Camelina sativa is an oilseed crop that is increasingly used as a source of biopolymer and biofuel. Thirteen accessions were crossed in all pairwise combinations. Some crosses yielded progeny that exhibited best-parent heterosis for traits associated with seed yield, though mid-parent heterosis was more commonly found.

The chemical analysis of market-available white oat cultivars allows for their optimized use for processing, consumption, and in blocks of crosses. The purpose of this study was to evaluate the performance of white oat cultivars with regard to grain chemical content, to estimate the correlation between these traits, and to select potential REMAP markers for marker-assisted selection. Fifteen cultivars, grown in three environments, were evaluated for the contents of proteins; lipids; total, insoluble, and soluble dietary fiber; ß-glucan; and carbohydrates. Eight cultivars were analysed with REMAP markers. The cultivars Brisasul and UPFA Gaudéria presented higher contents of ß-glucan, while cultivars URS 21 and URS 22 had higher protein contents. For animal feed, the cultivars Barbarasul and FAPA Louise stood out with high lipid contents. Positive correlations between the contents of lipid and total dietary fiber, protein and insoluble dietary fiber, and total dietary fiber and insoluble dietary fiber were constant in different environments. Also, carbohydrate content was negatively correlated with protein, total dietary fiber, insoluble dietary fiber, and lipid content. A total of thirteen REMAP combinations were selected for variability studies regarding lipid and ß-glucan contents.

Because of their wide applications in manufacturing life science and medicine, nanoparticles (NPs) are becoming potential limiting factors for agricultural plant growth and productivity. Thus, development of some low cost and low risk methods for detoxifying or alleviating cytotoxicity of NPs on crops would be a proactive attractive solution. In this study, we investigated the ameliorating effect of He-Ne laser illumination of seedlings on cytotoxicity of cadmium sulfide nanoparticles (CdSNPs) in tall fescue seedlings. Physiological parameters and biochemical characteristics of 20-d-old seedlings with different times of laser illumination and graded doses of CdSNPs treatment, either alone or in combination, were measured. Cadmiun sulfide nanoparticles exhibited pronounced inhibitory effect on shoot and root growth, respectively. Accumulation of CdSNPs in plant root cells resulted in oxidative stress as detected by the formation of reactive oxygen species (ROS), which aggravate the cytotoxicity of CdSNPs on seedlings. Treatment of seedlings with CdSNPs alone also reduced antioxidant concentration, phytochelatins (PCs) content, enzymatic activities of phytochelatin synthase (PCS), and antioxidant enzymes, such as CAT, APX, GR, and POD, except SOD. However, He-Ne laser illumination prior to CdSNPs exposure alleviated the inhibitory effect on seedling growth and development through activation of tall fescue antioxidant systems due to induction of antioxidants biosynthesis and antioxidant enzyme activities. Furthermore, PCs and GSH induced by laser was also demonstrated to be involved in decreasing the cytotoxicity of CdSNPs through binding free cadmium ions release from CdSNPs. The interactive mechanisms between He-Ne lasers, plant antioxidant systems, and PCs biosynthesis pathways need be further investigated.

Seeds of many forage species have dormancy, delaying germination in the field. Species from semi-arid environments may have adaptation to fire, therefore, the effects of priming seeds of common forage species in aqueous smoke solutions were studied. Seeds of eight grasses and two legumes were primed in serial dilutions of aqueous smoke solutions and then dried before germination tests. Depending on the species and concentrations of solutions, priming seeds acted independently or in interaction with light and (or) temperature to improve germination in Altai wildrye (Leymus angustus), green needlegrass (Nassella viridula), Kura clover (Trifolium ambiguum), needle-and-thread (Hesperostipa comata), northern wheatgrass (Elymus lanceolatus), orchard grass (Dactylis glomerata), plains rough fescue (Festuca hallii), Russian wildrye (Psathyrostachys juncea), and western wheatgrass (Pascopyrum smithii). Priming seeds of cicer milkvetch (Astragalus cicer) in distilled water or aqueous smoke solutions had no effect on germination (P > 0.05). Priming seeds in aqueous smoke solutions partially substituted the light requirement for germination in seven species. Priming seeds in aqueous smoke solutions before sowing in the field did not change total seedling emergence (P > 0.05), but increased standing crop for orchard grass and Plains rough fescue. Overall, the beneficial effects of priming in smoke solutions on perennial age species are less than species from environments adapted to more frequent fires.

Cyclic lipopeptides (CLPs) derived from plant growth-promoting rhizobacteria (PGPR) are well known as potential antifungal compounds. However, the physiological function of CLPs from Bacillus vallismortis strain EXTN-1 (EXTN-1) is still poorly understood. In this study, we proposed the potential role of iturin A analogs in modulation of induced systemic resistance (ISR) of chili pepper in response to Phytophthora capsici. Seven individual iturin A analogs were identified from EXTN-1, and iturin A analogs pre-treated plants resulted in a significant reduction of disease. However, no iturins directly inhibited growth of P. capsici in vitro antibiosis assay, indicating the existence of other possibilities for suppression of disease. The expression analysis of defense-related marker genes PR1, PR4, PR10, chitinase, peroxidase, and ß-1,3-glucanase revealed that transcript levels of these genes were dramatically up-regulated in iturin A analog treated plants after inoculation of P. capsici, suggesting that iturin-triggered plant systemic defense responses were involved in attenuating the disease symptoms. Collectively, our results clearly suggest that iturin A analogs from EXTN-1 are required for alleviation of P. capsici-mediated disease incidence.

An efficient procedure for the micropropagation and conservation of cherry birch (Betula lenta L.), an endangered species in Canada, is reported. The model utilizes in vitro proliferation of fresh and dormant buds from both greenhouse and mature trees. Various factors were evaluated to optimize the protocol, including plant growth regulators, type and concentration of carbohydrates, and the composition of basal salts. 6-benzylaminopurine was the most effective cytokinin for shoot multiplication, with an optimal concentration of 5 µM. Sucrose was a more effective carbohydrate source than glucose, with the highest multiplication rate occurring at 3% sucrose (w/v). Shoot multiplication was similar on Murashige and Skoog (MS) and Driver and Kuniyuki Walnut (DKW) basal salts, but significantly lower on Woody Plant medium (WPM). Culture media with half-strength DKW basal salts and 20 µM indole-3-butyric acid was found to be the best for rooting (80%). Rooted plantlets were acclimatized to the greenhouse environment with a 37% survival rate. The micropropagation technology developed in the study offers excellent opportunities and tools for rapid replenishment of cherry birch trees in their natural environment, long-term conservation, and provides a platform for further research of this nationally endangered species.

Pink snow mould caused by Microdochium nivale is a serious cereal and grass disease in several temperate regions. In this study, resistance to snow mould was evaluated under controlled conditions in nine promising breeding populations and two cultivars of Festulolium, three cultivars of Festuca pratensis, six cultivars and two breeding populations of Lolium perenne and one cultivar of hybrid ryegrass using non-hardened plants. In addition, winter survival was evaluated in field plots inoculated with M. nivale. Under controlled conditions, tetraploid entries of Festulolium had a significantly better resistance to snow mould than diploid entries in three out of four tests. Diploid and tetraploid entries of L. perenne showed similar levels of resistance under controlled conditions. In the field trial, entries of both L. perenne and Festulolium that had been exposed to natural selection in northern Norway (above 65°N) showed good levels of winter survival. In general, under controlled conditions snow mould resistance of Festulolium entries was associated with ploidy level, whereas under field conditions winter survival of L. perenne entries was associated with their degree of northern adaptation. However, resistance to snow mould in non-hardened plants tested under controlled conditions was not correlated with winter survival in the field.

Red sorrel is a common weed in lowbush blueberry fields in Nova Scotia, Canada. Grower experience suggests that high red sorrel density necessitates fungicide applications to control Botrytis cinerea, a major fungal pathogen in lowbush blueberry. Specific interactions between red sorrel, lowbush blueberry, and B. cinerea, however, remain unclear. Experiments were conducted in Nova Scotia to determine the (1) presence or absence of red sorrel pollen on lowbush blueberry flowers in the field, (2) impact of red sorrel pollen on in vitro B. cinerea spore germination and infection of immature and mature blueberry flowers, and (3) effect of pronamide applications on red sorrel and lowbush blueberry growth. Red sorrel pollen grains were found on blueberry flowers in the field. In vitro B. cinerea spore germination increased with increasing red sorrel pollen concentration, with the relationship adequately explained by a 3-parameter exponential rise to a maximum equation. Red sorrel pollen increased B. cinerea disease incidence on immature, but not mature, blueberry flowers in the greenhouse. Pronamide applications reduced red sorrel density in three out of four site years, but did not reduce red sorrel biomass or increase harvestable blueberry yield. Red sorrel pollen may increase B. cinerea disease incidence in lowbush blueberry, and growers should expect variable results when using pronamide for red sorrel management.

Soil flooding and submergence, collectively termed waterlogging, are major abiotic stresses that severely constrain crop growth and productivity in many regions. Cool-season grain legumes can be exposed to submersion both at the vegetative and reproductive stages. Limited research has been carried out on these crops with waterlogging imposed at flowering. We evaluated how waterlogging periods of 0, 5, 10, 15, and 20 d at flowering affected seed yield, biomass of shoots, roots and nodules, and N uptake of faba bean (Vicia faba L. var. minor), pea (Pisum sativum L.), and white lupin (Lupinus albus L.). Faba bean tolerated submersion better than pea and white lupin. Pea and white lupin plants did not survive 10 d of submersion, and after 5 d the seed yield, shoot and root biomass, and N uptake had more than halved. Faba bean survived 20 d of waterlogging, although seed and biomass production and total N uptake were severely reduced. Shoot dry weight and seed yield decreased linearly with the duration of waterlogging, which negatively affected seed more than the vegetative plant part weight. In all three crops waterlogging at flowering led to damage, which could not be recovered during seed filling.

Strawberry fruits are perishable due to fruit softening occurring during storage and marketing, but the mechanism by which this occurs is not clear. In this study, the possible mechanism of softening is explored by comparative studies on the changes of fruit firmness, pectate lyase (PL) activities, and relative expression levels of PL genes between two strawberry cultivars. The results indicate that a method for the determination of PL activity in the strawberry fruit was established. The activity of PL was at a low level in the small green fruit to white fruit stage, and maintained at a high level in the ripening and softening stage. The PL gene was specifically expressed in fruit and mainly in the ripening stage. PL expressions were closely correlated with PL activities, and negatively related with the changes in flesh firmness. The full-length cDNA of PL genes from the two cultivars was cloned using the RACE method. Amino acid residues of C terminal sequences of the PL proteins from different species showed significant variations. Those results suggested that the differences in PL activity, gene sequence, and gene expression patterns may lead to the different roles of PL in different fruit textures of strawberries during ripening and softening.

Laboratory and greenhouse experiments were conducted to compare the effects of agronomic and environmental factors on germination and emergence of glyphosate-resistant (GR) hybrid corn (Mycogen 2G681) and its progeny. The germination of GR hybrid corn and its progeny was 84% to 97% at day/night temperatures of 15/10 °C to 42.5/30 °C, while higher (45/35 °C) and lower (0/0 °C) temperatures reduced germination to ≤6%. Germination was >90% at all alternating as well as constant light and dark periods at a fixed day/night temperature of 30/20 °C. At osmotic stress level of 0 to -0.3 MPa, >90% of hybrid corn and progeny seeds germinated, while osmotic stress level of -0.4 to -1.3 MPa reduced germination to <65%. Greater than 90% germination was observed at a wide range of salt concentrations (0-160 mM), with the lowest germination (53%) at 320 mM. More than 87% cumulative seedling emergence of hybrid corn and its progeny occurred at a depth of 0.5-6 cm and hybrid corn emergence reduced from 86% to 23% compared with 21% to 2% reduction of progeny at 1 and 2 d of flooding, respectively.

The objective of this study was to investigate the effects of delayed controlled atmosphere (CA) storage on fruit quality and disorders in temperature conditioned ‘Honeycrisp’ apples. For three consecutive years, ‘Honeycrisp’apples were harvested from the same commercial orchard and conditioned for 4 d at 12-19 °C immediately after harvest. Apples were then held in ambient air at 3 °C for 0, 2, 4, 8, or 14 wk, followed by CA storage (3 kPa O₂ and 1.5 kPa CO₂) at 3 °C for 6 or 7 mo of total storage time. The effect of 1-methylcyclopropene (1-MCP; 1 µL L^-1) was also investigated. Delaying the establishment of CA reduced the incidence of internal CO₂ injury, with or without flesh cavitation. Furthermore, higher incidence of CO₂ injury required longer delay of CA to reduce the disorder. In some years, delayed CA also resulted in increased lenticel breakdown, bitter pit/blotch and greasiness. 1-MCP treatment reduced lenticel breakdown when CA establishment was delayed 4 wk or more. There was variation in fruit firmness among years and durations of CA delay, and some increase in firmness was observed during storage. 1-MCP-treated fruit showed little change in firmness with delayed CA. There was also little effect of delayed CA on internal ethylene concentration (IEC), soluble solids concentration (SSC), and malic acid content. These results suggest that conditioning and delaying CA storage reduces the incidence of internal CO₂ injuries in ‘Honeycrisp’ apples, but the delay may aggravate other disorders.

Our previous study revealed that proline (Pro) accumulated in peach trees when cold-acclimated shoots were exposed to higher temperatures. In this study, we determined whether such Pro accumulation is indeed a high temperature-stress response or metabolic preparation for growth resumption. Two studies were conducted to address this question using ‘Daewol’ peach trees. In study 1 (February), Pro content of eco-dormant shoots increased when cold-acclimated plants were exposed to two heat treatments (HTs) but remained unchanged during the intervening cold treatment (CT). Concurrently, ornithine-delta-aminotransferase (OAT) and Δ¹-pyrroline-5-carboxylate reductase (P5CR) genes were up- and down-regulated after two HTs and the CT, respectively. Study 2, conducted with growing trees (May), showed that Pro did not change and expression of P5CR and OAT was down-regulated when trees were subjected to either HT or CT; HT and CT used here constituted ‘stress’ treatments as revealed by the decline in chlorophyll fluorescence. Taken together, these results suggest that Pro accumulation (study 1) may be associated with the preparation for growth resumption and not ‘stress’. Furthermore, results from parallel gene expression studies suggest that the ornithine, rather than glutamate, pathway may be the primary Pro biosynthesis route both during growth resumption and high temperature stress in ‘Daewol’ peach.

Global food demand has risen continuously because of increasing population with greater food and energy needs. Corn production, however, is constrained by current and possible increased future variability in the weather. Earlier planting is a strategy for U.S. Mid-South corn producers to avoid typical summer droughts. However, planting early will increase the likelihood of seedlings exposure to cold temperatures. The objectives of this study were to evaluate corn hybrids planted when the conditions are desirable followed by low and moderately low temperatures to assess the variability among the vegetative and physiological parameters and to classify hybrids into different cold tolerant groups. Twenty one commercially-grown hybrids were subjected to three day/night temperature treatments; 29/21 °C (optimum), 25/17 °C (moderately low), and 21/13 °C (low) from 15 d after planting (DAP) for plants grown at optimum temperature. Shoot, root, and physiological parameters were measured, 32-34 DAP. Significant differences and interactions were observed among the temperature treatments and hybrids for most of the traits measured. Based on relative scores, developed in this study, AR1262 and P1636YHR were classified as cold tolerant and H68B and ST11504VT3 as cold sensitive. Cold tolerant hybrids and their associated morpho-physiological characteristics may be useful for breeders to develop new hybrids that could withstand low and variable temperatures during seedling growth and developmental period.

Populations of glyphosate-resistant (GR) Canada fleabane and GR giant ragweed can be found in several locations in southwestern Ontario. While these species can be managed individually, a scenario has developed where both species are present in GR soybean. Ten separate field experiments (five with Canada fleabane and five with giant ragweed) were conducted over a 2-yr period (2013-2014) in soybean to evaluate preplant (PP) herbicide tank mixtures that could control both weed species if they were present in the same field. Herbicides were rated for soybean injury, weed control, population density, and aboveground biomass. Two- and three-way tank mixtures containing amitrole (i.e., glyphosate amitrole, glyphosate amitrole saflufenacil, and glyphosate amitrole 2,4-D) were among the most effective treatments. For example, control of GR Canada fleabane and GR giant ragweed was at least 92% at 4 wk after treatment (WAT) and weed density and biomass were generally similar to the weed-free control. However, without amitrole, the best PP herbicide option was a three-way tank mixture of glyphosate saflufenacil 2,4-D which provided improved control and greater reductions in density and biomass compared with the two-way glyphosate tank mixtures containing saflufenacil or 2,4-D.

The strawberry production season can be extended in Ontario if plantings are protected from adverse weather conditions. At present, dayneutral cultivars developed in California are used for production, but are not well adapted to Ontario conditions. The objectives of this study were to determine suitable dayneutral cultivars for production throughout Ontario and to investigate how they react to high tunnel environments. Two sets of trials were run. The first set, planted in 2005 and harvested in 2005-2006, compared six dayneutral cultivars of strawberries in four environments. The second set, planted in 2010 and harvested in 2010-2011, compared five dayneutral cultivars grown in four environments. For the summer crops, high tunnels had higher yields in the cooler environment at New Liskeard and low yields in the warmer environment of Cedar Springs, when compared with outside plantings. In the spring, this trend was reversed. ‘Seascape’ and ‘Tribute’ performed consistently in all environments. ‘Albion’ and ‘Monterey’, although medium yielding with lower winter survival, had large fruit size and exceptional fruit quality. ‘Portola’, had large fruits and performed well, so could be of interest to farmers in Ontario. All the European cultivars tested had medium to small berries.

A soil test N (STN) is required to implement N fertilizer recommendations for vegetable crops in cultivated organic soils. A STN can be developed using the isometric log ratio (ILR) to balance soil C, N, and other soil components amalgamated into a filling value (F_v) and to derive a Mahalanobis distance () as STN. Our objective was to conduct a meta-analysis of multi-year and multi-site N trials on lettuce (Latuca sativa L.) response to added N along a gradient of values, and to develop an N recommendation model. Twenty-four N fertilization experiments were conducted from 2002 to 2006 in organic soils of southwestern Quebec. Each crop received four N rates from zero to 120-150 kg N ha^-1 applied before seeding or in split applications. The relationship between N requirements by lettuce and STN was quadratic whether lettuce was seeded or planted. There were three STN fertility classes delineated by values of 1 and 5.5. The N recommendation model and its uncertainty were valuable for values up to 8.4. This approach provides a reliable test soil N to implement appropriate fertilizer recommendations for lettuce in organic soils.

Euphorbia lagascae and Centrapalus pauciflorus are natural sources of the plasticizer vernolic acid, and are therefore being considered as potentially new industrial oilseed crops in Canada. Both species show a propensity to grow in undisturbed and unfavourable conditions in their native regions of southern Europe and Africa. Trials were conducted in Ontario between 2013 and 2014 to better understand the biology of these species. The ability of these species to establish, leave a seedbank, and compete with a crop was explored. C. pauciflorus emergence in cultivated seedbeds (5.14%-12.15%) was higher than in mowed (0.99%-1.87%) and undisturbed grass (0.00%-0.25%) in spring 2014. E. lagascae also emerged at higher rates in cultivated seedbeds (3.07%-4.98%) than mowed (0.88%-1.99%) or undisturbed grass (0.22%-1.00%) in spring 2014, however emergence was higher in mowed grass (6.25%) than seedbeds (4.00%) in fall 2014. The low persistence of seeds in the soil (93%-100% seeds were nonviable) and poor ability to establish a seedbank limit their potential as weeds. Plants that established in unmanaged areas did not produce viable seeds and are therefore unlikely to become weeds. Even though their competitive ability is similar to that of redroot pigweed on a plant per plant basis, they are unlikely to achieve the high densities and persistence of pigweed infestation and are unlikely to threaten farms as weeds.

Swath-grazed oat (Avena sativa L.) and stockpiled meadow bromegrass (Bromus riparius Rhem) were compared with (Control) a pen-fed straw-based total mixed ration (TMR) for dry, pregnant beef cows (670 ± 88 kg BW) using carrying capacity, nutritive value, cow performance, daily feeding, yardage, and total daily costs. Carrying capacity ranked (P < 0.05): oat (637 cow-d ha^-1) > Control (454 cow-d ha^-1) > stockpiled grass (189 cow-d ha^-1). In vitro true digestibility (IVTD) ranked (P < 0.05): stockpiled forage (681 g kg^-1) > oat (588 g kg^-1) > Control (530 g kg^-1). Average cow body condition score (BCS) off pasture was (P < 0.05): stockpiled grass (3.4) > oat (3.0), while the control was intermediate (3.3). The daily feed cost ranked: stockpiled grass ($0.38 cow-d^-1) < swathed oat ($0.48 cow-d^-1) < Control ($1.05 cow-d^-1). Yardage (non-feed costs) ranked: oat ($0.41 cow-d^-1) < stockpiled ($0.50 cow-d^-1) < Control ($0.91 cow-d^-1). Total daily cost was similar for oat ($1.07 cow-d^-1) and stockpiled grass ($1.04 cow-d^-1), both less (P < 0.05) than the control ($2.25 cow-d^-1). The cost of both grazing treatments was comparable to other research, but the stockpiled treatment cost was limited by the low yield of forage regrowth.

Cultivated potatoes (Solanum tuberosum L.) are the 4th most important crop feeding the world. Therefore, yield is a crucial trait for potato breeding and germplasm enhancement. The analysis of phenotype data of potato plants enables the extraction of crucial phenotypic characters for potato yield breeding. Using data collected from 179 advanced breeding clones that were planted in evaluation trials over three years at the Benton Ridge breeding substation in Atlantic Canada, we deciphered the dynamic properties of trait expression over the growth period based on nine parameters used in Agriculture and Agri-Food Canada's potato breeding program. The analysis of breeding data provided valuable information to understand the factors that contribute to the phenotypic performance of potato and potato tuber yield. Linear mixed model fit by maximum likelihood and principal component analysis (PCA) were employed as complementary analysis tools to analyze these characters to try to uncover the relationship of complex agronomic traits. Our results showed that the majority of the selection parameters effectively contributed to the improvement of potato tuber yield. The first five principal components (PCs) accounted for 74.9% of the phenotypic variation observed from 2012 to 2014. The maturity, early vigor, eye depth, and top vigor are the most important phenotypic parameters affecting potato tuber yield selection. Based on the results, these selection parameters are yet highly independent variables which also displayed some degree of interrelationship.

HYHEAR 2 summer rape (Brassica napus L.) is the world's second hybrid Roundup Ready^® high erucic acid, low glucosinolate cultivar. On average, HYHEAR 2 yielded 12% more seed, 4 g kg^-1 more seed oil, but 8 g kg^-1 less meal protein than Red River 1861 Roundup Ready^® high erucic acid, low glucosinolate summer rape. HYHEAR 2 has an erucic acid content of 51.6% in isolated field trials of HEAR lines and is adapted to the southern B. napus growing regions of western Canada.

CO456 is a short season corn (Zea mays L.) inbred line with excellent combining ability as well as moderate resistance to eyespot and intermediate resistance to common rust and fusarium stalk rot. Excellent hybrid yields and performance data were achieved when CO456 was combined with Iodent-type inbreds such as MBS8148 and TR1914.

AAC Durafield durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) is adapted to the durum production area of the Canadian prairies. AAC Durafield combines agronomic traits comparable to the widely adopted cultivar Strongfield with high semolina yield, high semolina yellow pigment, strong gluten, and low grain cadmium concentration.