinoptilolite to ascertain its ability to adsorb and release the important plant nutrient N in its NH + 4 form at various pH values and initial NH + 4 concentrations. Kinetics of NH + 4 adsorption were evaluated on the samples using solutions containing 140.1, 280.2, 560.4, and 840.6 mg L −1 of NH + 4 ‐N at pH 4, 5, 6, and 7, equilibrated for 5, 10, 15, 20, 30, 45, 60, 75, 90, and 120 min. Samples for NH + 4 desorption were equilibrated with 70.1, 280.2, 560.4, and 1401 mg L −1 NH + 4 ‐N solution at pH 4, 5, 6, and 7 for 2.5 h, and adsorbed NH + 4 extracted with 2 M KCl for 5, 10, 20, 30, 45, 60, 90, 120, 150, 180, and 300 min. Equilibrium time for NH + 4 adsorption ranged from 60 min for 140.1 mg L −1 initial NH + 4 ‐N concentration at pH 4 to 120 min for 840.6 mg L −1 initial NH + 4 ‐N concentration at pH 7. Desorption was nearly complete in 150 min for low initial NH + 4 concentrations and 200 min for high initial NH + 4 concentrations. Amounts of NH + 4 sorbed increased with increasing pH and initial NH + 4 concentrations. Models evaluated included the first‐order kinetics, modified Freundlich, parabolic diffusion, Elovich, and heterogeneous diffusion. All the models adequately described the NH + 4 adsorption process, with r 2 values ranging from 0.955 to 0.999. With the exception of first‐order kinetics, they also described the desorption process well, with r 2 values ranging from 0.897 to 0.999, for all pH and initial NH + 4 concentrations. Reaction rate coefficients ( k ) were calculated from the modified Freundlich model and ranged from 0.134 to 0.193 min −1 for the adsorption process, and 0.129 to 0.226 min −1 for the desorption process. The models indicated that NH + 4 adsorption and desorption by the zeolite was diffusion controlled. Data from this study indicated the potential use of the tested natural zeolite as an NH + 4 adsorbent and a controlled‐release NH + 4 fertilizer.
Membrane technology for the processing of fruit juices and beverages has been applied mainly for clarification using ultrafiltration and microfiltration, and for concentration using reverse osmosis. The effects of product preparation, membrane selection, and operating parameters are important factors influencing filtration rate and product quality. Technological advances related to the development of new membranes, improvement in process engineering, and better understanding of fruit beverage constituents have expanded the range of membrane separation processes. Developments in novel membrane processes, including electrodialysis and pervaporation, increased the array of applications in combination with other technologies for alternate uses in fruit juices and beverages.
Membrane technology for the processing of fruit juices and beverages has been applied mainly for clarification using ultrafiltration and microfiltration, and for concentration using reverse osmosis. The effects of product preparation, membrane selection, and operating parameters are important factors influencing filtration rate and product quality. Technological advances related to the development of new membranes, improvement in process engineering, and better understanding of fruit beverage constituents have expanded the range of membrane separation processes. Developments in novel membrane processes, including electrodialysis and pervaporation, increased the array of applications in combination with other technologies for alternate uses in fruit juices and beverages.
Olfaction plays an important role in the life history of insects, including key behaviours such as host selection, oviposition and mate recognition. Odour perception by insects is primarily mediated by the large diverse family of odourant receptors (Ors) that are expressed on the dendrites of olfactory neurones housed within chemosensilla. However, few Or sequences have been identified from the Lepidoptera, an insect order that includes some of the most important pest species worldwide. We have identified 41 Or gene sequences from the silkworm (Bombyx mori) genome, more than double the number of published Or sequences from the Lepidoptera. Many silkworm Ors appear to be orthologs of the 17 published tobacco budworm (Heliothis virescens) Ors indicating that many Or lineages may be conserved within the Lepidoptera. The majority of the Or genes are expressed in adult female and male antennae (determined by quantitative real-time PCR analysis), supporting their probable roles in adult olfaction. Several Or genes are expressed at high levels in both male and female antennae, suggesting they mediate the perception of common host or conspecific volatiles important to both sexes. BmOrs 45-47 group together in the same phylogenetic branch and all three are expressed at moderate female-biased ratios, six to eight times higher in female compared to male moth antennae. Interestingly, BmOrs19 and 30 appear to be expressed predominantly in female antennae, opposite to that of the published silkworm pheromone receptors BmOrs 1 and 3 that are specific to male antennae. These results suggest that BmOr19 and 30 may detect odours critical to female behaviour, such as oviposition cues or male-produced courtship pheromones.
Ustilago hordei is a biotrophic parasite of barley (Hordeum vulgare). After seedling infection, the fungus persists in the plant until head emergence when fungal spores develop and are released from sori formed at kernel positions. The 26.1-Mb U. hordei genome contains 7113 protein encoding genes with high synteny to the smaller genomes of the related, maize-infecting smut fungi Ustilago maydis and Sporisorium reilianum but has a larger repeat content that affected genome evolution at important loci, including mating-type and effector loci. The U. hordei genome encodes components involved in RNA interference and heterochromatin formation, normally involved in genome defense, that are lacking in the U. maydis genome due to clean excision events. These excision events were possibly a result of former presence of repetitive DNA and of an efficient homologous recombination system in U. maydis. We found evidence of repeat-induced point mutations in the genome of U. hordei, indicating that smut fungi use different strategies to counteract the deleterious effects of repetitive DNA. The complement of U. hordei effector genes is comparable to the other two smuts but reveals differences in family expansion and clustering. The availability of the genome sequence will facilitate the identification of genes responsible for virulence and evolution of smut fungi on their respective hosts.
Simple and polymeric anthocyanins of Pinot noir wines produced by different vinification processes were monitored by high-performance liquid chromatography (HPLC) from the onset of fermentation to bottling. Color characteristics were determined by tristimulus measurement using a spectrophotometer with a color determination and match program. Up to 12 individual polymeric anthocyanins were found. Extraction of monomeric anthocyanins was increased with higher fermentation temperature, but anthocyanin concentration declined gradually after fermentation. In all wines, the dominant type of anthocyanin was malvidin 3-glucoside. In contrast, the content of polymeric anthocyanins increased during fermentation and thereafter, and reached the highest concentrations at bottling. Fermentation temperature was a critical factor for formation of polymeric anthocyanins. The presence of total or individual polymeric anthocyanins was directly related to wine color intensity, and all the polymeric anthocyanins were important to wine color. Keywords: Wine color; polymeric anthocyanins; monomeric anthocyanins; flavonoids; fermentation temperature; HPLC analysis; tristimulus analysis
Abstract Ammonia emissions during composting of poultry manure can be significant, representing increased environmental pollution and decreased fertilizer value of manure. The objectives of this study were to measure NH 3 volatilization losses during composting of poultry layer manure, and to evaluate the potential of different amendments to reduce NH 3 losses using a laboratory composting simulator. The poultry manure was treated with various amendments which included two natural zeolites, clay, coir (mesocarp of coconut fruit), CaCl 2 , CaSO 4 , MgCl 2 , MgSO 4 , and Al 2 (SO 4 ) 3 . The manure was composted for 49 to 56 d. Ammonia volatilized from the manure was trapped in a 0.3 M H 2 SO 4 solution. The composts were weighed and analyzed for moisture content, total N and NH + 4 . The NH 3 volatilization loss for the unamended manures ranged from 47 to 62% of the total manure N. A layer of 38% zeolite placed on the surface of the manure reduced NH 3 losses by 44%, whereas 33% coir placed on the surface of the manure reduced NH 3 losses by 49%. The 20% alum treatment reduced NH 3 losses by 28%. Composting poultry manure with zeolites, coir, and alum produced composts with high NH + 4 concentrations ranging from 17 to 53% of total N. The addition of 20% CaCl 2 to poultry manure decreased NH 3 volatilization but did not result in increased NH + 4 or NO − 3 concentrations. The 38% zeolite Z1 and 33% coir‐treated composts had total N concentrations of 17 and 31 g kg −1 , respectively. The zeolite and coir amendments were proposed to be the most suitable for reducing NH 3 losses during composting of poultry manure.
Abstract Three members of the Puccinia genus, Pucciniatriticina (Pt), P. striiformis f.sp. tritici (Pst), and P. graminis f.sp. tritici (Pgt), cause the most common and often most significant foliar diseases of wheat. While similar in biology and life cycle, each species is uniquely adapted and specialized. The genomes of Pt and Pst were sequenced and compared to that of Pgt to identify common and distinguishing gene content, to determine gene variation among wheat rust pathogens, other rust fungi, and basidiomycetes, and to identify genes of significance for infection. Pt had the largest genome of the three, estimated at 135 Mb with expansion due to mobile elements and repeats encompassing 50.9% of contig bases; in comparison, repeats occupy 31.5% for Pst and 36.5% for Pgt. We find all three genomes are highly heterozygous, with Pst [5.97 single nucleotide polymorphisms (SNPs)/kb] nearly twice the level detected in Pt (2.57 SNPs/kb) and that previously reported for Pgt. Of 1358 predicted effectors in Pt, 784 were found expressed across diverse life cycle stages including the sexual stage. Comparison to related fungi highlighted the expansion of gene families involved in transcriptional regulation and nucleotide binding, protein modification, and carbohydrate degradation enzymes. Two allelic homeodomain pairs, HD1 and HD2, were identified in each dikaryotic Puccinia species along with three pheromone receptor (STE3) mating-type genes, two of which are likely representing allelic specificities. The HD proteins were active in a heterologous Ustilago maydis mating assay and host-induced gene silencing (HIGS) of the HD and STE3 alleles reduced wheat host infection.
Anthocyanins are the largest group of water-soluble pigments in the plant kingdom. They are responsible for most of the red, blue, and purple colors of fruits, vegetables, flowers, and other plant tissues or products. The analysis of anthocyanins is complex as a result of their ability to undergo structural transformations and complexation reactions. In addition, they are difficult to measure independently of other flavonoids, as they have similar structural and reactivity characteristics. Anthocyanins are generally extracted with weakly acidified alcohol-based solvents, followed by concentration (under vacuum), and purification of the pigments. Paper and/or thin-layer chromatography and UV-Vis spectroscopy have traditionally been used for the identification of anthocyanins. Capillary zone electrophoresis, a hybrid of chromatography and electrophoresis, is gaining popularity for the analysis of anthocyanins; however, liquid chromatography (LC) has become the standard method for identification and separation in most laboratories and may be used for both preparative and quantitative analysis. LC with mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy are possibly the most powerful methods for the structural elucidation of anthocyanins available, to date. At present, the most satisfactory method for mixture analysis is the multistep method of separation, isolation, and quantification by LC with peak identification by MS and high-field NMR.
Significance The “centromere paradox” refers to rapidly evolving and highly diverse centromere DNA sequences even in closely related eukaryotes. However, factors contributing to this rapid divergence are largely unknown. Here, we identified large regional, LTR retrotransposon-rich centromeres in a group of human fungal pathogens belonging to the Cryptococcus species complex. We provide evidence that loss-of-functional RNAi machinery and possibly cytosine DNA methylation trigger instability of the genome by activation of centromeric retrotransposons presumably suppressed by RNAi. We propose that RNAi, together with cytosine DNA methylation, serves as a critical determinant that maintains repetitive transposon-rich centromere structures. This study explores the direct link between RNAi and centromere structure evolution.
In an effort to protect field corn ( Zea mays L.) from wireworm ( Agriotes obscurus L.) herbivory and yield loss, seeds were treated with conidia of Metarhizium anisopliae strain F52 alone or in combination with clothianidin or spinosad before planting at three farm fields in south coastal British Columbia, Canada. Corn seed treated with M. anisopliae conidia (main effect) resulted in significant increases in stand density (78% M. anisopliae treated vs. 67% no M. anisopliae ) and stock and foliage area fresh wt. yield (9.6 Mg ha −1 M. anisopliae treated vs. 7.6 Mg ha −1 no M. anisopliae ), and significantly increased plant (stock and foliage) fresh wt. when it was applied together with spinosad or with no additional agrichemical at one location. Spinosad had no effect on corn yield, whereas clothianidin caused a significant increase in plant stand density and yield. Wireworm cadavers showing M. anisopliae strain F52 growth were retrieved from treated plots, suggesting that the increase in yield may have been due to wireworm control. Laboratory experiments provided no evidence that the increase in stand density and yield from the M. anisopliae ‐treated corn seed was attributable to an increase in germination rate or root growth. We concluded that seed treatment with this fungus may be a novel method to increase stand density and yield of corn.