Munger, H., Vanasse, A., Rioux, S. and Légère, A. 2014. Bread wheat performance, fusarium head blight incidence and weed infestation response to low-input conservation tillage systems in eastern Canada. Can. J. Plant Sci. 94: 193-201. Bread wheat performance, the incidence of diseases like fusarium head blight (FHB) and weed infestations may be affected by low-input systems and conservation tillage practices. This 2-yr study assessed the effects of three 24-yr-old tillage treatments (MP: moldboard plow; CP: chisel plow; NT: no-till) and two cropping systems (high-input: herbicide and mineral fertilizer; low-input: mechanical weed control and organic fertilizer) on wheat productivity, deoxynivalenol (DON) content, Fusarium graminearum inoculum production, and weed infestation in hard red spring wheat. In 2009, low-input CP and NT yields were 13 and 31% lower, respectively, than low-input MP yield, which was comparable with all of the high-input treatment yields. In 2010, yields were 23% lower in CP and NT compared with MP, and 32% lower in low-input than in high-input systems. Optimum wheat yield in low-input systems appeared conditional to adequate weed control, which was achieved with MP and CP tillage. Protein content, test weight, and 1000-kernel weight were higher in the high-input system than in the low-input system, except for test weight in 2009. DON content was not affected by tillage in either year, and was lower in low-input system than in high-input system in 2009. Fusarium graminearum inoculum measured in 2009 was similar across tillage treatments in the high-input system, whereas in the low-input system, the inoculum was lower in NT than in MP. In 2010, DON content was not affected by any treatment. Hot and dry conditions were not conducive to pathogen development, and may explain the low level of DON and the lack of treatment effect.

Akter, Z., Pageni, B. B., Lupwayi, N. Z. and Balasubramanian, P. M. 2014. Biological nitrogen fixation andnifH gene expression in dry beans (Phaseolus vulgarisL.). Can. J. Plant Sci. 94: 203-212. Dry bean (Phaseolus vulgaris L.) is one of the least efficient nitrogen (N₂) fixers among legumes (approximately 30 to 50 kg N ha^-1). To identify efficient N₂ fixers, 22 dry bean genotypes were screened for symbiotic N₂-fixation in potted low-N soil in the greenhouse under four treatments: (1) uninoculated, (2) inoculated with commercial Rhizobium leguminosarum bv. phaseoli inoculant Nitrastik-D^®, (3) inoculated with commercial Rhizobium inoculant Nodulator^®, and (4) fertilizer N added. Expression of nitrogenase reductase (nifH) gene in selected uninoculated genotypes (nodulated by indigenous rhizobia) was quantified by reverse transcription polymerase chain reaction (RT-PCR) to know if expression of this gene was an indicator of N₂-fixation. Nitrogen fixation potential varied among the genotypes and between the rhizobia inoculants. Genotypes differed in shoot (5.17 to 8.39 g plant^-1) and root (1.71 to 6.44 g plant^-1) dry weights, nodule number (0 to 155 nodules plant^-1) and mass (0.055 to 0.250 mg plant^-1), and N₂-fixed (0 to 129 mg N plant^-1). Genotypes GH-196, FR 266 and AC Redbond fixed the most N₂ (60 to 112 mg N plant^-1) with either rhizobial inoculant, and Viva fixed the highest amount (129 mg N plant^-1) when inoculated with Nitrastik-D. In contrast, AC Black Diamond, Island, Winchester, AC Polaris, LEF 2RB and SEA 5 had low N₂-fixing potential (3 to 23 mg N plant^-1) in inoculated treatments. The qRT-PCR analysis indicated that nifH gene expression was 5 fold higher in GH-196 compared to the non-nodulating mutant R99, which further confirmed the high N₂-fixation capacity of GH-196. After confirmation in the field, dry bean genotypes with improved N₂-fixation potential identified in this study may be used as parents in breeding programs in the development of future cultivars. The nifH gene expression may be used as a rapid test to select dry beans with high N₂-fixation potential.

Jing, Q., Bélanger, G., Qian, B. and Baron, V. 2014. Timothy yield and nutritive value with a three-harvest system under the projected future climate in Canada. Can. J. Plant Sci. 94: 213-222. Timothy (Phleum pratense L.) is harvested twice annually in Canada but with projected climate change, an additional harvest may be possible. Our objective was to evaluate the impact on timothy dry matter (DM) yield and key nutritive value attributes of shifting from a two- to a three-harvest system under projected future climate conditions at 10 sites across Canada. Future climate scenarios were generated with a stochastic weather generator (AAFC-WG) using two global climate models under the forcing of two Intergovernmental Panel on Climate Change emission scenarios and, then, used by the CATIMO (Canadian Timothy Model) grass model to simulate DM yield and key nutritive value attributes. Under future climate scenarios (2040-2069), the additional harvest and the resulting three-harvest system are expected to increase annual DM yield ( 0.46 to 2.47 Mg DM ha^-1) compared with a two-harvest system across Canada but the yield increment will on average be greater in eastern Canada (1.88 Mg DM ha^-1) and Agassiz (2.02 Mg DM ha^-1) than in the prairie provinces of Canada (0.84 Mg DM ha^-1). The DM yield of the first harvest in a three-harvest system is expected to be less than in the two-harvest system, while that of the second harvest would be greater. Decreases in average neutral detergent fibre (NDF) concentration (-19 g kg^-1 DM) and digestibility (dNDF, -5 g kg^-1 NDF) are also expected with the three-harvest system under future conditions. Our results indicate that timothy will take advantage of projected climate change, through taking a third harvest, thereby increasing annual DM production.

Hubbard, M., Germida, J. J. and Vujanovic, V. 2014. Fungal endophyte colonization coincides with altered DNA methylation in drought-stressed wheat seedlings. Can. J. Plant Sci. 94: 223-234. Drought stress is one of the greatest limiting factors to Canadian agricultural production. The endophytic fungus SMCD 2206 improves wheat tolerance for drought. However, the mechanism(s) by which this mycobiont interacts with its host are not known. Methyl-sensitive amplified polymorphism (MSAP) was used to test the hypothesis that the endophyte colonization is associated with epigenetic modifications in drought-stressed wheat. Such epigenetic changes might be linked to elevated plant drought resistance. The DNA methylation patterns observed in drought-stressed wheat seedlings co-cultured with SMCD 2206 resembled those of unstressed controls (with or without the endophyte) much more closely than those of endophyte-free, drought-stressed plants. Consistent with the documented roles of transposable elements in plant epigenetics, DNA sequences isolated from some of the most prominent polymorphic MSAP bands were similar to a CACTA type transposon and two retrotransposons of Gypsy and Copia types. Another polymorphic band was similar to a wheat cytochrome p450 expressed sequence tag, suggesting that inoculation may be linked to altered plant responses to oxidative stress in drought conditions. These findings shed new light on the mechanisms involved in plant-endophyte associations, showing that SMCD 2206 colonization of wheat coincides with epigenetic differences in the plant host.

Zhou, D., Liu, R. and Xiong, S. 2014. Analysis and integration of microarray data of Arabidopsis mutants. Can. J. Plant Sci. 94: 235-243. Nowadays, high-throughput microarray data make it possible to study biological data on a large scale. It has successfully been applied to the gene function prediction in yeast, hypersensitive response in response to pathogen and human cancer. However, within the microarray data, there exists lots of unknown information which is worth mining. Based on mutants' signature genes of Arabidopsis thaliana, we constructed a reference matrix including 267 pairs of subsets of differential reference profiles. We analyzed our data through expression profiles and connectivity map. Two notable results were detected by comparing every mutant in the matrix. Above all, the data mining procedure confirmed the biological relations not only between different stresses and glucose metabolism, but also stresses and MAPK signaling pathway among HSP90, PGM, VTE1, AXR4, SFR6, and SFR2 mutants. In addition, sfr6 might be involved in light cycle regulations, in accordance with the results of the overlap analysis.

Qi, Z., Han, X., Hou, M., Xin, D., Wang, Z., Zhu, R., Hu, Z., Jiang, H., Li, C., Liu, C., Hu, G. and Chen, Q. 2014. QTL analysis of soybean oil content under 17 environments. Can. J. Plant Sci. 94: 245-261. Soybean oil content is a key trait driver of successful soybean quality. Due to its complex nature, less stable quantitative trait loci (QTL) are known. The goal of this study was to identify important and stable QTL affecting soybean oil content using recombination inbred lines (RILs) derived from a cross between Charleston and Dongnong594. The plant materials were planted in three environments across 9 yr in China. The genetic effects were then partitioned into additive main effects (A), epistatic main effects (AA) and their environment interaction effects (AE and AAE) by using composite interval mapping, multiple interval mapping and composite interval mapping in a mixed linear model. Fifty-six QTL were identified on 15 of 20 soybean chromosomes excluding LG C1, D2, E, M and O by composite interval mapping and multiple interval mapping methods. Seven oil content QTL detected on LG A1, 1 on LG A2, 5 on LG B1, 4 on LG B2, 8 on LG C2, 11 on LG D1a, 2 on LG D1b, 4 on LG F, 5 on LG G, 2 on LG H, 1 on LG I, 1 on LG J, 1 on LG K, 2 on LG L and 2 on LG N. Eight QTL showed a good stability across 17 environments. The additive main-effect QTL contributed more phenotypic variation than the epistasis and environmental interaction. This indicated that it is feasible to improve soybean oil content by marker-assisted selection.

Shi, H., Wang, Y., Li, Z., Zhang, D., Zhang, Y., Xiang, D., Li, Y. and Zhang, Y. 2014. Pear IAA1 gene encoding an auxin-responsive Aux/IAA protein is involved in fruit development and response to salicylic acid. Can. J. Plant Sci. 94: 263-271. Auxin-responsive Aux/IAA proteins are rapidly auxin-induced, short-lived proteins that act as repressors for the auxin response factor (ARF)-activated gene expression. A gene encoding an Aux/IAA protein and designated PpIAA1 was isolated from pear (Pyrus pyrifolia). Using PCR amplification techniques, the genomic clone corresponding to PpIAA1 was isolated and shown to contain three introns with typical GT/AG boundaries defining the splice junctions. The deduced PpIAA1 protein contains the conserved features of indole-3-acetic acids (IAA): four Aux/IAA conserved domains, Aux/IAA family domain, Aux/IAA-ARF dimerization domain profile, and conserved nuclear localization signal (NLS) motifs. Phylogenetic analyses clearly demonstrated PpIAA1 has the highest homology with grape VvIAA. PpIAA1 was preferentially expressed in fruit, and moderate expression was found in anthers. Relatively low expression signal was detected in other tissues including shoots, leaves, and petals. Moreover, expression of PpIAA1 was developmentally regulated in fruit. Further study demonstrated that PpIAA1 expression in pear fruit was remarkably regulated by salicylic acid and IAA. The data suggest that PpIAA1 might be involved in the interplay between IAA and salicylic acid signaling pathway during the fruit development of pear.

Xu, D., Guo, S. and Liu, M. 2014. Effects of long-term simulated microgravity on tomato seedlings. Can. J. Plant Sci. 94: 273-280. Whether plants can adapt to a long-term microgravity environment is crucial to their reproduction in bioregenerative life-support systems in space. This research investigated the effects of simulated microgravity on Lycopersivon esculentum Mill. (cv. Dwarf Red-bell). Several indicators, namely germination ratio, percentage of cell membrane damage, malondialdehyde content (MDA), superoxide anion () content, and mininucleolus, were observed 10, 20, 30, and 40 d after planting (DAP). Simulated microgravity [random positioning machine (RPM) treatment] barely had any effect on germination ratio, but it increased MDA, an index indicating membrane lipid peroxidation. Random positioning machine-treated samples had significantly higher content until 16 DAP, but these differences ceased after 21 DAP. Simulated microgravity damaged cell membranes, and the damage severity was positively related to the duration of the simulated microgravity treatment. Mininucleoli were more common in RPM-treated root tips than in the 1×g ones. In conclusion, simulated microgravity seriously disturbed tomato seedling growth by damaging cell membrane integrity, causing the accumulation of hazardous substances, and affecting the cell nucleus structure.

Sas-Paszt, L., Pruski, K., Zurawicz, E., Sumorok, B., Derkowska, E. and Gluszek, S. 2014. The effect of organic mulches and mycorrhizal substrate on growth, yield and quality of Gold Milenium apples on M.9 rootstock. Can. J. Plant Sci. 94: 281-291. A 3-yr study was conducted to evaluate the effects of organic mulches and mycorrhizal substrate on growth and yield of apple cv. Gold Milenium grown on M.9 rootstock. Straw (rye), pine bark, conifer tree sawdust, compost (plant debris), cow manure, peat moss substrate (commercial), and mycorrhiza substrate (Mykoflor^®, containing mycorrhizal fungi: Glomus intraradices, G. mosseae, G. etunicatum) were applied in spring of each year. All the applied treatments did not affect significantly the tree growth. Mulches did not have a positive effect on total soluble solids of the fruit and the number of fruits in different size categories. Only sawdust mulch significantly increased the number of fruit in size diameter class of 7.0-7.5 cm compared with the control. The use of mulches affected the concentration of macro- and microelements in leaves, particularly Cu, Fe, Mn and Zn. Mulches positively affected the pH and organic matter content of soil. The best results were observed with the use of the compost, cow manure and the mycorrhizal substrate, where the concentrations of P, K and Mg, most of microelements and soil organic matter were elevated.

Wang, R., Huang, H., Lin, Y., Chen, Q., Liang, Z. and Wu, T. 2014. Genetic and gene expression analysis of dm1, a dwarf mutant from Cucurbita maxima Duch. ex Lam, based on the AFLP method. Can. J. Plant Sci. 94: 293-302. dm1, a dwarf mutant from Cucurbita maxima (Duch. ex Lam) by natural mutation, showed distinct dwarf phenotypes such as shorter vines and fewer and shorter internodes. Genetic analysis indicated that the dm1 mutation was recessive, and the dwarfing character was controlled by a single locus. DNA-AFLP analysis showed that a fragment (MCAG/ETT) was linked with the dwarfing character of dm1 and that the fragment contained 152 base pairs (bp). It was investigated in F₂ populations of dm1 and vine plants, and the genetic distance between the MCAG/ETT fragment and dwarf gene in dm1 was 11.2 cM, calculated by JoinMap 3.0 software. In addition, the result of cDNA-AFLP analysis showed that there were 52 differential transcript derived fragments (TDFs) found between dm1 and vine plants. Only four TDFs, A16T12, A16T9, A6T14 and A6T16, were expressed stably and specifically in dm1 plants in subsequent investigation. The four fragments share 71, 79, 87 and 79% nucleic acid sequence similarity with the complete coding sequence of Arabidopsis thaliana histidine kinase 3 (AHK3) mRNA, nucleic acid sequence of Vitis vinifera dihydroflavonol-4-reductase-like (DFRL), nucleic acid sequence of Glycine max histone-lysine N-methyltransferase ATX4-like and nucleic acid sequence of Arabidopsis thaliana histidinol dehydrogenase (HDH), respectively. Bioinformatics analysis indicated that AHK3, DFRL and HDH were respectively related to Cytokinin signaling, indole acetic acid signaling and Ni accumulation, which played important roles in plant growth, so the expression of the four TDFs may contribute to form dwarfism in dm1.

Aladenola, O. and Madramootoo, C. 2014. Response of greenhouse-grown bell pepper (Capsicum annuum L.) to variable irrigation. Can. J. Plant Sci. 94: 303-310. In order to optimize water use in bell pepper production information about the appropriate irrigation water applications and agronomic and physiological response to mild and severe water stress is necessary. Different water applications were tested on yield, quality and water stress threshold of greenhouse-grown bell pepper (Capsicum annuum L.) cultivar Red Knight in 2011 and 2012 on the Macdonald Campus of McGill University, Ste Anne De Bellevue, QC. The study was carried out on a soil substrate in the greenhouse. Irrigation was scheduled with four treatments:120% (T₁), 100% (T₂), 80% (T₃), and 40% (T₄) replenishment of crop evapotranspiration in a completely randomized design. The highest marketable yield, water use efficiency and irrigation water use efficiency were obtained with T₁ in both years_. T₁ received 20% more water than T₂ to produce 23% more marketable yield than T_2. Fruit total soluble solids content was highest in T₄, and smallest in T₁. The mean crop water stress index (CWSI) of the irrigation treatments ranged between 0.08 and 1.18. Leaf stomatal conductance of bell pepper was 75 to 80% lower in T₄ than in T_1. Regression obtained between stomatal conductance and CWSI resulted in a polynomial curve with coefficients of determination of 0.88 and 0.97 in 2011 and 2012, respectively. The result from this study indicate that the yield derived justifies the use of an extra quantity of water. Information from this study will help water regulators to make appropriate decision about water to be allocated for greenhouse production of bell pepper.

Hwang, S. F., Ahmed, H. U., Turnbull, G. D., Gossen, B. D. and Strelkov, S. E. 2014. The effect of seed size, seed treatment, seeding date and depth on Rhizoctonia seedling blight of canola. Can. J. Plant Sci. 94: 311-321. Rhizoctonia solani can have a substantial impact on seedling establishment and productivity of canola (Brassica napus). The effects of seeding date, seeding depth, seed size, and seed treatment on seedling blight of canola were evaluated under greenhouse and field conditions. Early seeding resulted in higher seedling emergence in one trial year and higher seed yield in all trial years relative to a late-seeded treatment. Mid-sized seed (range 0.7-2.0 mm diam.) had greater seedling emergence in R. solani-inoculated growth medium in a greenhouse trial and higher seed yield in one of two field trials compared with smaller seed (<0.7 mm). In the greenhouse study, sowing of large seed resulted in greater plant height and shoot weight compared with sowing of smaller seed. The effect of seeding depth was significant only on shoot dry weight, which increased at a seeding depth of 2.6 cm. Seed treatment with Helix Xtra (thiamethoxam difenconazole metalaxyl fludioxonil), and Prosper FX (clothianidin carboxin trifloxystrobin metalaxyl) resulted in a significant increase in seedling emergence and yield compared with the inoculated control. These results indicate that fungicidal seed treatment can minimize the impact of R. solani on canola.

Eryigit, T., Okut, N., Ekici, K. and Yildirim, B. 2014. Chemical composition and antibacterial activities of Juniperus horizontalis essential oil. Can. J. Plant Sci. 94: 323-327. In recent years, the screening of antibacterial activity has been the subject of much research, and the antibacterial activity of essential oils could be a promising subject for future investigation. In this study, the antibacterial activities of Juniperus horizontalis essential oils and their components were investigated. Essential oils were isolated using the hydro-distillation method and their components were analyzed by gas chromatography-mass spectrometry (GC-MS). The main compounds found in the oil of leaves were linalool (33.76%), P-cymene (23.20%), gamma-terpinene (8.67%), trans-sabinene hydrate (8.59%), thyme camphor (8.49%), carvol (5.08%) and borneol (4.22%). Juniperus horizontalis essential oils were evaluated for antibacterial activity against six bacterial strains using the disc diffusion method. The results indicate that the essential oil of J. horizontalis shows variable and significant antibacterial activities against the six tested bacteria species. The diameters of the inhibition zones formed for bacteria were measured. The lowest inhibition zone was 12 mm (sensitive) against Pseudomonas aeruginosa ATCC 10145 and the highest zone was 32 mm (extremely sensitive) against Enterococcus faecalis ATCC 29212.

Grant, C. A. 2014. Use of NBPT and ammonium thiosulphate as urease inhibitors with varying surface placement of urea and urea ammonium nitrate in production of hard red spring wheat under reduced tillage management. Can. J. Plant Sci. 94: 329-335. Field studies were conducted at two locations over 3 yr to evaluate the effect of surface placement of urea ammonium nitrate (UAN) and urea fertilizers, with and without the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) on straw and grain yield of hard red spring wheat (Triticum aestivum L.) grown under reduced tillage management. Ammonium thiosulphate (ATS) was also evaluated as a urease inhibitor with UAN. Surface sprayed applications of UAN were frequently less effective than dribble-banded UAN applications or broadcast or dribble-banded urea in increasing grain or straw yield of hard red spring wheat. Use of NBPT with the sprayed UAN increased its effectiveness, so that grain and straw yields were similar to those with urea or with surface dribble-banded UAN. Addition of NBPT to broadcast or banded urea did not increase straw or grain yield under the conditions of this study. While there was some indication that use of ATS with UAN may have had a limited effect on fertilizer efficiency, it did not increase final grain yield as compared with dribble-banded or spray UAN applied alone or with NBPT. If surface nitrogen (N) applications are used in reduced tillage systems, spray applications of UAN should be avoided in favour of dribble-band applications, or the use of urea. Alternately, NBPT may be effective in improving the efficacy of spray UAN.

Alam, M. Z., Braun, G., Norrie, J. and Hodges, D. M. 2014. Ascophyllumextract application can promote plant growth and root yield in carrot associated with increased root-zone soil microbial activity. Can. J. Plant Sci. 94: 337-348. Root growth and soil microbial activity were examined in two cultivars of carrot following treatment with Ascophyllum nodosum marine-plant extract. Field experiments were established in grower-managed fields of Maverick and Pronto carrots during 2010 and 2011. Soluble Ascophyllum extract powder (SAEP) was applied weekly, bi-weekly or tri-weekly at rates of 0 (control), 0.25, 0.50, 0.75 or 1.0 g L^-1 over 11 to 13 wk. Results indicate that SAEP treatment increased root yields of Maverick and Pronto by about 20 and 15%, respectively, reduced proportion of smaller roots and improved harvest index (HI). Maximum yield was found at or above 0.50 g L^-1 SAEP for Maverick and at 0.75 g L^-1 for Pronto. Soil microbial colony counts, respiration and metabolic activity increased following SAEP applications, but varied with SAEP rate and application frequency. Using the Biolog microbial analysis system, maximum average well colour development (AWCD), substrate diversity (H), substrate evenness (E), and substrate richness (S) responses to extract treatment generally showed successive increases at 0.50, 0.75 and 1 g L^-1 SAEP at tri-weekly application frequencies. With more frequent applications, rates below 1 g L^-1 led to greater microbial growth, respiration and functional activities. Principal component analysis (PCA) showed a strong relationship between carrot growth, soil microbial populations and activity parameters. These results suggest that seaweed extract application can result in an increase in soil microbial activity associated with increased yield in carrots.

Jia, D.-Y., Dai, X.-L., Men, H.-W. and He, M.-R. 2014. Assessment of winter wheat (Triticum aestivum L.) grown under alternate furrow irrigation in northern China: Grain yield and water use efficiency. Can. J. Plant Sci. 94: 349-359. Increasing water use efficiency (WUE) can improve agricultural production in the north of China, where there is little or no prospect for the expansion of water resources. A field experiment was carried out to investigate the effects of alternate furrow irrigation (AFI) on the physiological response, grain yield, and WUE of winter wheat (Triticum aestivum L.) over two successive growing seasons (2009/2010 and 2010/2011). The irrigation regimes were: W0, non-irrigated; W2, every furrow was irrigated at jointing and anthesis; W3, every furrow was irrigated before wintering and at jointing and grain filling; and AFI, where one of the two neighboring furrows was alternately irrigated before wintering and at grain filling, and every furrow was irrigated during jointing. Our results indicate that the rate of plant transpiration and soil evaporation during grain filling were lower with AFI than when using W3. A reduced biological yield and increased harvest index were achieved under AFI compared with treatment W3. No difference in grain yield was observed between AFI and W3. The photosynthetic WUE, irrigation WUE, and WUE were all higher with AFI than with W3. Therefore, AFI is suggested as an appropriate irrigation schedule that achieves acceptable grain yields and allows for reductions in irrigation water consumption.

DeLong, J., Prange, R., Harrison, P., Nichols, D. and Wright, H. 2014. Determination of optimal harvest boundaries for Honeycrisp™ fruit using a new chlorophyll meter. Can. J. Plant Sci. 94: 361-369. In this study, a new chlorophyll measurement tool [the delta absorbance (DA) meter] was used to develop an optimal harvest maturity model for Honeycrisp™ fruit. Apples from nine commercial orchards in the Annapolis Valley, Nova Scotia, Canada, were sampled over 11 consecutive weekly harvests during the 2010, 2011 and 2012 growing seasons. At each harvest, a sample of fruit was measured for its DA (I_AD) values, firmness, titratable acidity (TA),% soluble solids content (SSC), red skin coloration and internal core ethylene. Following approximately 3 mo of storage at 3.5°C, samples were removed and assessed for disorder incidence. The optimal harvest period was identified by aligning all “at harvest” I_AD values, fruit quality measurements and “post-storage” disorder data with the corresponding harvest week. Then, the I_AD values associated with the harvests having high commercial fruit quality and the least collective expression of disorders, delineated the optimal harvest boundaries. As I_AD units declined during fruit maturity, the upper boundary value of 0.59 was deemed “when to begin” harvest, while the lower boundary value of 0.36 was deemed “when to end” harvest for long-term storage. The use of the DA model approach for optimal harvest delineation is potentially applicable to all commercial apple cultivars, but should be developed for each within a distinct growing region.

Martens, G., Lamari, L., Grieger, A., Gulden, R. H. and McCallum, B. 2014. Comparative yield, disease resistance and response to fungicide for forty-five historic Canadian wheat cultivars. Can. J. Plant Sci. 94: 371-381. Forty-five historic Canadian spring wheat cultivars, ranging from Red Fife (1870) to modern cultivars, were compared for yield and disease resistance in field trials from 2007 to 2010. A split-plot design was used to test yield, leaf rust and Fusarium head blight resistance, with or without a fungicide application. Older cultivars were generally lower yielding and more leaf rust susceptible than modern cultivars; this difference was greatest in 2007 and 2010 under heavier leaf rust. Response to fungicide application was highest in 2007 and 2010. In 2008, leaf rust was very low, and fungicide application had a slightly negative effect on yield overall. Cultivars that have good leaf rust resistance, such as Pasqua, AC Minto, and 5600 HR, had a negligible response to fungicide, whereas older, susceptible cultivars had a larger response. Fusarium head blight levels were too low to compare the cultivars. The highest-yielding cultivars in the untreated plots were AC Domain, 5500HR, AC Cora, Roblin and Barrie, whereas AC Cora, AC Domain, McKenzie, Roblin and AC Intrepid were the highest yielding in the fungicide-treated plots. AC Domain, AC Barrie and Roblin were among the most popular wheat cultivars in Manitoba, in terms of seeded area from the early 1990s to 2009.

Pedneault, K., Dorais, M., Léonhart, S., Angers, P. and Gosselin, A. 2014. Time-course accumulation of flavonoids in hydroponically grown Achillea millefolium L. Can. J. Plant. Sci. 94: 383-395. In recent decades, the use of plant-based medicines as health products has increased considerably all over the world. As greenhouse hydroponic culture allows standardized cultural methods to be used, it may be valuable for reducing the risks associated with harvesting medicinal plants from the wild, such as species dissemination, species misidentification, adulteration, and non-hygienic handling, while allowing the production of high yields of clean, standardized biomass year-round. To evaluate the potential of hydroponic culture for medicinal plant production, the present study investigated the accumulation patterns of apigenin, luteolin, apigenin glycosides, and the chlorogenic acid 5-caffeoylquinic acid in the plant organs of A. millefolium at five phenological stages from 35 to 102 d after sowing, and drew a comparison with outdoor-grown plants at 122 d after sowing. The results showed two flavonoid accumulation peaks: one at the early growth stage (35 d after sowing) and one at early flowering (87 d after sowing). At 87 d after sowing, most of the apigenin glycosides were concentrated in the roots (3.80% wt/wt, dry weight basis), whereas free apigenin and luteolin were located mainly in the flower heads (1.25 and 0.86% wt/wt, dry weight basis, respectively). Early flowering was the best harvesting stage for optimal flavonoid production in terms of active compounds per plant and kilograms of plant biomass per cultivated area. At 122 d after sowing (phenological stage 4), the outdoor-grown plants were nine times smaller than the early flowering plants (87 d after sowing) from the hydroponic system and had a root-tissue apigenin glycoside level that was five times lower than that of the hydroponically grown plants. In conclusion, the use of a hydroponic growing system reduced by 29% the time required to reach phenological stage 4, which corresponds to maximum plant bioactive concentration, in comparison with field production. Therefore, hydroponic culture represents an effective alternative to outdoor production and can result in standardized, high-quality medicinal plant biomass with potential flavonoid yields approximating 515 mg per plant.

Yan, X., Zhao, H., Liu, X., Li, Q., Wang, Y., Yuan, C. and Dong, Y. 2014. Phenotypic traits and diversity of different leaf shape accessions of the wild soybean (Glycine soja Sieb. et Zucc.) in China. Can. J. Plant Sci. 94: 397-404. The phenotypic traits and diversity of different leaf shape groups of 6169 wild soybean accessions were investigated. The results included the following conclusions. First, the lanceolate leaf group had the highest genetic diversity. Second, the mean 100-seed weight was highest in the round leaf group (10.1 g); mean maturity time was longest in the eliptical leaf group (142 d); the ovate-round and linear leaf groups had higher mean protein content (45.7-46.1%); and the round leaf group had the highest oil content (16.3%). Finally, frequencies of white flower, high 100-seed weight and other traits in the round leaf group were disproportionately high; in contrast, linear leaf accessions were primarily characterized by purple flower and low 100-seed weight. Based on these results, we inferred that the lanceolate and linear leaves accessions tended to be wild types, while the round leaf group represented more recently evolved accessions. In addition, the accessions with eliptical, ovate-round and other leaves belonged to the intermediate evolutionary types. Our results also suggest that the abundant variation in leaf shape is an important indicator of level of genetic diversity and evolutionary status, which could facilitate the utilization of germplasm evaluation and classification for the wild soybean.

Boersma, J. G., Conner, R. L., Balasubramanian, P. M., Navabi, A., Yu, K. and Hou, A. 2014. Combining resistance to common bacterial blight, anthracnose, and bean common mosaic virus into Manitoba-adapted dry bean (Phaseolus vulgaris L.) cultivars. Can. J. Plant Sci. 94: 405-415. Resistance to common bacterial blight (CBB) is generally absent in dry bean cultivars. In order to transfer CBB resistance into dry bean cultivars grown in Manitoba, crosses were made between CBB-resistant navy bean OAC Rex and susceptible cultivars Black Violet (black bean), AC Pintoba (pinto bean) and Morden003 (an anthracnose-resistant navy bean). The F₁ progeny were back-crossed to the recurrent susceptible parents for four generations and selections were made based on inoculation tests and molecular markers. The BC₄F₃ populations were evaluated in CBB field disease nurseries for 3 yr at Morden, MB, and Harrow, ON. Three of the 114 BC₄F₃ navy bean lines were shown to have improved resistance to both CBB and anthracnose, whereas approximately 50% of the lines exhibited strong resistance to anthracnose. Meanwhile, 11 black bean and 7 pinto bean lines were selected with resistance to CBB and four of the seven pinto beans were also putatively resistant to bean common mosaic virus (BCMV). There was good agreement between the presence of molecular markers and field resistance to CBB and anthracnose. The resistant lines recovered in this research possess desirable yield potential and seed characteristics, and can be used in crossing for future dry bean improvement.

Hassan, H. M., Jiang, Z.-H., Asmussen, C., McDonald, E. and Qin, W. 2014. Antibacterial activity of northern Ontario medicinal plant extracts. Can. J. Plant Sci. 94: 417-424. In the present study, the antibacterial activity (in vitro) of the leaf and/or flower crude extracts of Anaphalis margaritacea (L.) Benth & Hook.f., Grindelia squarrosa (Pursh) Dunal, Apocynum androsaemifolium L., Arctostaphylos uva-ursi (L.) Spreng, Cornus canadensis L. and Xanthium strumarium L. medicinal plants was analyzed through the hole-plate diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays against Escherichia coli, Aeromonas caviae, Paenibacillus alvei, Micrococcus luteus, Mycobacterium avium subsp. avium and Bacillus cereus bacteria. In addition, the time-kill dynamic processes of these extracts against A. caviae, B. cereus, P. alvei, and M. luteus bacteria were also tested. The leaf and flower extracts of Anap. margaritacea and G. squarrosa possess significant antibacterial activity against all the bacteria tested, with inhibition of A. caviae, P. alvei and M. luteus within 1-12 h of incubation at MBC. Particularly, at higher concentrations of the Anap. margaritacea flower crude extract (2-3×MBC), inhibition of A. caviae, B. cereus, P. alvei, and M. luteus bacteria is achieved between 0.5 and 4 h of incubation. In addition, these extracts exhibit high inhibition diameters (majority > 18 mm) and low MIC and/or MBCs (majority=1.25 mg mL^-1). In contrast, the leaf extracts of Arct. uva-ursi, X. strumarium, Apoc. androsaemifolium and C. canadensis plants demonstrate moderate to low activity. These results indicate that extracts from Anap. margaritacea and G. squarrosa could be a source of novel antimicrobial scaffolds, compounds or pharmacophores with implications in the pharmaceutical industry and medicine.

Karamanos, R., Hanson, K. and Stevenson, F. C. 2014. Nitrogen form, time and rate of application, and nitrification inhibitor effects on crop production. Can. J. Plant Sci. 94: 425-432. Nitrogen management options for anhydrous ammonia (NH₃) and urea were compared in a barley-wheat-canola-wheat cropping sequence (2007-2010) at Watrous and Lake Lenore, SK. The treatment design included a factorial arrangement of N fertilizer form (NH₃ versus urea), nitrification inhibitor application, time of N application (mid-September, mid- to late October, and spring) and four N fertilizer rates (0, 40, 80 and 120 kg ha^-1). Anhydrous ammonia applications at 40 kg N ha^-1 in 2008 (fall) and in 2010 (all times of application) resulted in wheat yield reductions relative to the same applications for urea. For wheat years, yield was reduced for both fall versus spring N fertilizer applications, when no nitrification inhibitor was applied and the inclusion of nitrification inhibitor maintained wheat yield at similar levels across all times of N fertilizer applications, regardless of form. Protein concentration was approximately 2 g kg^-1 greater with urea compared with NH₃ at both sites in 2008 and only at Watrous in 2010. Also, early versus late fall N fertilizer applications consistently increased N concentration of grain only for the 40 and/or 80 kg N ha^-1 rates. Effects of nitrification inhibitor on N concentration were not frequent and appeared to be minimal. Urea had greater agronomic efficiency (AE) than NH₃ at the lower N fertilizer rates. The nitrification inhibitor had a positive effect on wheat AE only for early fall N fertilizer applications. It can be concluded that for maximum yields NH₃ or urea will be suitable if applied at rates of 80 kg N ha^-1 and greater. If N fertilizer is applied at 40 kg N ha^-1, especially in fall without inhibitor, urea is better. In terms of protein concentration for wheat, urea seemed to better than NH₃ and fall was better than spring application.

Karamanos, R., Flaten, D. N. and Stevenson, F. C. 2014. Real differences - Lessons from an agronomist's perspective. Can. J. Plant Sci. 94: 433-437. An experiment including a two penny treatment and an untreated check was established to show that implausible differences can be a statistical reality. An individual crop by location analysis showed that two pennies significantly (P<0.05) increased canola yield at one of the 19 locations, nearly (0.05<P<0.18) affected canola yield at one other location. A combined mixed model analysis showed that canola yield significantly increased by a small amount (0.1 t ha^-1) with two pennies, whereas, a similar mixed model that accounted for residual variance heterogeneity showed that two pennies did not affect crop yield. Our results confirmed that the effect of a treatment not expected to cause a meaningful difference can be detected The results also highlight the importance of modeling all sources of variance, designing more efficient experiments, scrutinizing the size of treatment differences, and choosing an appropriate level of significance to ensure that only real differences are detected.

Bergsten, S. J. and Stewart, J. R. 2014. Measurement of the influence of low water availability on the productivity of Agave weberi cultivated under controlled irrigation. Can. J. Plant Sci. 94: 439-444. In recent years, research has focused on determining the potential of Agave to be utilized for bioenergy production due to its ability to grow in arid and marginal lands. However, little is known regarding its productivity under limited water conditions. Most Agave species can tolerate low soil-moisture levels, but it is unclear at what point productivity will be significantly constrained. Using an automated irrigation system under greenhouse conditions, we evaluated the effects of low to high volumetric water content (VWC) levels on biomass accumulation and nutrient uptake of a putative bioenergy crop, Agave weberi. Plants were exposed to four constant VWC levels (0.05, 0.12, 0.19, and 0.26 m³ m^-3). Shoot dry weight of plants in the 0.26 m³ m^-3 treatment was significantly higher than those in the 0.05 m³ m^-3 treatment, but not than those in the intermediate treatments. Both chlorophyll count and nutrient uptake decreased as VWC level decreased. Although plants were fairly productive under moderately dry soil conditions, it would be expected that over time, plants receiving high levels of irrigation would have greater growth than plants in dry soil moisture levels. However, similar yields between the well-watered and moderately dry treatments suggest that A. weberi should be further evaluated as a candidate energy crop in more long-term field trials.

Duguid, S. D., Rashid, K. Y. and Kenaschuk, E. O. 2014. Prairie Thunder flax. Can. J. Plant Sci. 94: 445-449. Prairie Thunder, medium-maturing oilseed flax (Linum usitatissimum L.), was released in 2006 by Agriculture and Agri-Food Canada, Morden Research Station, Morden, Manitoba. Developed from the cross AC Watson/FP1043 made in 1995, Prairie Thunder was evaluated in the Flax Cooperative Trials (2002-2004) before being registered in 2006. Prairie Thunder's desirable combination of improved agronomic traits, seed quality and superior wilt (Fusarium oxysporum Schlecht. f. sp. lini (Bolley) Snyder & Hansen) resistance should make this cultivar useful for producers and the flax industry.

Booker, H. M., Rowland, G. G. and Rashid, K. Y. 2014. CDC Glas oilseed flax. Can. J. Plant Sci. 94: 451-452. CDC Glas, a medium-late maturing oilseed flax (Linum usitatissimum L.) was released in 2012 by the Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan. This cultivar has medium oil content, medium oil quality, medium seed size, good lodging resistance and high seed yield in all the soil zones of the prairies. It is immune to North American races of rust caused by Melampsora lini, moderately resistant to wilt caused by Fusarium oxysporum f. sp. lini and moderately resistant to powdery mildew caused by Oidium lini.

McVetty, P. B. E., Cuthbert, J. L., Marwede, V., Paulmann, W., Sass, O., Duncan, R. W., Fernando, W. G. D., Li, G. and Zelmer, C. D. 2014. HYHEAR 1 hybrid Roundup Ready™ high erucic acid, low glucosinolate summer rape. Can. J. Plant Sci. 94: 453-455. HYHEAR 1 summer rape (Brassica napus L.) is the world's first hybrid Roundup Ready™ high erucic acid, low glucosinolate cultivar. On average, HYHEAR 1 yielded 33% more seed, 23 g kg^-1 more seed oil but 17 g kg ^-1 less meal protein than MillenniUM 03 high erucic acid, low glucosinolate, open pollinated population summer rape. HYHEAR 1 has an erucic acid content of 52.2% in isolated field trials of HEAR lines and is adapted to the southern B. napus growing regions of western Canada.

Yu, K., Woodrow, L. and Poysa, V. 2014. AAC Stern soybean. Can. J. Plant Sci. 94: 457-459. AAC Stern is a high-protein, high-yielding, food-grade soybean cultivar [Glycine max (L.) Merr] with yellow hilum and acceptable processing quality for foreign and domestic tofu and soymilk markets. AAC Stern is adapted to areas of southwest Ontario with 3250 or more crop heat units and has a relative maturity of 2.8 (MG 2.8).

Amankwa, G. A., Mishra, S., Shearer, A. D., Brammall, R. and Van Hooren, D. L. 2014. CTH8 flue-cured tobacco hybrid. Can. J. Plant Sci. 94: 461-463. CTH8 is a new flue-cured tobacco (Nicotiana tabacum L.) hybrid recommended for commercial release in Canada. It has superior grade index compared to the check varieties Delgold and CT157, and its yield potential is intermediate between the two checks.

Choo, T. M., Martin, R. A., Xue, A., MacDonald, D., Scott, P., Rowsell, J., Dion, Y. and Rioux, S. 2014. AAC Mirabel barley. Can. J. Plant Sci. 94: 465-468. AAC Mirabel is a six-row spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada. It has high grain yield and moderate resistance to barley yellow dwarf virus, powdery mildew, leaf rust, and loose smuts. AAC Mirabel performs well across Eastern Canada.

Bett, K. E., Vandenberg, A., Banniza, S., Lu, Q., Barlow, B. and Ife, S. 2014. CDC WM-2 common bean. Can. J. Plant Sci. 94: 469-471. CDC WM-2 is a short-season, slow-darkening, pinto bean cultivar (CFIA Registration #6593) with indeterminate growth habit and tolerance to common bacterial blight and anthracnose races 73 and 105. It was developed using marker-assisted backcrossing and field testing.