Vigneault, C., Leblanc, D. I., Goyette, B. and Jenni, S. 2012. Engineering aspects of physical treatments to increase fruit and vegetable phytochemical content. Can. J. Plant Sci. 92: 373–397. The levels of phytochemicals in fruit and vegetables are affected by many preharvest and postharvest factors, such as cultivars, farming practices, environmental conditions, harvest techniques, and postharvest handling and treatment. Postharvest factors are generally the easiest to manage since produce handling takes place mainly under controllable conditions. Although specific physical treatments, such as heat and ultraviolet radiation, have been developed to increase the phytochemical content of horticultural produce, very little information is available on the engineering aspects of these treatments. A review of the engineering aspects related to phytochemical-enhancing physical treatments was undertaken to identify the process parameters required to obtain repeatable results, the basic information required for scale-up of the process, and the key parameters required to ensure appropriate monitoring and control of commercial applications. The uniformity, efficiency, efficacy, ease of control and ease of scale-up of various physical treatments were compared to support the development of a new phytochemical-enhancing treatment for potential commercial application. These treatment methods were considered independently of the physical characteristics of the produce treated (type of produce, size, shape, and positioning) to reduce the number of parameters to be studied with a view to scale-up processes, following identification of the optimal processing conditions through laboratory-scale testing.

Mokhele, B., Zhan, X., Yang, G. and Zhang, X. 2012. Review: Nitrogen assimilation in crop plants and its affecting factors. Can. J. Plant Sci. 92: 399-405. In this review we discuss mainly nitrogen assimilation in crop plants and factors affecting the related process. Nitrogen is a major macro-element limiting the growth and development of plants in agriculture. Both organic and inorganic forms of nitrogen are metabolized in plants; nitrate and ammonia in soil are common forms of inorganic nitrogen that can be metabolized in all plants. There are other nitrogen forms, which include amino acids, nitrite and urea, that are metabolized in plants. Metabolism normally starts with reduction of nitrate to nitrite, and the latter further reduces to form ammonium with the presence of relevant enzymes. This reaction occurs more rapidly in leaves in the presence of light. After ammonia is formed, it enters into the biosynthetic pathways of plant cells, such as reductive amination and transpiration, to produce different amino acids. Amino acids in cells take part in the synthesis of protein and other nitrogenous compounds that help in body building. Radiation, gaseous factors, the presence of metals, soil pH and amount of nitrate are some of the environmental factors affecting absorption and reduction of nitrogen in plants. This review presents a comprehensive understanding of the assimilation process by crop plants of nitrogen and recommends that favorable surrounding conditions are the prerequisites for plants to absorb and utilize nitrogen efficiently.

Thilakarathna, S. H. and Rupasinghe, H. P. V. 2012. Anti-atherosclerotic effects of fruit bioactive compounds: A review of current scientific evidence. Can. J. Plant Sci. 92: 407–419. Atherosclerosis is a condition which leads to a cascade of processes involved in thickening of arterial walls as a result of fatty deposition, which can increase the risk of cardiovascular diseases. Among numerous remedies, the consumption of fruits is believed to have beneficial effects on atherosclerosis development. Various bioactive compounds are present in fruits and they have been found to be responsible for exerting these beneficial effects. Fruit flavonoids and certain terpenoids are among the most efficacious fruit bioactive compounds that have shown positive effects on different in vitro as well as in vivo research models of atherosclerosis. The mechanisms of actions of these compounds vary from exerting antioxidant activities to anti-atherogenic and lipid lowering activities, based on different experimental models. This review article briefly explains how some of the fruit bioactive compounds have affected atherosclerosis under experimental conditions.

Wang, H., He, Y., Qian, B., McConkey, B., Cutforth, H., McCaig, T., McLeod, G., Zentner, R., DePauw, R., Lemke, R., Brandt, K., Liu, T., Qin, X., White, J., Hunt, T. and Hoogenboom, G. 2012. Short Communication: Climate change and biofuel wheat: A case study of southern Saskatchewan. Can. J. Plant Sci. 92: 421–425. This study assessed potential impacts of climate change on wheat production as a biofuel crop in southern Saskatchewan, Canada. The Decision Support System for Agrotechnology Transfer-Cropping System Model (DSSAT-CSM) was used to simulate biomass and grain yield under three climate change scenarios (CGCM3 with the forcing scenarios of IPCC SRES A1B, A2 and B1) in the 2050s. Synthetic 300-yr weather data were generated by the AAFC stochastic weather generator for the baseline period (1961–1990) and each scenario. Compared with the baseline, precipitation is projected to increase in every month under all three scenarios except in July and August and in June for A2, when it is projected to decrease. Annual mean air temperature is projected to increase by 3.2, 3.6 and 2.7^°C for A1B, A2 and B1, respectively. The model predicted increases in biomass by 28, 12 and 16% without the direct effect of CO₂ and 74, 55 and 41% with combined effects (climate and CO₂) for A1B, A2 and B1, respectively. Similar increases were found for grain yield. However, the occurrence of heat shock (>32^°C) will increase during grain filling under the projected climate conditions and could cause severe yield reduction, which was not simulated by DSSAT-CSM. This implies that the future yield under climate scenarios might have been overestimated by DSSAT-CSM; therefore, model modification is required. Several measures, such as early seeding, must be taken to avoid heat damages and take the advantage of projected increases in temperature and precipitation in the early season.

Ma, B. L. and Dwyer, L. M. 2012. Changes in kernel characteristics during grain filling in silage-specific and dual-purpose corn hybrids. Can. J. Plant Sci. 92: 427–439. Silage-specific corn (Zea mays L.) hybrids have been gaining in popularity in recent years, but there is a lack of information about the difference in kernel characterization between Leafy silage-specific and dual-purpose hybrids. A field study was conducted for 4 yr to determine the changes in kernel moisture content, kernel dry weight, kernel nitrogen (N) and phosphorus (P) concentrations over the period of grain filling for Leafy silage-specific and dual-purpose hybrids at two plant population densities. In both types of hybrids, kernel dry weight content increased rapidly from approximately 2 wk after silking and reached a maximum at about 50 to 68 d after silking. While some differences among hybrids in kernel maximum dry weight were noted (P<0.05), there was no distinction between hybrid types. The coefficients of kernel moisture change differed greatly between the two types with lower rates of decline of kernel moisture in some of the Leafy silage-specific hybrids (down-hill slope b<0.0136±0.00044 g kg^-1 d^-1) than the dual-purpose or silage hybrids without the Leafy characteristic (b≥0.0164±0.00039 g kg^-1 d^-1). Higher plant population density had a negligible effect on kernel moisture decline and N and P concentrations, but reduced kernel dry weight by up to 7% in one year. Kernel P was linearly positively correlated with N content (r>0.79, P<0.01), and there was a linear relationship between kernel moisture and the whole-plant silage moisture content (R²≥0.70). Our data also showed that one of the Leafy silage-specific hybrids had higher rates of kernel dry weight accumulation and softer kernel hardness (P<0.05) than the dual-purpose or non-Leafy silage hybrids. Our findings on the distinct characteristics of hybrid types are important considerations for corn producers to choose suitable hybrids and make decisions on silage harvest dates.

Ward, C. I., Lardner, H. A. and Jefferson, P. G. 2012. Short Communication: Etiolated growth of hybrid bromegrass (Bromus inermis×B. riparius) compared with smooth bromegrass, meadow bromegrass, crested wheatgrass and tall fescue under grazed or nongrazed conditions. Can. J. Plant Sci. 92: 441-445. Etiolated spring regrowth of hybrid bromegrass was compared with smooth bromegrass, meadow bromegrass, crested wheatgrass and tall fescue under beef steer (Bos taurus) grazed or nongrazed conditions in the previous season over 2 yr in 2006 and 2007. Hybrid bromegrass seeded in 2003 had greater energy reserves than old crested wheatgrass (control) and similar reserves to tall fescue and crested wheatgrass. Hybrid bromegrass can be grazed in similar systems as meadow bromegrass and be expected to maintain sufficient energy reserves for spring growth.

Cho, H. Y., Hwang, S.-G., Kim, D. S. and Jang, C. S. 2012. Genome-wide transcriptome analysis of rice genes responsive to chilling stress. Can. J. Plant Sci. 92: 447–460. Low temperature is known to be one of the major challenges to rice production. We have selected chilling-tolerant TILLING of Donganbyeo, which showed significantly vigorous growth relative to wild-type plants under chilling stress conditions (10–12°C). We performed a comparative transcriptome analysis using a chilling-tolerant line and wild-type plant with the objective to evaluate genomic responses to chilling stress and to identify chilling inducible genes. Functional enrichment analysis results demonstrated that a large proportion of chilling-inducible genes were associated with certain biological pathways, e.g., monosaccharide catabolic processes, reflecting the energy requirements necessary for adaptation to sub-optimal temperatures in plants. Extremely low correlation coefficients in a range of -0.07 to 0.04 were detected between plant responses to chilling stress and different abiotic stress conditions such as drought, salt, cold, and heat; these results imply that plants might exploit strikingly different response mechanisms against stress conditions. The largest subnetwork, which was composed of 78 chilling-specific inducible genes, was found in the tolerant plants, but not in the wild-type plants, which probably implies the existence of a delicate and harmonious signaling pathway setup in the tolerant plants. Expression patterns of 20 chilling-responsive genes were assessed via abiotic stress treatments and phytohormone treatments. About 80% of the tested chilling-inducible genes were upregulated by exogenous abscisic acid (ABA) treatment. The results of this study may prove useful in elucidating the chilling-response pathway and in the development of chilling-tolerant rice varieties.

Yang, J., Yoon, H.-S. and Pak. J.-H. 2012. Phylogeny of Korean Rubus(Rosaceae) based on the second intron of the LEAFY gene. Can. J. Plant Sci. 92: 461–472. The second intron of the LEAFY gene was used for phylogenetic analysis of Rubus (Rosaceae). The LEAFY gene is conserved among a wide variety of plants and is known to be involved in the morphological evolution of plants. Sequence comparison of LEAFY homologues revealed the phylogenetic relationships of previously unresolved taxa, suggesting the usefulness of this marker rather than the ITS region for representing nuclear gene trees. In addition, a combined analysis of the trnL/F intergenic region of chloroplast DNA and the second intron of the LEAFY gene yielded more imformative data. Based on the data, it was inferred that evolution proceeded from herbs to woody plants, compound leaf to simple leaf, and pink petal to white petal within Korean Rubus taxa. Moreover, the LEAFY and trnL/F combined phylogeny had similar topology with the Rubus classification based on morphological characteristics. Therefore, our results indicate that LEAFY and trnL/F were valuable regions for analyzing the phylogenetic relationships among the Rubus taxa in Korea.

Drapeau, R. and Charlebois, D. 2012. American elder cultivation under cold climates: Potential and limitations. Can. J. Plant Sci. 92: 473–484. The hardiness, development, fruit yield and anthocyanin content of six American elder (Sambucus canadensis L.) cultivars from an orchard in a relatively cold area (Normandin, QC) were evaluated over a 7-yr period. Although the study site was located further north than this species' natural range, the six cultivars tolerated the climatic conditions well and exhibited good growth. Fruit production was moderate in the first 2 yr after planting and then hovered around 5 kg per plant in the following 2 yr for all cultivars except for the wild ecotype. The short growing season under Normandin's climatic conditions limited fruit maturation, however. The fruits produced in Normandin generally had a lower anthocyanin content than their counterparts produced in L'Acadie, in southern Quebec. The selection or development of early cultivars or the production of flowers should therefore be recommended in cold climates. Conversion of the biomass produced during pruning could be considered as an additional source of revenue. The results of this study demonstrate, for the first time, the production potential of American elder in orchards under climatic conditions comparable with those in the Saguenay-Lac-Saint-Jean region.

Hu, C., Tsao, R., Liu, R., Sullivan, J. A. and McDonald, M. R. 2012. Influence of cultivar and year on phytochemical and antioxidant activity of potato (Solanum tuberosum L.) in Ontario. Can. J. Plant Sci. 92: 485–493. Phytochemicals in coloured vegetables are responsible not only for the colour, but also for nutritional quality. In this study 11 cultivars of potato, with a wide range of skin and flesh colours, grown over two years were tested for the total phenolic content (TPC), total anthocyanin-content (TAC) and total antioxidant activity (TAA). Results showed significant variations among cultivars for both years. TPC was 1.2–3.6 mg gallic acid equivalent (GAE) g^-1 dry weight (DW) in 2008 and 0.98–2.81 mg GAE g^-1 DW in 2009. Total anthocyanin content was 0.70–1.92 mg cyanidin-3-glucoside equivalent (Cy3g E) in 2008 and 0.05 –1.52 mg Cy3g E g^-1 DW in 2009, respectively. The TAA also varied among different potato cultivars, with values of 12 to 64 and 6.3 to 20 µmol ascorbic acid equivalents (AAE) g^-1 DW in 2008 and 2009, respectively for the FRAP (ferric reducing/antioxidant power) assay, and from 42 to 168 and 75 to 174 µmol trolox equivalents (TE) g^-1 DW in 2008 and 2009 in the ORAC (oxygen radical absorption capacity) assay, respectively. The purple fleshed tubers, such as “Mackintosh Black’, demonstrated the highest antioxidant activities, indicating that anthocyanins are important antioxidants. Our results suggest that purple/red potato cultivars have a greater potential as functional foods for enhanced human health benefits.

Wei, C. B., Wu, Q. Y., Yang, Y. and Liu, C. Y. 2012. Prokaryotic expression of a Thunberg fritillary mosaic virus CP gene and antiserum preparation. Can. J. Plant Sci. 92: 495–500. Fritillariaanhuiensis is a valued traditional Chinese medicinal plant. Thunberg fritillary mosaic virus (TFMV) was found to cause mosaic symptoms. Virus particles of the Lu'an isolate were purified and its RNA genome was extracted. cDNA was synthesized from the RNA and specific PCR primers were used to amplify the virus coat protein (CP) gene. It shared 96.8% nucleotide identity and 97.6% amino acid identity with the sequences of CPs from the other TFMV isolates. The CP gene was inserted into pSBET and expressed in Escherichia coli BL21 (DE3) plys S strain. The expressed protein was first purified by 12% (wt/vol) SDS-PAGE and subsequently by 5–20% (wt/vol) gradient SDS-PAGE. Antiserum against the CP was raised in mouse and its specificity was confirmed by Western blot analysis suggesting that it may be useful for detecting the virus.

Hasan, M. J., Strelkov, S. E., Howard, R. J. and Rahman, H. 2012. Screening ofBrassicagermplasm for resistance toPlasmodiophora brassicaepathotypes prevalent in Canada for broadening diversity in clubroot resistance. Can. J. Plant Sci. 92: 501–515. Clubroot disease of crucifers, caused by Plasmodiophora brassicae, poses a threat to the Canadian canola industry, and the development of resistant cultivars is urgently needed. Germplasm resistant to local pathotype(s) is the prime requirement for breeding clubroot-resistant cultivars. The objective of this study was to identify Brassica germplasm possessing resistance to P. brassicae pathotypes prevalent in Alberta. Pathotype-specific resistance was identified in the diploid species Brassica rapa (AA) and B. oleracea (CC), and in the amphidiploid B. napus (AACC). Among B. rapa genotypes, turnip was the most resistant, followed by winter type and spring type oilseed rape. The rutabaga group of B. napus, on the other hand, was homogeneous for resistance to Canadian P. brassicae pathotypes. The diploid species B. nigra (BB) also showed pathotype-specific resistance. However, the two amphidiploids carrying the B. nigra genome, B. juncea (AABB) and B. carinata (BBCC) were completely susceptible to clubroot.

Miller, R. T., Soltani, N., Robinson, D. E., Kraus, T. E. and Sikkema, P. H. 2012. Biologically effective rate of saflufenacil/dimethenamid- in soybean (Glycine max). Can. J. Plant Sci. 92: 517–531. A total of five field studies were conducted over a 2-yr period (2009, 2010) at three Ontario locations to determine the biologically effective rate of saflufenacil/dimethenamid-p applied preemergence (PRE) for the control of annual weeds in soybean. The rate of saflufenacil/dimethenamid-p required for the control of annual weeds was influenced by environmental conditions. With adequate moisture and above-average temperatures in 2010, between 224 and 374 g a.i. ha^-1 of saflufenacil/dimethenamid-p was required for 80% control of common ragweed, common lamb's quarters, and green foxtail 4 wk after treatment (WAT). In contrast, below-average temperatures and excessive moisture in 2009 resulted in higher rates of saflufenacil/dimethenamid-p being necessary for the same level of weed control. Pigweed species were least affected by environmental conditions after application at 4 WAT with only 245 g a.i. ha^-1 required for 80% control in both years. By 11 WAT, 320 g a.i. ha^-1 or less of saflufenacil/dimethenamid-p was required to achieve 80% control of these species in 2010, while 845 g a.i. ha^-1 or more was needed in 2009 for equivalent control. The potential of saflufenacil/dimethenamid-p as a set-up treatment prior to a postemergence (POST) glyphosate application was also examined. Excellent full season control of all weed species was achieved with saflufenacil/dimethenamid-p applied PRE followed by glyphosate POST. However, there was no difference in yield when saflufenacil/dimethenamid-p was followed by glyphosate POST compared with a single glyphosate POST application.

Vink, J. P., Soltani, N., Robinson, D. E., Tardif, F. J., Lawton, M. B. and Sikkema, P. H. 2012. Occurrence and distribution of glyphosate-resistant giant ragweed (Ambrosia trifidaL.) in southwestern Ontario. Can. J. Plant Sci. 92: 533–539. Giant ragweed is the first confirmed glyphosate-resistant (GR) weed in Canada. A survey was conducted to document the distribution of GR giant ragweed in southwestern Ontario. Giant ragweed seed was collected from 102 sites in Essex (70), Chatham-Kent (21), Lambton (10) and Waterloo counties (1) during the autumn of 2009 and 2010 prior to soybean harvest. Plants were grown in a growth room, sprayed with glyphosate at 1800 g a.e. ha^-1 and classified as resistant or susceptible. GR giant ragweed has been confirmed at 47 new locations in three counties (Essex, Chatham-Kent and Lambton). The results from this survey indicate that GR giant ragweed biotypes occur across a greater area in southwestern Ontario than originally thought. This survey provides an important baseline for future surveys in the province.

Goyette, B., Vigneault, C., Charles, M. T. and Raghavan, V. G. S. 2012. Effect of hyperbaric treatments on the quality attributes of tomato. Can. J. Plant Sci. 92: 541–551. An experimental hyperbaric system was conceptualized, designed and built to explore the effect of hyperbaric treatment on the quality attributes of tomato. Tomato fruits at the early breaker stage were subjected to hyperbaric pressures of 1, 3, 5, 7 or 9 atm_abs for different durations (5, 10 or 15 d) at 13°C. The effect of hyperbaric treatment on postharvest quality of tomato fruit was evaluated with an emphasis on weight loss, firmness, color, titratable acidity (TA) and total soluble solids (TSS). Hyperbaric treated tomato fruit ripened more slowly and were characterized by lower respiration rate than fruits kept under ambient conditions. Significant differences in weight loss, color, lycopene concentration and firmness were found between hyperbaric treated and control tomato fruit. No significant difference was found in the sugar/acid ratio (TSS/TA).

Viana, J. M. S., Faria, V. R., Fonseca e Silva, F. and Vilela de Resende, M. D. 2012. Combined selection of progeny in crop breeding using best linear unbiased prediction. Can. J. Plant Sci. 92: 553–562. Combined selection is an important strategy in crop breeding. As the classical index does not consider pedigree information, the objective of this study was to evaluate the efficiency of the best linear unbiased prediction (BLUP) methodology for combined selection of progeny. We analyzed expansion volume (EV) and grain yield of parents and inbred and non-inbred progeny from the popcorn population Viçosa. The BLUP analyses, single-trait and of the same character measured in parents and progeny (combined parent-family) were performed using the ASReml software. Because the experiments were balanced, the estimates of the additive variance from the BLUP and least squares analyses were generally equivalent. The accuracies of the BLUP analyses do not clearly establish the superior technique. The accuracy of the classical index tended to be higher than that obtained from BLUP analyses. There was equivalence between BLUP and least squares analyses relative to half-sib and inbred progeny selection, and superiority of the combined parent-family BLUP index for full-sib selection. The BLUP analyses also differed from the least squares analysis on the coincidence of selected parents. The populations obtained by selection based on BLUP of breeding values presented a lower effective size.

Hangs, R. D., Schoenau, J. J., Van Rees, K. C. J. and Knight, J. D. 2012. The effect of irrigation on nitrogen uptake and use efficiency of two willow (Salixspp.) biomass energy varieties. Can. J. Plant Sci. 92: 563–575. Nitrogen (N) fertilizers historically have been applied to support increased productivity of purpose-grown willow (Salix spp.) biomass energy plantations. However, a frequently observed lack of willow growth response to added fertilizer N is often attributed to poor fertilizer use efficiency. The objective of this study was to determine the effect of irrigation on the recovery of broadcast ¹⁵N-labelled fertilizer, applied during the final year of a 3-yr rotation, by two willow varieties. A split-split-plot experiment was established on a fertile heavy clay soil in Saskatoon, SK, Canada, which consisted of two willow varieties (Charlie and SV1), three irrigation treatments (no irrigation, 75%, and 100% field capacity), and two fertilization treatments (1× and 2× the recommended fertilizer rate of 100:30:80:20 N:P:K:S; kg ha^-1). Irrigation increased fertilizer N uptake by Charlie, but had no effect on the amount taken up by SV1, which was attributed to greater N use efficiency of SV1 compared with Charlie when irrigated. Eighty-two percent of the applied fertilizer N was accounted for in the following sinks: 43% in the soil (0–60 cm), 31% in the willow tissues (i.e., stems, leaves, stump, and roots), 7% in the LFH layer, and <1% in the non-crop vegetation; the balance (approximately 18%) was presumed lost primarily through denitrification from the poorly drained soil, but possibly some may have leached below the root zone as well. Although the willow varieties accessed only a portion of the applied fertilizer N during the year of application, the majority of the residual fertilizer N was conserved within the production system and, therefore, remained available for willow uptake in subsequent years.

Turkington, T. K., O'Donovan, J. T., Edney, M. J., Juskiw, P. E., McKenzie, R. H., Harker, K. N., Clayton, G. W., Xi, K., Lafond, G. P., Irvine, R. B., Brandt, S., Johnson, E. N., May, W. E. and Smith, E. 2012. Effect of crop residue, nitrogen rate and fungicide application on malting barley productivity, quality, and foliar disease severity. Can. J. Plant Sci. 92: 577–588. The productivity and quality of the malting barley cultivar AC Metcalfe and leaf disease severity were evaluated under three residue types [barley (Hordeum vulgare L.), canola (Brassica napus L.), field pea (Pisum sativum L.)], two nitrogen (N) fertilizer rates (50 or 100% of soil test recommendation for N), and two fungicide treatments (no fungicide or fungicide applied) at seven sites across western Canada from 2006 to 2009. Residue type had a significant effect on leaf disease severity, which was increased when barley was the previous crop compared with canola and field peas. In general, emergence, head counts, grain yield, kernel weight, test weight, kernel plumpness were lowest for barley grown on barley residue compared with canola and field pea residue. Fungicide application reduced leaf disease severity and increased yield, kernel weight, test weight, and kernel plumpness, while decreasing dockage and thins. However, the magnitude of the impact of fungicide on one or more of these parameters was lower compared with planting barley on field pea or canola residue. Overall, increasing the N rate from 50 to 100% had no effect on leaf disease levels and only increased yields slightly compared with not planting barley on barley residue. However, the 100% rate of N did significantly increase grain protein levels. In contrast, planting barley on field pea residue did not result in a consistent increase in grain protein.

Smith, T. H., Michaels, T. E., Navabi, A. and Pauls, K. P. 2012. OAC Inferno common bean. Can. J. Plant Sci. 92: 589–592. OAC Inferno (CFIA registration no. 7020) is dark red kidney bean (Phaseolus vulgaris L.) cultivar with a determinate bushy growth habit, mid to full season maturity and good yield potential. Seed has acceptable cooking and canning quality.