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Diversifying agriculture by rotating a greater number of crop species in sequence is a promising practice to reduce negative impacts of crop production on the environment and maintain yields. However, it is unclear to what extent cereal yields change with crop rotation diversity and external nitrogen fertilization level over time, and which functional groups of crops provide the most yield benefit. Here, using grain yield data of small grain cereals and maize from 32 long-term (10–63 years) experiments across Europe and North America, we show that crop rotational diversity, measured as crop species diversity and functional richness, enhanced grain yields. This yield benefit increased over time. Only the yields of winter-sown small grain cereals showed a decline at the highest level of species diversity. Diversification was beneficial to all cereals with a low external nitrogen input, particularly maize, enabling a lower dependence on nitrogen fertilisers and ultimately reducing greenhouse gas emissions and nitrogen pollution. The results suggest that increasing crop functional richness rather than species diversity can be a strategy for supporting grain yields across many environments.

Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate.

Novel species of fungi described in this study include those from various countries as follows: Australia, Aschersonia mackerrasiae on whitefly, Cladosporium corticola on bark of Melaleuca quinquenervia, Penicillium nudgee from soil under Melaleuca quinquenervia, Pseudocercospora blackwoodiae on leaf spot of Persoonia falcata, and Pseudocercospora dalyelliae on leaf spot of Senna alata. Bolivia, Aspicilia lutzoniana on fully submersed siliceous schist in high-mountain streams, and Niesslia parviseta on the lower part and apothecial discs of Erioderma barbellatum onatwig. Brazil, Cyathus bonsai on decaying wood, Geastrum albofibrosum from moist soil with leaf litter, Laetiporus pratigiensis on a trunk of a living unknown hardwood tree species, and Scytalidium synnematicum on dead twigs of unidentified plant. Bulgaria, Amanita abscondita on sandy soil in a plantation of Quercus suber. Canada, Penicillium acericola on dead bark of Acer saccharum, and Penicillium corticola on dead bark of Acer saccharum. China, Colletotrichum qingyuanense on fruit lesion of Capsicum annuum. Denmark, Helminthosphaeria leptospora on corticioid Neohypochnicium cremicolor. Ecuador (Galapagos), Phaeosphaeria scalesiae on Scalesia sp. Finland, Inocybe jacobssonii on calcareouss oils in dry forests and park habitats. France, Cortinarius rufomyrrheus on sandy soil under Pinus pinaster, and Periconia neominutissima on leaves of Poaceae. India, Coprinopsis fragilis on decaying bark of logs, Filoboletus keralensis on unidentified woody substrate, Penicillium sankaranii from soil, Physisporinus tamilnaduensis on the trunk of Azadirachta indica, and Poronia nagaraholensis on elephant dung. Iran, Neosetophoma fic on infected leaves of Ficus elastica. Israel, Cnidariophoma eilatica (incl. Cnidariophoma gen. nov.) from Stylophora pistillata. Italy, Lyophyllum obscurum on acidic soil. Namibia, Aureobasidium faidherbiae on dead leaf of Faidherbia albida, and Aureobasidium welwitschiae on dead leaves of W

The free amino acid asparagine is the main precursor to formation of acrylamide, a probable carcinogen, in bakery products. Therefore, it is critical to understand if reducing free asparagine in wheat will be detrimental to dough viscoelasticity, and consequently, to the quality of the bread made from the dough. Thus, this study aimed to investigate how factors affecting free asparagine levels in wheat, i.e., environment, genotype, and fertilization treatments, affected dough rheological properties. Because good gluten strength is necessary for good bread quality, this study sought to understand the relationship between wheat free asparagine concentration and gluten strength. Eight commercial Canadian wheat varieties were grown at four site-years under four fertilization treatments, i.e., combinations of two levels of nitrogen and two levels of sulfur. Wheat grain samples were milled into whole-wheat and straight grade flour. Free asparagine concentration was quantified using whole-wheat flours and dough rheological properties were measured using straight grade flours. Empirical dough rheological properties were evaluated using the Brabender Farinograph and the Brabender Extensograph. Using a subset of 10 selected samples, shear rheometry and low-intensity ultrasound (LIU) tests were performed on yeasted and non-yeasted doughs. From empirical tests, it was observed that environment, genotype and their interaction were the main factors affecting gluten strength, with little effect from fertilization. Additionally, gluten strength parameters were negatively correlated to wheat free asparagine concentration. When evaluated under linear shear oscillatory tests, non-yeasted dough rheology significantly changed over time, while prominent dough softening was observed during fermentation of yeasted doughs. When tested under creep-recovery and stress relaxation, a strong negative correlation was observed between wheat free asparagine concentration and gluten strength. Finall

The Assiniboine Delta Aquifer (ADA) is the largest unconfined aquifer and the main water supply for agricultural production in Manitoba, Canada. Groundwater has a critical role in irrigated agriculture to ensure food security, and aquifer recharge is a key to groundwater management. While aquifers are primarily recharged from rainfall and surface sources, return flow from irrigation water can recharge during cropping seasons. The previous studies on the ADA used the water budget method to estimate the recharge but not return flow through irrigation. In this study, both the groundwater recharge and return flow through irrigation water to the ADA were estimated numerically by using HYDRUS-1D. The data were retrieved from soil sensors and weather stations installed at each selected site. This study used three stations on cropland, and three on pastureland. The soil properties used to construct the numerical models were determined by laboratory experiments and retrieved from the Canada-Manitoba Crop Diversification Centre (CMCDC). The numerical models were calibrated by altering the van Genuchten-Mualem (VGM) parameters to match the observed and estimated soil water content. This modelling step was carried out by coupling HYDRUS-1D with Pareto Archived Dynamically Dimensioned Search (PA-DDS) using MATLAB. The results of this research showed that the estimated groundwater recharge based on simulations for the 2019 and 2020 cropping seasons was significantly higher than reported in previous studies and that the return flow on the irrigated cropland positively impacted the groundwater recharge. Return flow was higher in 2019 which was considered a normal year and reduces strongly in the dry year of 2020. The outcomes would be beneficial for new water licensing, an increase in agricultural production, and more importantly, sustainable groundwater management of the Assiniboine Delta Aquifer by limiting the environmental impact from the irrigation withdrawals .

[EN] This study aimed to characterise the quality of meat from commercially-raised rabbits. Animals came from five different producers and were laughtered in three different plants under provincial or federal inspection jurisdiction. Animal behaviour evaluated by scan sampling prior to feed withdrawal (FW) and transport, as well as blood lactate concentration at exsanguination, did not raise concerns with respect to stress. Stomach pH was higher (P=0.047) when the FW time was short (≤13.5 h), at a mean value of 2.23. All pH values measured 1 h post-mortem from the Biceps femoris (BF) and almost all (97.6%) from the Longissimus lumborum (LL) were higher than 6. Values for ultimate pH measured 24 h postmortem(pHu) ranged from 5.80 to 6.83 and from 5.70 to 6.70 for BF and LL muscles, respectively. The maximum meat drip loss recorded was 2.6%, while cooking loss reached 30%. Meat lightness (L*) and colour intensity (C*) for the long FW times (≥23 h) were no different from those with short and intermediate (15.5 to 17.3 h) FW times. However, these colour parameters were higher for the short FW time class compared to the intermediate FW time class (P<0.02). A hierarchical cluster analysis based on pHu, cooking loss and lightness (L*) from 200 rabbit loins was performed. Of the four clusters created, clusters 1 and 2 had the best and second-best meat quality, respectively. Clusters 3 and 4 had the lowest meat quality and presented DFD-like (dark, firm and dry) characteristics. Meat did not exhibit PSE-like (pale, soft, exudative) characteristics, even for the slaughter lot with the minimum mean pHu. Of the eight slaughter lots evaluated, more than 50% of the meat from three of them fell into clusters 3 and 4; all three were in the intermediate FW time class. Overall, the quality of rabbit meat analysed was acceptable for commercial use, but rather variable. This suggests that there are factors within the value chain that are not yet fully controlled and require further

Late blight is one of the most devastating diseases on potato and tomato, which are important crops worldwide. The disease is caused by an oomycete, a fungus- like organism, Phytophthora infestans. The disease can result in a loss of an entire yield within a few days if left unchecked. Historically, late blight caused the famous Irish famine in the 1840s and continues to affect potato and tomato. The most recent pandemics of late blight that occurred in North America were caused by new P. infestans genotypes known as US-22, US-23 and US-24, and resulted in significant yield losses of both potato and tomato. In this study, isolates from infected potato and tomato plants collected in Canadian provinces during 2012 were identified, and some of the work was performed in collaboration with other scientists across Canada. Our results concluded a great shift of P. infestans populations within a single year, from US-24 and US-8 in 2011 to US-23 in 2012. Isolates of some populations showed increased insensitivity to mefenoxam as well as recombination. We confirmed an independent segregation of either Gpi, mating type or RG57 loci in a number of the recombinant isolates including CA12. Cross-pathogenicity of different isolates belonging to different genotypes were evaluated on susceptible and moderately resistant cultivars of potato and tomato. Isolates of genotypes US-8, US-11, US-22, US-23 and US-24 were assessed for their pathogenicity on both tomato and potato leaves as well as on tubers, at different days post inoculation (dpi). This allowed us to investigate their pathogenicity on both the original and alternative hosts of each tested isolate. Area under disease progress curve (AUDPC) was measured at 3, 5, and 7 dpi on plant leaves. We revealed higher infection caused by most US-24 isolates in all tested cultivars. Observation of more blight in Russet Burbank, the susceptible potato cultivar was recorded, followed by Sun Rise and Ultra Sweet, the susceptible and the mod

Wheat leaf rust, caused by Puccinia triticina Eriks. (= P. recondita Rob. Ex Desmaz. f. sp. tritici), is the most widespread disease of wheat worldwide and causes average annual yield losses of 5 to 25%. The emergence of a new predominant race of leaf rust, TDBG, in the 2004 Canadian virulence survey led to the identification of a second leaf rust resistance gene segregating in the Thatcher-Lr1 near-isogenic differential line, RL6003, which produced an unusual mesothetic infection type. This gene was subsequently isolated in a Thatcher background and temporarily designated as LrCen (Tc-LrCen). A cross was made with a susceptible parent (Tc-LrCen/ Sumai3-lr34) and a doubled haploid (DH) mapping population was generated from the hybrids. Parental lines and 180 double haploid (DH) individuals were phenotyped with race TDBG and a 1:1 ratio was observed in the DH population. Parental lines and 94 DH individuals were genotyped with the Illumina Infinium assay using a custom iSelect 90K wheat SNP array. Two-point linkage between the phenotype and polymorphic SNP markers identified linked markers. A BLAST search of linked SNP sequences was performed against the Wheat Survey Sequence providing a putative chromosomal location of 7AL. Subsequent mapping with microsatellite markers confirmed LrCen was located on the long arm of chromosome 7A flanked by gwm344 (9.5 cM) and cfa2240 (0.6 cM) as well as a group of co-segregating SNPs also at a genetic distance of 0.6 cM. When the SNP sequences were converted to the kompetitive allele specific PCR (KASP) markers they were found to be dominant, making them less useful for marker assisted selection in populations with heterozygotes. LrCen mapped distal to Lr20; the only other Lr gene previously identified on chromosome 7AL.

Antimicrobials are widely used in North America’s livestock industry. Field application of livestock manure disperses antimicrobials in to the environment. Antimicrobials can increase the level of antimicrobial resistance development in human and livestock pathogens. Three main studies were conducted to: i) quantify the simulated rain runoff losses of chlortetracycline, sulfamethazine and tylosin following surface application vs. soil incorporation of beef cattle feedlot manure; ii) quantify the dissipation kinetics of these antimicrobials in a seasonally-frozen soil following field application of manure; and iii) quantify and compare the dissipation of excreted vs. fortified (that is, added to antimicrobial-free manure) antimicrobials during indoor composting. Manure was sourced from cattle (Bos taurus) receiving no antimicrobial (control), 44 mg chlortetracycline, 44 mg each of chlortetracycline and sulfamethazine, or 11 mg tylosin per kg-1 feed. Antimicrobial concentration in simulated rain runoff following field application of manure generally reflected the corresponding concentrations in manure. Mass loss ranged from 1.7 to 6.5% for chlortetracycline and was 4.8% for sulfamethazine and 0.24% for tylosin. Incorporation of manure into the top 10 cm of soil significantly reduced the mass loss of chlortetracycline and the concentration in runoff of both chlortetracycline and sulfamethazine. Both chlortetracycline and sulfamethazine were persistent in the seasonally-frozen Canadian prairie soil tested. The first-order dissipation half-life (DT50) for chlortetracycline added along with sulfamethazine was 77 d during the growing season and 648 d during the non-growing season. The DT50 of chlortetracycline added alone did not differ significantly between the two seasons (mean DT50 = 121 d). Sulfamethazine was detected throughout the 10-mo monitoring period (mean ≤ 16 ± 10 µg kg-1). Composting dissipated 85–99% of initial concentrations of chlortetracycline, sulfamethaz

The fungal pathogen, Fusarium graminearum, is a primary causal agent of the wheat (Triticum aestivum L.) disease Fusarium head blight in North America. Heavy infection from this pathogen leads to economic losses due to a decrease in the quality and quantity of grain. Infection by F. graminearum also leads to accumulation of deoxynivalenol (DON), a mycotoxin that produces harmful side effects to both humans and animals when ingested. Development of resistant wheat cultivars is needed to maintain a sustainable, safe, food supply. In this study, a double haploid population derived from a cross between two winter wheat cultivars, Flourish and Emerson, was used to identify quantitative trait loci (QTL) associated with FHB symptoms and DON accumulation in the grain. So far, there are no fully resistant cultivars of wheat to protect against FHB infection. Therefore, alternative methods need to be considered. A newly developed bio-fungicide containing a fungal antagonist to F. graminearum, Clonostachys rosea, was studied and compared to the commercially available fungicide, Caramba® (active ingredient, metconazole). These QTL were present on chromosomes 1B, 2B, 4D, 6D and 7A. Results from this study showed that there was some potential in using C. rosea in a bio-fungicide treatment plan. However, the fungi’s sensitivity to environmental conditions may have contributed to poor and inconsistent control of F. graminearum in this study.

Feed costs have led the cattle industry to examine the merit of selecting cattle for inputs (feed efficiency) rather than for outputs exclusively (growth). Residual feed intake (RFI) has become a preferred measure of biological efficiency. Feeding behaviour traits (feeding event duration, frequency, head-down time, length and eating rate) and temperament may provide insight into the variation in feed efficiency. Feeding behaviour, RFI (n = 868) and temperament (n = 58) were examined using five classes of beef cattle. Cattle were sorted into low, medium and high RFI groups. Feeding behaviour traits were moderately (-0.21 to 0.56; P < 0.05) related to RFI. Bulls fed a grain-based diet spent longer periods lying down than bulls fed a forage-based diet. No relationships (P > 0.1) were observed between RFI and bull temperament, indicating that temperament is not correlated with RFI and selecting for low RFI cattle will not negatively impact temperament.

An annotated reference sequence representing the hexaploid bread wheat genome in 21 pseudomolecules has been analyzed to identify the distribution and genomic context of coding and noncoding elements across the A, B, and D subgenomes. With an estimated coverage of 94% of the genome and containing 107,891 high-confidence gene models, this assembly enabled the discovery of tissue- and developmental stage–related coexpression networks by providing a transcriptome atlas representing major stages of wheat development. Dynamics of complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. This community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding.

Blackleg, caused by the fungal pathogen Leptosphaeria maculans (Desm.) Ces. & De Not, is an economically important disease in canola (Brassica napus L.) production. This study explored how temperature affects the Rlm gene- mediated resistance to L. maculans in canola. It also investigated the frequency of AvrLm genes and race structure of L. maculans in High Erucic Acid Rapeseed (HEAR) and canola fields in Manitoba, Canada. This study found that Rlm1, Rlm2, Rlm3 and Rlm4 in Topas isogenic lines (ILs) of B. napus are not sensitive to temperature, while Rlm3 in Quantum and Rlm4 in Falcon broke down at higher temperatures of 25/20 and 30/25 °C. The temperature had a significant effect on lesion size, where a higher temperature resulted in larger lesions in Topas ILs. Temperature also had a significant effect on L. maculans, where the optimum temperature was 25 °C for its growth and sporulation. Under different temperature treatments, different genotypes with the same Rlm genes responded differently to L. maculans. This may indicate that the genetic background is important in single Rlm gene-mediated resistance expression. This study also identified and examined 297 isolates of L. maculans from stubble collected in HEAR and canola fields in Manitoba in the 2013 and 2014 growing season. AvrLm6 and AvrLm5 were present in more than 90% of the population; AvrLm7, AvrLm4, AvrLm11, and AvrLm2 were present in more than 50% of isolates, while AvrLm3 and AvrLm9 had a very low frequency. In total, 85 races were identified, and AvrLm2-4-5-6-7-11 was identified in 14.8% of the population. AvrLm9 was not found in Manitoba in the 2014 growing season. The frequency of AvrLm genes and race structures varied over years, regions and cultivars.

Agricultural soils in the Prairies encompasses 80% of Canada’s farmland that may contain a range of chemical compounds, including phosphate and cadmium from fertilizer application, glyphosate and MCPA from herbicide application and/or the antibiotic tetracycline following livestock manure application. The aim of this PhD research was to examine the competitive sorption effects of these inorganic and organic chemicals in soil. Soil samples were collected in 2013 from two research sites that had received repeated annual application (2002-2009) of mono ammonium phosphate at 20, 40 and 80 kg P ha-1 with cadmium added at low, medium or high rates. A series of batch equilibrium experiments were conducted to quantify sorption of phosphate, glyphosate, MCPA and tetracycline. Results showed that cadmium concentrations in soil had no significant effect on sorption of glyphosate. Sorption of glyphosate significantly decreased with increasing phosphate concentrations in soils regardless of whether phosphate levels arose from repeated applications in the field, or from fresh applications in the laboratory. Similarly, sorption of phosphate significantly decreased with increasing phosphate concentrations in soils, suggesting that the capacity of soils to retain phosphate or glyphosate was reduced resulting from previous (repeated) phosphate fertilizer applications. The effect of phosphate on reducing phosphate and glyphosate sorption was greater in an acidic soil that had high Fe/Al-oxides than in slightly alkaline calcareous soil. Analytical-grade glyphosate and commercially-available glyphosate formulation, Roundup Ultra2, behaved similarly for their sorption pattern. Phosphate sorption was not significantly impacted when Roundup Ultra2 was added to soil slurries in the laboratory. Repeated application of phosphate in the field had no significant impact on MCPA and tetracycline sorption, but fresh addition of phosphate in the laboratory significantly reduced MCPA and tetracyclin

Landscape complexity and arthropod predators have been shown to play a major role in suppression of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae) in North America. I examined the impact of landscape complexity and patterns of predator movement between habitats on sentinel soybean aphid populations in 27 soybean fields in Manitoba over a two-year period. Predator movement was quantified using bi-directional Malaise traps and mark-release-recapture experiments. My results revealed that there was a strong to moderate suppression of soybean aphids across the gradient of landscape complexity studied. I found that predator movement between soybean and adjacent habitats was as important as landscape characteristics in explaining aphid suppression. My results indicate that the direction of predator movement in soybean field borders is influenced by the type of adjacent habitat and by predator identity. My findings highlight the importance of pest control services provided by aphidophagous predators in agricultural landscapes.

Little is known about fatty acid (FA) distribution among triacylglyceride (TG), cholesterol ester (CE), and phospholipid (PL) plasma lipid fractions in lactating women, and the relationships between these fractions and the FA profile of the milk that mothers produce. Milk fat and serum lipid FA compositions in lactating women were compared to investigate which serum lipids are the source of FA in milk fat. A TLC methodology was used to fractionate serum lipids including PL subclasses, that is, phosphatidylethanolamine (PE), phosphatidylcholine (PC), and sphingomyelin (SM). Plasma lipids consisted of CE (36.4%), TG (19.1%), PE (1.40%), PC (39.80%), and SM (3.29%). With regard to PL fractions, PE was characterized by the highest levels of 18:0, 20:4 n‐6, 22:6 n‐3, and alkenyl ethers. PC revealed 16:0 as the predominant FA, followed by 18:2 n‐6, 18:0, cis‐9 18:1, and 20:4 n‐6, whereas saturated FA from 16:0 to 24:0 were characteristic of SM. Although n‐6 and n‐3 polyunsaturated FA were mostly found in PE and PC, strong correlations were found for 18:2 n‐6 and 18:3 n‐3 between plasma TG and milk lipids. This study also shows that trans 18:1 isomers may be selectively incorporated into milk fat from specific serum fractions.

[Background] The diet of breastfeeding women influences the trans fatty acid (TFA) composition of the milk excreted. However, the effects associated to TFA are isomer-dependent and diverse TFA profiles may have different nutritional implications., [Objective] The aim of this research was to evaluate whether certain TFA patterns in human milk fat can be used as indicators of TFA intake from different sources., [Methods] Milk fat from 60 women were examined and classified based on their TFA profile and conjugated linoleic acid (CLA) contents by principal component analysis (PCA)., [Results] The PCA of the data allowed the classification of the women into 3 groups depending on milk TFA content and profile. From the 60 subjects, 19 presented a TFA profile characteristic of ruminant products intake, 10 a typical TFA profile of industrial trans fats consumption and 31 a negligible trans content. Superimposed on this, 21 women presented high amounts of docosahexaenoic acid (22:6 n-3) which was related to fish intake., [Conclusions] The present research overcome problems associated to heterogeneous groups in nutritional experiments by a statistical classification of lactating subjects based on the TFA composition of their milk. This classification could be extrapolated to other nutritional studies dealing with TFA analysis and samples of different nature as biological samples or foodstuffs.

During an insect sampling program in alfalfa crops near Montpellier, France in 2011, Lacanobia oleracea larvae were collected that died due to nucleopolyhedrovirus infection (LaolNPV). This virus was subjected to molecular and biological characterization. The virus was a multiple nucleocapsid NPV that showed similar restriction profiles to Mamestra configurata NPV-A (MacoNPV-A) but with significant differences. Polypeptide analysis demonstrated similar proteins in occlusion bodies and occlusion derived virions, to those observed in NPVs from Mamestra spp. Terminal sequencing revealed that the genome organization shared similarity with that of MacoNPV-A. The most homologous virus was MacoNPV-A 90/2 isolate (95.63% identity and 96.47% similarity), followed by MacoNPV-A 90/4 strain (95.37% and 96.26%), MacoNPV-B (89.21% and 93.53%) and M. brassicae MNPV (89.42% and 93.74%). Phylogenetic analysis performed with lef-8, lef-9, polh and a concatenated set of genes showed that LaolNPV and the Mamestra spp. NPVs clustered together with HaMNPV, but with a closer genetic distance to MacoNPV-A strains. The Kimura 2-parameter (K-2-P) distances of the complete genes were greater than 0.05 between LaolNPV and the MbMNPV/MacoNPV-B/HaMNPV complex, which indicates that LaolNPV is a distinct species. K-2-P distances were in the range 0.015–0.050 for comparisons of LaolNPV with MacoNPV-A strains, such that additional biological characteristics should be evaluated to determine species status. While MacoNPV-A was pathogenic to seven lepidopteran species tested, LaolNPV was only pathogenic to Chrysodeixis chalcites. Given these findings, Lacanobia oleracea nucleopolyhedrovirus should be considered as a new species in the Alphabaculovirus genus.

Potato cyst nematodes (PCNs), Globodera rostochiensis and G. pallida, cause important economic losses. They are hard to manage because of their ability to remain dormant in soil for many years. Although general knowledge about these plant parasitic nematodes has considerably increased over the past decades, very little is known about molecular events involved in cyst dormancy and hatching, two key steps of their development. Here, we have studied the progression of PCN transcriptomes from dry cysts to hatched juveniles using RNA-Seq. We found that several cell detoxification-related genes were highly active in the dry cysts. Many genes linked to an increase of calcium and water uptake were up-regulated during transition from dormancy to hydration. Exposure of hydrated cysts to host plant root exudates resulted in different transcriptional response between species. After 48 h of exposure, G. pallida cysts showed no significant modulation of gene expression while G. rostochiensis had 278 differentially expressed genes. The first G. rostochiensis significantly up-regulated gene was observed after 8 h and was coding for a transmembrane metalloprotease. This enzyme is able to activate/inactivate peptide hormones and could be involved in a cascade of events leading to hatching. Several known effector genes were also up-regulated during hatching.

One strategy to manage pig slurry is centrifugation and composting of the solids fraction to produce a value added product to distribute manure nutrients further from productions sites. This study determined turned windrow composting was suitable for processing slurry solids throughout winter. It was also the first attempt at combining automated chambers and a Fourier Transform Infrared spectroscopy analyzer to measure multiple gases during the composting process; the system proved capable but captured fluxes better if conducted in an area sheltered from wind. Straw and woodshavings were shown suitable as bulking materials for composting slurry solids, however, the lack of porosity provided by woodshavings created anaerobic conditions that doubled the greenhouse gas emissions compared to those of straw, 1,126 kg CO2-equivalent Mg-1 compared to 526 kg CO2-equivalent Mg-1. Either bulking material produced compost of quality for use in agricultural or soil blending applications and was free of manure pathogens.

Application of phosphorus fertilizer can lead to changes in soil test P and increase both labile and non-labile phosphorus pools. Sequential fractionation showed that the labile (H2O-P and NaHCO3-P) fractions significantly (P < 0.05) increased with the addition of phosphorus fertilizer across all sites. Significant increase was observed in the non-labile (NaOH-P, HCl-P and Residual-P) fractions during the accumulation phase. During the depletion phase, when no further P was added, the accumulated P in the labile P fractions declined but not to the original level. The rates of P application, soil properties, soil test P methods used and time effect all had significant effects on soil test P changes in the extraction experiment. Mehlich-3 extracted the greatest amount of P from the two depths and Olsen-P was intermediate while the smallest amount was extracted with water. The pattern of the rate of change in extractable P with P addition for the 0 – 7.5 cm depth was not site dependent as the results obtained at the different sites were similar.

Sediments negatively impact the quality of surface waters and are a significant source of contaminants, such as nutrients and pesticides in agricultural watersheds. Sediment fingerprinting is a relatively recent technique capable of determining the origin of suspended sediment. In this thesis, we investigated the sources of suspended sediments in a predominantly rural watershed in Atlantic Canada. Our first objective was to determine sediment source apportionment estimates by treating the watershed as a single catchment, and making the assumption that conditions affecting source production and transport, from the land to the stream, were uniform across the watershed. For the first objective, suspended sediments were collected at a single target location for sediment apportionment (main outlet) and used to represent sediment dynamics throughout the entire catchment. For the second objective, we examined not only the whole watershed but also sub-watersheds within it, to better understand processes affecting sediment dynamics.

Flooding in the Assiniboine River Basin has increasingly resulted in major crop and infrastructure losses. Since the early 2000’s, flood events have occurred more frequently and with greater impact. As floodwaters travel over agricultural fields, soil particles and nutrients are carried downstream. These particles and nutrients are a major factor in water quality degradation contributing nitrogen and phosphorus to Manitoba’s rivers and lakes. This practicum aims to increase the storage capacity of existing wetlands in a prairie landscape so that a 100-year storm event can be managed on-site. A site in Broughton’s Creek Watershed was. It was determined that the quantity of runoff could be significantly reduced and the quality of water would increase. This approach could be applied to other locations within the Assiniboine River Basin to create a landscape resilient to flood events and downstream water quality degradation.

Blackleg disease, caused by the ascomycete fungal pathogen Leptosphaeria maculans, is a devastating disease of canola (Brassica napus) in Australia, Canada and Europe. The pathogen is considered a global invasive species and poses a threat to canola production in China, where only the weakly aggressive strain L. biglobosa is present. In Canada, breakdown of blackleg resistance has been shown. In order to develop a more effective disease management strategy, there is a need to elucidate host resistance and defense mechanisms underlying the B. napus-L. maculans pathosystem. This is the very first study to investigate major resistance genes (R genes) and adult plant resistance (APR) in Canadian canola germplasm. This study also analyzed the avirulence allele frequency in L. maculans populations in western Canada. R genes were detected in the majority of these B. napus germplasm, with the Rlm3 gene being predominant. The frequency of AvrLm3 allele in field fungal populations was extremely low. APR was identified in more than 50% of the germplasm. This indicated the breakdown of Rlm3 resistance, which could be due to the widespread use of this single resistance gene in Canadian B. napus germplasm and varieties. To address concerns of introducing L. maculans from Canada into China, this study further characterized R genes and APR to L. maculans in a collection of Chinese B. napus germplasm. R genes were detected in more than 40% of the germplasm tested, with Rlm3 and Rlm4 being predominant. A large portion of the Chinese germplasm showed high to moderate APR in field trials at three locations in MB, SK and AB in western Canada. This study highlighted the availability of fair to good resistance in the Chinese B. napus germplasm against blackleg disease and was the first study to investigate a large number of Chinese germplasm against Canadian fungal populations in different environments. RNA sequencing of resistant and susceptible host tissues and a streamlined bioinformat

The objective of the study was to evaluate utilization of dietary minerals and trace elements in pregnant heifers with distinct residual feed intakes (RFI). Feed intake, body weight (BW), and body composition traits were recorded in 36 crossbred heifers over a period of 37 wk, starting shortly after weaning at 8.3 (0.10; standard deviation) mo of age with an average BW of 276 (7.8) kg. Both BW and body composition were monitored regularly throughout the study, whereas individual feed intake was assessed during the last 84 d of the trial. Data recorded were used to calculate RFI for each heifer. Heifers were ranked based on RFI and assigned to high (n = 14) or low (n = 10) RFI groups. After the RFI study, 24 selected heifers [age 18.2 (0.14) mo; 87.5 (4.74) d in gestation; 497 (8.5) kg of BW] were used in an indirect digestibility trial (lignin as internal marker). Heifers were fed a ration containing corn silage, haylage, and a mineral premix in which Ca, P, K, Na, Mg, S, Cu, Fe, Mn, Mo, Se, Zn, and Co were provided in the diet according to National Research Council requirements of pregnant replacement heifers. The digestibility trial lasted 1 wk, during which samples of feces were gathered twice daily, and blood and liver biopsy samples were collected on the last day. We noted no significant differences between low- and high-RFI heifers in dry matter digestibility. Apparent absorption of Cu, Zn, and Mn was increased in heifers with low RFI, and apparent absorption of Co tended to be greater for these animals. Concentrations of macrominerals and trace elements in serum of pregnant heifers were similar for both groups except for Se, which was increased in the serum of low-RFI heifers. Liver concentrations of Cu, Fe, Mn, Mo, Se, and Zn did not differ between low- and high-RFI heifers. In conclusion, whereas improved absorption of some trace elements (Cu, Zn, Mn, and Co) and increased Se serum concentration appear to be associated with superior feed efficiency in pregn

The physiological benefits of flaxseed against pathological disturbances, such as cancers and heart diseases, are mainly attributed to its high lignan content. This study (Experiment 1) examined the application of pressurized low polarity water (PLPW) for extraction of lignans, proteins and carbohydrates from defatted flaxseed meal. Key processing conditions included temperature (130, 160, 190°C), solvent pH (4, 6.5 and 9), solvent to solid ratio (S/S) (90, 150 and 210 mL/g) and introduction of co-packing material (0 and 3 g glass beads). The addition of 3 g glass beads as co-packing material facilitated extraction by enhancing surface contact between the liquid and solid thus shortening extraction time. Elevated temperature accelerated the extraction rate by increasing the solid diffusion coefficient thereby reducing the extraction time. The maximum yield of lignans (99 %) was obtained at temperatures ranging from 160°C to 190°C, with solvent volume of 180 mL (90 mL/g meal) at pH 9. Optimal conditions for protein extraction (70 %) were pH 9, extraction volume of 420 mL (210 mL/g meal) and 160°C. Total carbohydrates yield was maximized at 50% recovery at pH 4 and 160°C with 420 mL solvent (210 mL/g meal). Increased temperature accelerated extraction, thus reducing solvent volume and time to reach equilibrium. For the extraction of proteins, however, a temperature of 130-160°C is recommended, as proteins are vulnerable to thermal degradation due to heat decomposition. The effects of flow rate and geometric dimensions for extraction of lignans and other flaxseed meal bioactives were further investigated in Experiment 2, based on the variables optimized in the previous experiment. Defatted flaxseed meal was extracted with pH 9 buffered water with meal to co-packing glass beads ratio of 1:1.5 at 5.2 MPa (750 psi) and 180°C. The aqueous extracts were analyzed for lignan, protein and carbohydrate using HPLC and colorimetric methods. The optimal extraction yields for ligna

Organic soil amendments play important roles in the reduction of plant diseases caused by soil-borne plant pathogens. This study examined the combined effects of concentrations of organic amendments, temperature and period of incubation in soil on the management of Fusarium wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici (Fol). In an experiment with substrate mixture, Fol reduction was higher when the soils were incubated at 35°C than at 30°C. Disease severity was proportionally reduced as the volume of amendment added increased. Furthermore, disease was significantly lower in substrates incubated for 30-days at both temperatures, as compared to substrates incubated for only 15-days. The most effective control was achieved with pelletised poultry manure (PPM). In experiments with natural sandy soil, the effects of amendments on Fol populations, measured by real-time quantitative PCR with TaqMan probes, were significant. The highest decreases in Fol DNA resulted when the soil was amended with 2% PPM and incubated at 35°C. The reductions in DNA concentrations was most likely related to the accumulations of high concentrations of NH3 (27.3-mM) in soils treated with 2% PPM and incubated at room temperature (RT; 23-±-2°C), or at 35°C. Severity of plants grown in soils incubated at RT decreased by over 40%, and more than 73% when incubated at 35°C, regardless of the rate of PPM. The results indicate that the management with PPM, when combined with heating or solarisation, is an effective control measure against Fusarium wilt of tomato. © 2014 Association of Applied Biologists.

Fusarium crown and root rot (FCRR) of asparagus has a complex etiology with several soilborne Fusarium spp. as causal agents. Ninetythree Fusarium isolates, obtained from plant and soil samples collected from commercial asparagus fields in southwestern Ontario with a history of FCRR, were identified as Fusarium oxysporum (65.5%), F. proliferatum (18.3%), F. solani (6.4%), F. acuminatum (6.4%), and F. redolens (3.2%) based on morphological or cultural characteristics and polymerase chain reaction (PCR) analysis with species-specific primers. The intersimple- sequence repeat PCR analysis of the field isolates revealed considerable variability among the isolates belonging to different Fusarium spp. In the in vitro pathogenicity screening tests, 50% of the field isolates were pathogenic to asparagus, and 22% of the isolates caused the most severe symptoms on asparagus. The management of FCRR with soil organic amendments of pelleted poultry manure (PPM), olive residue compost, and fish emulsion was evaluated in a greenhouse using three asparagus cultivars of different susceptibility in soils infested with two of the pathogenic isolates (F. oxysporum Fo-1.5 and F. solani Fs-1.12). Lower FCRR symptom severity and higher plant weights were observed for most treatments on 'Jersey Giant' and 'Grande' but not on 'Mary Washington'. On all three cultivars, 1% PPM consistently reduced FCRR severity by 42 to 96% and increased plant weights by 77 to 152% compared with the Fusarium control treatment. Populations of Fusarium and total bacteria were enumerated after 1, 3, 7, and 14 days of soil amendment. In amended soils, the population of Fusarium spp. gradually decreased while the population of total culturable bacteria increased. These results indicate that soil organic amendments, especially PPM, can decrease disease severity and promote plant growth, possibly by decreasing pathogen population and enhancing bacterial activity in the soil. © 2014 The American Phytopathological Soc

Preharvest sprouting (PHS), the germination of seeds on the maternal plant before harvest, is a big challenge for barley producers worldwide. It is attributed mainly to low seed dormancy. The balance between two classical plant hormones, gibberellin (GA) and abscisic acid (ABA) regulates seed dormancy and germination, and the endogenous level of these two hormones in plants is determined by their biosynthesis and catabolism. This thesis characterized the expression patterns of the major GA and ABA metabolism genes in barley cv. Betzes during seed development, and germination in both dormant and non-dormant seeds. The results indicate that specific gene family members of the two hormones play distinct temporal roles in regulating seed development, dormancy onset and release, and germination. Since only two genes encoding the GA deactivating GA 2-oxidase enzyme have been known so far in barley, this study also identified two new GA2ox genes designated as HvGA2ox1 and HvGA2ox3.

Boivin, G., Hance, T. and Brodeur, J. 2012. Aphid parasitoids in biological control. Can. J. Plant Sci. 92: 1Á12. Aphids are important pests of most cultivated crops worldwide. Among the natural enemies that regulate their populations, aphid parasitoids are commonly used in biological control programs in greenhouses and field situations. They belong to the Hymenoptera (Braconidae and Aphelinidae), and a few species are Diptera (Cecidomyiidae). Aphid parasitoids are themselves exposed to a variety of natural enemies including predators, fungi and hyperparasitoids. The most important impediment to the use of aphid parasitoids as biological control agents remains the production cost to mass-rear parasitoids. Rearing either aphids or directly aphid parasitoids in artificial media could be a solution to produce large quantities of aphid parasitoids at low cost, but such an approach still faces numerous challenges related to the nutritional and physiological requirements of developing aphid parasitoids.

A static in vitro digestion method was developed as a strategy to understand the effects of modelled digestion on the solubility of nutrients and selected bioactive compounds of autoclaved and untreated wheat bran. Brans from common soft, hard, and durum wheats were evaluated. Results indicated that the in vitro digestion protocol was suitable and effective. Effects of gastrointestinal simulation were considerably larger than gastric digestion alone. Digestibility of the brans ranged from 28.1 to 47.9%. Digestibility of bran minerals, starch and protein was substantial compared to lesser, but still significant, effects on fibre. Fibre solubility was significantly enhanced due to autoclaving. Total phenolic content, free radical scavenging and metal chelation activity were all substantially increased in soluble digests. Yields of these factors indicated that digestion of wheat bran releases ample levels of antioxidants that would be available for absorption in the small intestine to promote beneficial health effects.

A 2007 survey of muscid flies from Churchill, Manitoba, Canada, yielded 155 species. The diversity of this contemporary assemblage was compared to that of an historical (pre-1965) assemblage. Few differences were found between assemblages for material collected by net sweeping and most non-overlapping species between time periods were rare in samples and/or collected by different methods. DNA barcoding was used as a tool to assist with the identification of Muscidae specimens. Performance of the cytochrome c oxidase subunit 1 gene (COI) in the discrimination of muscid species was assessed and correspondence levels of 98.6% were established between species limits recovered by DNA barcode clusters and morphology. I conclude that the great majority of species limits currently accepted in the literature are adequate for Muscidae and that DNA barcoding is a useful identification tool for this family.

Storage at low temperature is a valuable method for increasing the shelf-life of natural enemies such as insect parasitoids. Cold storage is usually performed under sub-optimal temperatures, and therefore it is generally associated with major fitness costs. Tolerance to cold storage is a very plastic trait influenced by a wide range of endogenous (biotic) and exogenous (abiotic) factors experienced before, during, or after cold exposure. In fact, every hierarchical level from inter-species to inter-individuals shows a high plasticity in the response to cold exposure. Mortality represents the ultimate level of a range of sub-lethal perturbations accumulating during chilling. Even if individuals remain alive after cold storage, a reduction of several fitness-related traits may be observed directly, later in development or even in the next generation. The present review focuses on cold storage of insect parasitoids. We first consider the genotypic-based plasticity in cold storage tolerance and the complex network of endogenous and exogenous factors affecting the phenotypic plasticity in cold storage tolerance. We also summarize and examine the wealth of fitness-related traits affected by cold storage in parasitoids. This review provides a comprehensive list of documented factors that must be taken into account when designing cold storage protocols.

Fusarium head blight (FHB), caused mainly by Fusarium graminearum, is one of the most destructive global diseases of small cereal grains worldwide. The most devastating effect of this disease is the deposition of mycotoxins in the grain. Deoxynivalenol (DON) and its analogs 3-ADON, 15-ADON and NIV are the major mycotoxins produced by the fungus. The chemotype, 15-ADON is more prevalent in North America, but recently a chemotypic shift has been observed. The rapid emergence of the 3-ADON chemotype over the traditional 15-ADON chemotype is a major concern in North America. The studies in this thesis were focused on understanding the behaviour of the 3-ADON and 15-ADON chemotypes and the possible reasons for the rapid chemotypic shift.

A study was conducted to determine if sainfoin, a condensed tannin (CT) containing legume, fed to beef cattle as hay or silage during a western Canadian winter would result in a reduction in methane (CH4) emissions without compromising animal performance. Forty yearling beef steers were fed four diets in a factorial design consisting of two legume forage species (sainfoin or alfalfa) and two preservation methods (silage or hay) over 15 weeks (wks). For each sample wk, animal weight, 24-h CH4 expiration and rumen fluid samples were obtained. Rumen methanogens were characterized using terminal restriction fragment length polymorphisms analysis. Specific bacteria were quantified with real-time polymerase chain reaction analysis. Sainfoin silage (SS) and sainfoin hay (SH) contained 11.9 and 10.5 mg g-1 of CT respectively and supported an acceptable growth rate for backgrounding steers. A decline (P < 0.05) in enteric CH4 formation could only be detected from SH-fed animals compared to alfalfa hay (AH) fed animals when CH4 was expressed as L d-1 or L kg BW-1. The rumen archaeal community structure of experimental animals remained stable regardless of diet type or sample wk. Structural carbohydrate-fermenting bacteria were suppressed in silage diets. Methanogens were less abundant in the rumen fluid samples of steers fed SS but not SH.

The objectives of the study were to evaluate the soil disturbances and manure dispersion created by the AerWay aerator in a silt loam soil; and to generate a calibrated and validated soil-tool model using Discrete Element Methods (DEM) that simulate the draft and vertical forces of the aerator. The experimental results showed that a trend indicated that the faster tractor speeds would disturb more soil. After one hour with the manure application rate of 42 000 L/ha, manure was spread to a depth of 250 mm, 200 mm in the forward direction and 100 mm in the lateral direction. The model draft forces had a relative error of 13.4-31.2% when compared to the literature data between 100-150 mm depth while the predicted vertical force was found to linearly increase until 150 mm depth at around 700 N per rolling tine and plateaus until the full insertion of 200 mm.

Genetically modified (GM) canola (Brassica napus L.) has been widely adopted in Canada since its commercial release in 1995 and now represents over 85% of the canola grown in western Canada. Concurrently, GM canola volunteers have become an increasing management problem in cultivated fields and are ubiquitous in adjacent ruderal (non-cropped disturbed) habitats. However, systematic post-release monitoring is lacking and the ecological and agronomic impacts of escaped GM canola are poorly understood. In this dissertation, I characterize the escape, demography and distribution of GM canola in ruderal habitats in southern Manitoba, at multiple spatial and temporal scales. I characterized GM herbicide tolerance traits in 16 escaped canola populations. The progeny of 129 plants were tested in herbicide trials; 74% of plants produced glyphosate-tolerant progeny, 63% produced glufosinate-tolerant progeny, and 34% produced multiple herbicide-tolerant progeny as a result of gene flow between escaped plants. At the population-scale, four escaped GM canola populations were monitored and periodic matrix models were constructed to describe the dynamics and persistence of flowering plants. Escaped populations were observed to flower in synchrony with adjacent crops and were projected to persist for 2 to 5 years, confirming the potential for gene flow between escaped and cultivated canola populations. At the landscape-scale, the distribution of escaped canola was surveyed in three agricultural regions. Regional factors were important determinants of distribution; escaped canola density was positively correlated with canola cropping intensity and with traffic intensity, and was negatively correlated with distance to grain distribution centres. Local seed dispersal had negligible impact on distribution compared to landscape-scale anthropogenic seed inputs resulting from agricultural transport. These findings suggest that escaped canola persists as a metapopulation, where long-distan

E. coli O157:H7 has been found to survive in dry sausages and cause disease. Isothiocyanates have been studied for their capacity to eliminate pathogens from foods and are attractive from the consumer perspective because of their natural origin. There is a need to better understand how isothiocyanates kill microorganisms and their behaviour in food matrices. It was found that glutathione and cysteine naturally present in meat can react with AIT, forming a conjugate with no or low bactericidal activity against an E. coli O157:H7. In addition, AIT presented higher anti-E. coli activity at lower pH values; therefore, it should be more efficient in acid foods. AIT was also found to inhibit the activity of thioredoxin reductase and acetate kinase; hence, enzymatic inhibition may represent a way in which AIT kills E. coli O157:H7. Mustard powder is used as a spice (active myrosinase) and/or binder (inactive myrosinase) in meat products. Both of these powders killed E. coli O157:H7 in dry fermented sausage. This was not expected since the powder lacking myrosinase is not able to produce isothiocyanates. Starter cultures and E. coli were found to consume significant amounts of glucosinolates. Pediococcus pentosaceus UM 121P and Staphylococcus carnosus UM 123M (higher myrosinase-like activity) were compared against P. pentosaceus UM 116P + S. carnosus UM 109M for their ability in reducing E. coli viability in dry sausage. Sausage batches containing powders of hot mustard, cold mustard, autoclaved mustard and no powder were prepared. Both pairs of starters yielded similar results. Reduction >5 log CFU/g of E. coli O157:H7 occurred after 31 d for hot powder and 38 d for cold powder; there was no reduction in the control. E. coli O157:H7 itself has greater effect on glucosinolate degradation than either pair of starters, which may be more important in determining its survival. Autoclaved powder caused >5 log CFU/g reduction after 18 d. This may be the result of synergistic/addi

Food protein-derived peptides have increasingly become important sources of ingredients for the formulation of therapeutic products. The main aim of this work was to study the in vitro and in vivo bioactive properties of structurally diverse group of peptides produced through enzymatic hydrolysis of flaxseed proteins (FP). Hydrolysis of FP with seven proteases followed by fractionation into low-molecular-weight (LMW) cationic fractions yielded multifunctional peptides that inhibited angiotensin converting enzyme (ACE) and renin activities, which are molecular targets for antihypertensive agents. The LMW peptides also exhibited antioxidant properties by scavenging free radicals and inhibiting amine oxidase activity. The peptide fractions showed inhibition of calmodulin-dependent phosphodiesterase, an enzyme that has been implicated in the pathogenesis of several chronic diseases. Moreover, FP hydrolysis with thermolysin and pronase followed by mixing with activated carbon yielded branched-chain amino acids (BCAA)-enriched multifunctional peptide mixture (Fischer ratio of 23.65) with antioxidant properties and in vitro ACE inhibition; Fischer ratio of 20.0 is considered minimum for therapeutic purposes. The BCAA-enriched peptide product can be used in clinical nutrition to treat muscle wasting symptoms associated with hepatic diseases. Furthermore, an arginine-rich peptide mixture (31% arginine versus 11% in the original flaxseed protein) was produced by hydrolysis of FP with trypsin and pronase followed by separation using electrodialysis-ultrafiltration. Arginine plays important physiological roles especially as precursor to vasodilator, nitric oxide. The arginine-rich peptide mixture exhibited in vitro ACE and renin inhibition and led to decreased systolic blood pressure (–17.9 and –11.7 mmHg, respectively at 2 and 4 h) after oral administration to spontaneously hypertensive rats. For the first time in the literature, we showed that arginine peptides have superior

Alfalfa is an important forage crop in North America which can also escape cultivation and establish in unmanaged habitats. Genetically modified (GM) alfalfa has been approved for environmental release in Canada and the United States and the occurrence of alfalfa in unmanaged natural and semi-natural habitats may compromise the successful co-existence of GM and non-GM alfalfa. To-date, little information has been available on the nature and dynamics of roadside alfalfa populations and their ability to become feral. Such knowledge is necessary to design efficient trait confinement protocols and to enhance the co-existence of GM and non-GM alfalfa within agricultural regions. The overall aim of this work was to characterize roadside alfalfa populations and to establish their role in novel trait movement. A roadside survey revealed the widespread occurrence of feral alfalfa populations in southern Manitoba. We described the seedbanks of roadside alfalfa populations, seedling recruitment and adult reproductive success, indicating that alfalfa is capable of establishing self-perpetuating feral populations in unmanaged habitats. We also noted the successful establishment of alfalfa in a grass sward representing roadside vegetation. Roadside mowing can reduce (and perhaps prevent) seed production in roadside alfalfa; however, mowing failed to drive the populations to extinction in the short-term. Herbicide (2,4-D) applications controlled alfalfa plants but seeds in the seedbank may still contribute to new seedling recruitment. The roadside alfalfa populations we worked with exhibited high levels of genetic diversity, indicating an absence of past population bottlenecks or genetic drift. In addition, phenotypic characterization provided evidence that roadside alfalfa populations were experiencing selection pressure for adaptive traits including winter survivability, rhizome production and prostrate growth habit; all traits that favor persistence in unmanaged habitats. We al

Incorporation of full-fat flaxseed, and to a lesser extent, canola seed in diets to produce n-3-enriched products has attracted interest in the poultry industry. However, high amounts of nonstarch polysaccharides (NSP) in oilseeds compromise their nutritive value. The objectives of the current research were to develop enzyme supplements effective in cell wall depolymerization and viscosity reduction, particularly in flaxseed; to evaluate the effects of enzyme addition and feed processing on oil utilization and egg n-3 fatty acid deposition in broiler chickens and laying hens fed oilseed-containing diets; to characterize the NSP hydrolysis products and to investigate the effects of diet type and enzyme addition on growth performance and the incidence of necrotic enteritis (NE) in broiler chickens challenged with Clostridium perfringens. Results showed that diets containing high levels of flaxseed reduced egg production and shell quality in laying hens, and impaired final body weight and feed conversion ratio (FCR) in broiler chickens. Reducing flaxseed particle size via grinding did not improve the growth performance of broiler chickens, whereas diet pelleting showed more pronounced and beneficial effects in improving the nutritive value of flaxseed, particularly when intact seeds were used. Multicarbohydrase supplementation resulted in a significant depolymerization of cell wall polysaccharides in soybean, canola and flaxseed meals, which was followed by the production of water-soluble NSP hydrolysis products, and the reduction of flax mucilage viscosity in vitro was also evident. Enzyme addition to flaxseed-containing diets improved FCR of broiler chickens and egg production performance of laying hens, and facilitated egg n-3 fatty acid deposition. The C. perfringens challenge caused intestinal NE lesions and increased the mortality of broiler chickens with the highest NE mortality and intestinal C. perfringens counts observed in those fed flaxseed-containing diets

Verticillium wilt, caused by the soil-borne Verticillium dahliae Klebahn is a serious problem in the production of sunflower worldwide. To date, information on sunflower resistance to Verticillium spp. is very scarce, although it is critical for an effective management of this pathogen. In this study, two highly aggressive (Vd1396-9 and Vd1398-21) and two weakly aggressive V. dahliae isolates (Vs06-07 and Vs06-14) were used to inoculate moderately resistant (IS6111) and susceptible (IS8048) sunflower hybrids. VdNEP (V. dahliae necrosis and ethylene-inducing protein), an elicitor from V. dahliae, was also used to infiltrate sunflower plants. Our results indicate that VdNEP has a dual role in the interaction between sunflower and V. dahliae. VdNEP acted not only as a pathogenicity factor on sunflower by inducing wilting symptoms such as chlorosis, necrosis and vascular discoloration, but also as an elicitor triggering defense responses of the host. VdNEP induced the hypersensitive cell death in Nicotiana benthamiana leaves and sunflower cotyledons. Moreover, VdNEP activated the production of reactive oxygen species and the accumulation of fluorescent compounds in sunflower leaves. Pathogenesis-related genes (Ha-PR-3, and Ha-PR-5), two defensin genes (Ha-PDF and Ha-CUA1) and genes encoding Ha-ACO, Ha-CHOX, Ha-GST and Ha-SCO were up-regulated by VdNEP, suggesting that multiple signaling pathways are involved in this interaction. Two SA-related genes (Ha-PAL and Ha-NML1) were slightly suppressed after infiltration with VdNEP, suggesting a possible involvement of VdNEP in affecting sunflower defenses.

The feasibility of using optical sensors and non-nitrogen limiting reference crops to determine post-emergent nitrogen fertilizer requirements of canola was evaluated. Normalized difference vegetation index was well suited for estimating yield potential and nitrogen status. Although sensor-based nitrogen management was generally agronomically feasible for canola, the economic benefits of doing so remain uncertain because of the added cost of applying post-emergent nitrogen.