Adebayo, O., Bélanger, A. and Khanizadeh, S. 2013. Variable inhibitory activities of essential oils of threeMonardaspecies on the growth ofBotrytis cinerea. Can. J. Plant Sci. 93: 987-995. The antifungal effects of the essential oils of three Monarda species (Monarda didyma L., M. fistulosa L., and M. didyma var. 80-1A L.) were evaluated against Botrytis cinerea Pers.: Fr. The inhibitory effects of the volatile and contact phases of the essential oils were determined on hyphae and spores. The effects of the essential oils on the morphological structures of hyphae were studied under light microscopy. All the three tested essential oils types had inhibitory effects on both mycelia and spores as follows, in descending order of effectiveness: M. didyma > M. didyma var. 80-1A > M. fistulosa. For all essential oils, the volatile phase effects were more toxic on fungal growth than the contact phase effects. All the essential oils in the contact studies achieved complete inhibition of mycelial growth and spore germination at 819.2 µg mL^-1 of ethanol and Tween 20 mixture. In the volatile studies, however, complete mycelial inhibition was achieved with M. didyma and M. didyma var. 80-1A at 0.1 µg mL^-1 air and with M. fistulosa at 0.2 µg mL^-1 air. Spore germination was inhibited at 0.05 µg mL^-1 air with M. didyma and 0.2 µg mL^-1 air with both M. didyma var. 80-1A and M. fistulosa. This study demonstrated that these essential oils are promising potential antifungal agents that could be used in the development of biofungicide alternatives to synthetic fungicides against B. cinerea.

Sinclair, G., Charest, C., Dalpé, Y. and Khanizadeh, S. 2013. Influence of arbuscular mycorrhizal fungi and a root endophyte on the biomass and root morphology of selected strawberry cultivars under salt conditions. Can. J. Plant Sci. 93: 997-999. The influence of four arbuscular mycorrhizal fungi (AMF) (Glomus arenarium, G. caledonium, G. irregulare, and G. mosseae) and a root endophyte species (Piriformospora indica - Sebacinales) was investigated on four “day-neutral” strawberry (Fragaria×ananassa Duch.) cultivars (Albion, Charlotte, Mara des Bois, and Seascape) for their tolerance to salt stress. Fungal symbiosis tended to benefit strawberry plants in their tolerance to salinity, confirming the potential use of mycorrhizal biotechnology in horticulture in arid areas.

Goyali, J. C., Igamberdiev, A. U. and Debnath, S. C. 2013. Morphology, phenolic content and antioxidant capacity of lowbush blueberry (Vaccinium angustifoliumAit.) plants as affected by in vitro and ex vitro propagation methods. Can. J. Plant Sci. 93: 1001-1008. The lowbush blueberry (Vaccinium angustifolium Ait.), a commercially important crop in eastern Canada and the United States of America, is native to North America. It is one of the richest sources of antioxidant compounds and has been reported to be a potential component in reducing the incidence of cancers and cardiovascular diseases. The aim of this study is to evaluate the effect of propagation methods on morphological characters, phenolic content and antioxidant activity. A lowbush blueberry clone, QB 9C, and a cultivar, Fundy, were studied over two growing seasons after being propagated by conventional softwood cutting (SC) and by tissue culture (TC). Significant interactions among genotypes, propagation methods and growing seasons were observed for number of flower buds, total flavonoid (TFC) and proanthocyanidin (PAC) contents and antioxidant capacity. Propagation method interacted significantly with genotypes for the number of stems per plant and total phenolic (TPC) and chlorophyll contents, and with growing season for number of flower buds, TFC and PAC. TC plants produced higher number of stems and branches compared with SC plants. TPC, TFC, PAC, chlorophyll content and antioxidant activity were found in higher levels in the leaves of QB 9C compared with those of Fundy plants. The juvenile characteristics of TC plants which are triggered by growth hormones and readily available nutrients of culture media may be responsible for differences in morphological traits and antioxidant activity.

MacDonald, W. N., Blom, T. J., Tsujita, M. J. and Shelp, B. J. 2013. Review: Improving nitrogen use efficiency of potted chrysanthemum: Strategies and benefits. Can. J. Plant Sci. 93: 1009-1016. Floricultural greenhouse operations can pose significant environmental risk due to the leaching and runoff of nutrients such as . To face this challenge, Ontario growers have adopted recirculating systems, such as the subirrigated “ebb and flow” system, on benches, troughs and concrete floors. Chrysanthemum (Chrysanthemum morifolium Ramat.) is the most commonly grown floricultural greenhouse crop species in the world and the potted type is well adapted to subirrigation. Reduction of N fertilization towards the end of the crop cycle is generally recommended to improve the shelf life of cut and potted plants, but it is uncertain how this practice influences the N status of the plant and the electrical conductivity of the growing medium. In this review, we discuss N use efficiency and strategies for managing the status of plants, and then propose that this knowledge can help to improve the N use efficiency of potted chrysanthemum grown with subirrigation under greenhouse conditions.

Carew, R., Florkowski, W. J. and Zhang, Y. 2013. Review: Industry levy-funded pulse crop research in Canada: Evidence from the prairie provinces. Can. J. Plant Sci. 93: 1017-1028. Since the 1970s the prairies provinces have become a major producer of pulse crops, attributed to diversified cropping systems and the adoption of improved cultivars. This article reviews pulse production trends and research funding for pulse crop research, emphasizing both the contribution of governments and public research institutions/industry arrangements in shaping the growth of the pulse sector. The expansion of pulse production has not been associated with rapid increases in publicly funded research. The study found that industry-/producer-funded research as a share of pulse farm cash receipts has been larger in Saskatchewan and Manitoba than in Alberta. Moreover, the unique consortium arrangement of funding pulse research in Alberta by the provincial government has resulted in larger research intensities than for provincial government funding in Saskatchewan or Manitoba. Furthermore, the intellectual property protection of pulse cultivars since the enactment of the Plant Breeders' Rights Act in 1990 has increased Canadian producers' access to field pea cultivars developed by foreign seed companies.

Hua, W., Zhu, J., Shang, Y., Wang, J., Jia, Q., Lin, F. and Yang, J. 2013. Establishment of a highly efficient regeneration method from the scraped broken embryo of mature barley seed. Can. J. Plant Sci. 93: 1029-1035. An efficient and reproducible plant regeneration system for mature barley would represent a significant innovation for barley tissue culture and genetic transformations to optimize barley crop traits. To address this need, we used scraped broken embryos (SBEs) from dried barley seeds to establish a highly efficient regeneration system. Mature SBEs cultured in an induction medium with 2 mg L^-1 2,4-D offered the best callus formation (92.99% induction efficiency) and no germination. Furthermore, calli arising from SBEs had the highest regeneration frequency (69.72%) in FHG medium with 1 mg L^-1 6-benzylaminopurine. We then compared three different cultivars: Golden Promise, Zaoshu3, and Zhepi8 for callogenesis and regeneration using an established protocol. Zhepi8 had the greatest callus induction (92.78%) and regeneration (68.24%). Our innovative methods for mature barley plant reproduction will contribute to improvements in genetic barley transformation as an alternate regeneration system.

Tullu, A., Bett, K., Banniza, S., Vail, S. and Vandenberg, A. 2013. Widening the genetic base of cultivated lentil through hybridization ofLensculinaris‘Eston’ andL.ervoidesaccession IG 72815. Can. J. Plant Sci. 93: 1037-1047. Lentil (Lensculinaris Medik.) is affected by many stresses and the genetic variation for resistance to some of these stresses is limited in the cultivated germplasm. Introgression of genes from diverse sources for the improvement of disease resistance and agronomic performance is urgently needed. An interspecific recombinant inbred line (RIL) population designated LR-26 was developed from a cross of L. culinaris ‘Eston’ and L. ervoides (Brign.) Grande accession IG 72815. RILs were phenotyped (1) to examine the inheritance of resistance to the more aggressive race 0 of Colletotrichum truncatum (Schwein.) Andus & W.D. Moore, causal agent of anthracnose, for which resistance is lacking in the cultivated species and (2) to study the genetic variation in agronomic traits and their relationships to each other. Greenhouse studies were conducted to screen for resistance to race 0 of C. truncatum and evaluate RILs for variations of agronomic characters. Two recessive genes conferred resistance in L. ervoides accession IG 72815. Traits varied significantly and showed transgressive segregations. Seed yield had a significant and positive relationship with biomass, straw yield, seed weight and harvest index. About 20 lines that performed better than Eston in terms of podding ability, lodging, and stand at maturity can be used in a breeding program. LR-26-180 had an 8% greater seed weight than Eston, suggesting that IG 72815 has alleles contributing positively to seed size. Overall, results show that IG 72815 can be used in breeding programs to improve disease resistance and quantitative traits of lentil.

Barbieri, P. A., Echeverría, H. E., Sainz Rozas, H. R. and Andrade, F. H. 2013. Nitrogen status in maize grown at different row spacings and nitrogen availability. Can. J. Plant Sci. 93: 1049-1058. Improving nitrogen use efficiency (NUE) is imperative to sustainable agriculture. To attain this goal in maize crops (Zea mays L.) there are nitrogen (N) diagnosis methods that enable determination of a crop's nutritional status by analysis of plant parts. Maize planted in narrow rows (NR) can have increased dry matter (DM), grain yield and accumulated N. However, no reports have been found on the effect of NR of N in plant diagnosis methods. An experiment was performed over 3 yr to evaluate NR and N fertilizer rates on the N dilution curve, N concentration in grain and chlorophyll content in maize. Treatments consisted of a factorial combination of row width (70, 52 and 35 cm) and N rate (0 to 180 kg N ha^-1). The N dilution curves adjusted for fertilized or control treatments were similar among row spacing. Nitrogen concentration in grain was correlated with relative yield (RY), and similar critical values for N response were similar between row spacings. Leaf chlorophyll content increased with N and NR; however, green index (GI) and N sufficiency index (NSI) values were not different between row spacing when correlated to RY. These results indicate that response thresholds to N fertilization determined on plant tissue for NR treatments were similar among row spacings. Thus, there is no need to adjust the response thresholds to N application based on row spacing, as NR did not cause any changes in physiological efficiency (PE) due to the determined proportional increases, both in accumulated N in DM and grain yield.

Garrett, R. G., Gawalko, E., Wang, N., Richter, A. and Warkentin, T. D. 2013. Macro-relationships between regional-scale field pea (Pisum sativum) selenium chemistry and environmental factors in western Canada. Can. J. Plant Sci. 93: 1059-1071. A baseline study of cultivar, temporal (2004-2006) and spatial variability in field pea (Pisum sativum) selenium (Se) concentration was undertaken in western Canada based on six common cultivars (295 samples) grown in 35 variety trials. Selenium was determined by atomic absorption spectroscopy following a HNO₃ digestion. Non-significant differences in pea Se concentration occurred due to cultivar and temporal variability. Trial site soil organic C, pH, cation exchange capacity, soil texture estimates, and classifications were recovered from Agriculture and Agri-Food Canada's Canadian Soil Information System database. Twenty-five percent of the pea Se variability was due to soil edaphic factors, particularly organic C and pH, this increased to 39% with inclusion of great soil group classification. The remaining variability was due to growing season weather conditions, with hotter drier summers leading to higher Se concentrations. Naturally Se biofortified pulses are available to be targeted to selenium deficient populations.

Johnson, E. N., Malhi, S. S., Hall, L. M. and Phelps, S. 2013. Effects of nitrogen fertilizer application on seed yield, N uptake, N use efficiency, and seed quality ofBrassica carinata. Can. J. Plant Sci. 93: 1073-1081. Ethiopian mustard (Brassica carinata A. Braun) is a relatively new crop in western Canada and research information on its response to N fertilizer is lacking. Two field experiments (exp. 1 at 3 site-years and exp. 2 at 4 site-years) were conducted from 2008 to 2010 in Saskatchewan and Alberta, Canada, to determine effect of N fertilizer application on Brassica carinata plant density, seed and straw yield, N uptake in seed and straw, N use efficiency (NUE), N fertilizer use efficiency (NFUE) and seed quality. N rates applied were 0 to 160 kg N ha^-1 and 0 to 200 kg N ha^-1 in exps. 1 and 2, respectively. Plant density was not affected by increasing N rate at 5 site-years but declined with high rates of N application at 2 site-years. Seed yield responded to applied N in 6 of 7 site-years, with the non-responsive site having a high total N uptake at the 0 kg N ha^-1 rate (high N_t value). There were no sites where seed yields were maximized with the N rates applied. Response trends of straw yield and N uptake were similar to that of seed yield at the corresponding site-years. NUE and NFUE generally declined as N rate increased. Protein concentration in seed generally increased and oil concentration in seed decreased with increasing N rates. In conclusion, the responses of seed yield, total N uptake, NUE, and NFUE to applied N was similar to those reported in other Brassica species with the exception that a rate was not identified in which Brassica carinata yields were maximized.

Séguin-Swartz, G., Beckie, H. J., Warwick, S. I., Roslinsky, V., Nettleton, J. A., Johnson, E. N. and Falk, K. C. 2013. Pollen-mediated gene flow between glyphosate-resistantBrassica napuscanola andB. junceaandB. carinatamustard crops under large-scale field conditions in Saskatchewan. Can. J. Plant Sci. 93: 1083-1087. A Saskatchewan study examined hybridization between two mustard (Brassica juncea and B. carinata) crops that were either adjacent to a glyphosate-resistant canola (B. napus) crop or separated by a 5-m strip. Overall, field hybridization levels, detected with glyphosate resistance and species-specific AFLP markers, were low: 0.024% and up to 400 m in the adjacent B. juncea field and 0.013% (up to 350 m) in the separated field, and 0.005% (up to 150 m) in the adjacent B. carinata field and 0.002% (up to 65 m) in the separated field. Based on fitness information under controlled conditions, the fertility of hybrid plants is expected to be low.

Chen, S., Zhang, X., Ma, X. and Huang, L. 2013. Assessment of genetic diversity and differentiation ofElymus nutansindigenous to Qinghai-Tibet Plateau using simple sequence repeats markers. Can. J. Plant Sci. 93: 1089-1096. Elymus nutans Griseb., an important alpine forage grass, is widely distributed in the Qinghai-Tibet Plateau. A total of 50 E. nutans accessions from the eastern Qinghai-Tibet Plateau were analyzed using simple sequence repeats (SSR) markers from wheat and Elymus species. Our results show that a total of 144 reliable bands were generated, of which 132 (91.38%) were found to be polymorphic. Nei-Li's genetic similarity coefficients ranged from 0.515 to 0.870 with an average of 0.719, which shows a high level of genetic diversity and a broad genetic base among accessions. There was a low correlation between genetic distance and geographical distance (r=0.121, P=0.088) in the region, which is consistent with the unweighted pair group method with arithmetic average cluster analysis of accessions. The mountain ridges and river valleys in the eastern Qinghai-Tibet region could serve as genetic barriers for pollinator movement and seed dispersal. The rule of the most genetic diversity at medium altitude of E. nutans in the Qinghai-Tibet Plateau was also validated in the study. The implications of these results for the conservation of E. nutans are discussed.

Liu, Y., Fu, Y.-B. and Coulman, B. E. 2013. Evaluating genetic variation and relationships amongPuccinellia nuttallianapopulations using amplified fragment length polymorphism markers. Can. J. Plant Sci. 93: 1097-1104. Nuttall's salt-meadow, or alkali grass [Puccinellia nuttalliana (Shultes) Hitchc.], is a native grass species in North America, well known for its salt tolerance. Little information is available about the genetic diversity of natural populations of this species. Amplified fragment length polymorphism (AFLP) markers were used to examine the inter-population relationships and to compare variances within and among 23 populations collected from the Canadian Great Plains. Five AFLP primer pairs were employed to screen 15 genotypes (five sets of three half-sib plants) from each population, and 185 polymorphic AFLP bands were scored for each sample. The frequencies of these scored bands ranged from 0.02 to 0.99 with a mean of 0.60. The analysis of molecular variance revealed more than 96% of the total AFLP variation resided within populations. Populations were not highly differentiated with only 4% of the total AFLP variation residing among populations. A Mantel test revealed a significant but low correlation between genetic and geographic distances (r=0.29, P=0.024). Implications for P. nuttalliana conservation, germplasm sampling, and cultivar development are discussed.

Biligetu, B., Schellenberg, M. P. and Fu, Y.B. 2013. Genetic diversity of side-oats grama [Bouteloua curtipendula (Michx.) Torr.] populations as revealed by amplified fragment length polymorphism markers. Can. J. Plant Sci. 93: 1105-1114. Side-oats grama [Bouteloua curtipendula (Michx.) Torr.] is a warm-season grass widely distributed in North America and is considered as an important grass for reclamation and summer forage production in drier regions. This study assessed genetic diversity of nine wild populations of side-oats grama grass, their corresponding balanced multiple-site composite (BMSC), and a population selected for forage type (FT), using the amplified fragment length polymorphism (AFLP) technique. Five AFLP primer pairs were employed to genotype 157 plants, and 312 polymorphic AFLP bands were detected. The frequencies of AFLP bands ranged from 0.01 to 0.99, and averaged 0.39. The AFLP analysis revealed 6% of the total AFLP variation present among the nine wild populations and 94% of variation within populations. The Minto population had the largest within-population diversity, while the FT population the lowest based on AFLP band richness and polymorphic loci. The BMSC population displayed significant genetic differentiation from the wild populations, but still captured substantial genetic diversity. Bayesian cluster analysis using BAPS and STRUCTURE programs revealed three and four optimal clusters of populations that explained 9.8 and 9.5% of the total AFLP variation, respectively. A genetic clustering of individual plants displayed no clear genetic separations among wild, FT, and BMSC populations, but the FT population showed some level of genetic shift, indicating the initial impact of artificial selection. These findings are significant for our understanding of the genetic diversity of side-oats grama. Large genetic variation present within populations provides a potential for further genetic enhancement.

Boersma, J. G., Conner, R. L., Balasubramanian, P. M., Yu, K. and Hou, A. 2013. Marker-assisted dissection of anthracnose resistance in the dry bean cultivar Morden003. Can. J. Plant Sci. 93: 1115-1123. The dry bean cultivar Morden003 is resistant to anthracnose races 73 and 105, the two most prevalent races in western Canada. Previous studies found that Morden003 carried markers OF10_530r, SCAreoli and SAS13 that are linked to the Co-1, Co-2 and Co-4 resistance genes on chromosomes Pv01, Pv11 and Pv08, respectively. Morden003 had a reported resistance spectrum similar to three other cultivars that carry the Co-1⁵ resistance gene. Using F₂ and F_2:3 populations from the reciprocal crosses of Morden003/OAC Rex, we mapped two race-specific resistance gene loci. An examination of known anthracnose resistance and other core markers showed no evidence of resistance being associated with the Co-1, Co-2, or Co-4 loci. Instead, the resistance genes were co-located in the vicinity of the Co-3 locus on Pv04. They were 2 cM apart and flanked by markers SAH18₁₁₀₀ and BM161. The map generated in this research also showed strong linkage of the anthracnose resistance loci to markers SW12, PVctt001 and SF10, which were associated with the Co-3 and Co-10 loci by previous researchers. A weak, distant linkage of marker SB12 to the Co-3 locus was also detected.

Pageni, B. B., Lupwayi, N. Z., Larney, F. J., Kawchuk, L. M. and Gan, Y. 2013. Populations, diversity and identities of bacterial endophytes in potato (Solanum tuberosumL.) cropping systems. Can. J. Plant Sci. 93: 1125-1142. Most plants host endophytic bacteria, but their identities and functions are usually unknown. Bacterial endophytes associated with potato grown after dry bean (Phaseolus vulgaris L.) or wheat (Triticum aestivum L.) were isolated, quantified and identified in a field study that compared crop rotations (3 to 6 yr in length) and soil management (CONV, conventional; CONS, conservation) for dry bean, potato, sugar beet (Beta vulgaris L.) and spring wheat. Populations of culturable endophytes ranged from 2.83×10³ to 7.65×10³ colony-forming units g^-1 of root dry matter. The populations and diversity of the endophytes were greater with CONS than CONV soil management, and tended to be greater in longer than shorter rotations. The community structures of the endophytes were different between CONV and CONS soil management. A terminal-restriction fragment length polymorphism assay targeting the 16S rRNA gene, and its sequencing, showed that CONS management systems contained more Proteobacteria than CONV management systems, and vice-versa for Acidobacteria. Bacteriodetes were found only in long CONS rotations. This phylogenetic characterization of potato endophytes is important for further studies on their effects on the host plants.

Green, R. C. and Low, N. H. 2013. Physicochemical composition of buffaloberry (Shepherdia argentea), chokecherry (Prunus virginiana) and sea buckthorn (Hippophae rhamnoides) fruit harvested in Saskatchewan, Canada. Can. J. Plant Sci. 93: 1143-1153. There is increasing interest in the commercialization of native fruits for utilization as foods and medicinal extracts. This study was undertaken to determine the physicochemical properties of buffaloberry (Shepherdia argentea), chokecherry (Prunus virginiana) and sea buckthorn (Hippophae rhamnoides) fruit grown in Saskatchewan. The physicochemical analyses of samples of each of these fruits included carbohydrate content, CIELAB color values, organic acid composition, pH, percent seed weight, phenolic compound content, soluble solids content, total titratable acidity (TTA) and proximate composition (ash, fibre, lipid, moisture and protein). Buffaloberry was found to contain high TTA and was especially high in ascorbic acid at 209±37 mg 100 g^-1 fruit, fresh weight basis. Chokecherry contained high levels of anthocyanin at 237±41 mg 100 g^-1 fruit, fresh weight basis. The results of this study suggest all of these native fruits possess compounds important to the human diet.

McIsaac, G., Sanderson, K. R., Peters, R. D., Garbary, D. J. and Fillmore, S. A. E. 2013. Impact of commercial foliage trimming on disease suppression and yield of processing carrots in Nova Scotia, Canada. Can. J. Plant Sci. 93: 1155-1163. Carrot side-trimming opens the carrot canopy, permitting greater sunlight penetration and airflow. This reduces moisture build-up and creates unfavorable conditions for the development of common carrot pathogens such as Sclerotinia sclerotiorum (Lib.) de Bary. This study was carried out during the 2008 and 2009 growing seasons and was the first to examine the effects of foliage trimming on disease development in the processing carrot production region of Nova Scotia, Canada. Research focused on the effects of foliage trimming on disease suppression and yield using a commercial-sized trimmer in processing slicer carrots over consecutive growing seasons. This study was also the first to look at the effect of trimming on the suppression of Alternaria dauci (J.G. Kühn) J.W. Groves & Skolko and Cercospora carotae (Pass.), two economically important carrot pathogens causing leaf blight diseases in this region of Canada. Plots were established in commercial fields throughout Colchester County, Nova Scotia. Each field had a trimmed and an untrimmed section. All plots were assessed for disease presence at the time of trimming and again at harvest. Foliage trimming was found to have no significant (P=0.05) effect on biological and marketable yield and generated anecdotal reports of ease of crop maintenance and harvest. The severity of diseases caused by Alternaria, Cercospora and Sclerotinia varied among cultivars and significant cultivar×trimming interactions were noted in some cases. Foliage trimming is becoming standard practice in the carrot industry as several commercial carrot producers in North America have adapted the technology to suit their production needs after the prototype foliage trimmer was designed, built, and demonstrated by researchers at Agriculture and Agri-Food Canada, Charlottetown, Prince Edward Island.

Taskin, H., Yücel, N. K., Baktemur, G., Çömlekçioglu, S. and Büyükalaca, S. 2013. Effects of different genotypes and gamma ray doses on haploidization with irradiated pollen technique in watermelon (Citrullus lanatusL.). Can. J. Plant Sci. 93: 1165-1168. Two watermelon genotypes, one commercial watermelon variety (Ustun F1) and five different doses of gamma rays coming from Co⁶⁰ were tested to develop useful haploidization procedures in watermelon. For this purpose, male flowers collected a day before anthesis were irradiated with 50, 150, 200, 275 and 300 Gy doses of gamma rays, and female flowers were pollinated with irradiated pollen the next day. Seeds extracted from fruits harvested 25 d later were opened individually in a laminar flow hood. Embryos obtained via embryo rescue technique were placed in glass tubes containing CP medium with 30 g L^-1 sucrose, 8 g L^-1 agar, 0.08 mg L^-1 B12, and 0.02 mg L^-1 IAA. Sixty haploid embryos were obtained from 43 watermelon fruits in this study. Genotype 1 was found to be the most successful genotype with 3.57 haploid embryos per 100 seeds. Among tested irradiation doses, 275 Gy was better than other doses, with 5.26 haploid embryos per 100 seeds. Considered together with irradiation dose and genotypes, the maximum number of haploid embryos was obtained from Genotype 1 pollinated with 275 Gy irradiation dose, with 6.25 haploid embryos per 100 seeds.

Beres, B. L., Cárcamo, H. A., Byers, J. R., Clarke, F. R., Ruan, Y., Pozniak, C. J., Basu, S. K. and DePauw, R. M. 2013. Host plant interactions between wheat germplasm source and wheat stem sawflyCephus cinctusNorton (Hymenoptera: Cephidae). II. Other germplasm. Can. J. Plant Sci. 93: 1169-1177. The wheat stem sawfly (WSS) Cephus cinctus Norton (Hymenoptera: Cephidae) is an economically destructive insect pest of wheat in the northern Great Plains. Solid stem cultivar selection is one critical component to the integrated management of WSS. A significant resurgence of WSS in the southern prairies of Canada caused substantial economic losses from 1999 through 2007, which was compounded by the low adoption rate of solid-stem cultivars. A study was conducted from 2003 to 2005 in southern Alberta and Saskatchewan, Canada: (1) to characterize resistance levels in solid-stem germplasm derived from S615 and alternate genetic backgrounds, and (2) to determine the impact of host plant tolerance on WSS population dynamics. The tetraploid cultivar Golden Ball and its hexaploid derivative G9608B1-L-12J11BF02 were the most consistent at reducing damage, larval growth (fitness), and fecundity of WSS. The challenge will be to maintain this level of efficacy as the Canada Western Red Spring phenotype is reintroduced into the germplasm. Our study suggests solid-stem cultivars are highly effective but prone to inconsistent performance and should therefore be integrated into a holistic strategy for WSS that includes agronomics and biocontrol.

Clark, W. D., Reyes-Valdes, M. H., Bond, J. and Kantartzi, S. K. 2013. Performance of LS97-1610בSpencer’ soybean recombinant inbred line population segregating for resistance toFusarium virguliforme. Can. J. Plant Sci. 93: 1179-1185. Sudden death syndrome (SDS) is a devastating disease in soybean which is caused by Fusarium virguliforme. Sudden death syndrome resistance is a quantitative trait; therefore, development of resistant varieties requires understanding of complex genetics and environmental effect. In this study, we aimed to characterize 94 F_5:8 recombinant inbred (RI) lines derived from a cross between a resistant line for SDS, LS97-1610 and a susceptible cultivar, ‘Spencer’ and to identify sources of resistance. The RI lines were evaluated for their relative resistance (RR) to SDS along with the parents in four different environments; two years (2009 and 2010) and two locations (Carbondale and Valmeyer, IL). Analysis of variance revealed significant interactions between genotype and environment in each year of experimentation and in 2-yr combined data. Broad-sense heritability was estimated by ANOVA results, and it was moderate (61%). These results indicate that SDS resistance is partially unpredictable due to environmental influence. Ten RI were identified to have a RR with no significant differences from LS97-1610 and two of them had a RR lower than resistant parent. These stable RI across environments were used for further evaluation in breeding programs. Additionally, data obtained from field evaluation can be used in combination with molecular data to study the effect of quantitative trait loci (QTL) with the environment. The identification of common QTL across environments with consistent expression is the ultimate goal of every marker-assisted selection program.

Byker, H. P., Soltani, N., Robinson, D. E., Tardif, F. J., Lawton, M. B. and Sikkema, P. H. 2013. Glyphosate-resistant Canada fleabane [Conyza canadensis(L). Cronq.]: Dose response to glyphosate and control with postemergence herbicides in soybean in Ontario. Can. J. Plant Sci. 93: 1187-1193. Glyphosate-resistant (GR) Canada fleabane was first reported in Ontario in 2010. Twelve field studies were conducted over a 2-yr period (2011, 2012) to determine the biologically effective dose of glyphosate in the field and to determine the efficacy of postemergence herbicides for control of GR Canada fleabane. A dose between 1271 and 5652 g a.e. ha^-1 was required for a 50% reduction in Canada fleabane biomass depending on site and year. To achieve acceptable (>95%) control with glyphosate, 18 840 to 43 200 g a.e. ha^-1 of glyphosate was required across all sites. Therefore application of glyphosate at these doses for acceptable (>95%) control is not economical. None of the postemergence herbicides labeled for use in soybean provided acceptable (>95%) control, with cloransulam providing the greatest control (67%) 4 wk after application. Therefore, GR Canada fleabane must be controlled prior to soybean emergence as current herbicides registered in soybean for postemergence use do not provide sufficient control to prevent soybean yield loss.

Cavalieri, A., Lewis, D. W. and Gulden, R. H. 2013. Residual weeds in winter wheat in Manitoba. Can. J. Plant Sci. 93: 1195-1200. Winter wheat production has increased from a few thousand to several hundred thousand acres in Manitoba over the past decade. In the summer of 2009, a mid-season weed survey was conducted to establish a benchmark of the residual weed community in winter wheat in three ecoregions in Manitoba. Field histories and herbicide management practices were also recorded for all 84 fields surveyed. Traditionally important weeds in other field crops such as green foxtail [Setaria viridis (L.) Beauv.], wild oats (Avena fatua L.) and wild buckwheat (Polygonum convolvulus L.) were also the most abundant weeds in winter wheat. A species never observed in production fields, waterpod [Ellisia nyctelea (L.) L.] was documented. Neither Japanese brome grass (Bromus japonicum L.) nor downy brome (Bromus tectorum L.), winter annuals often prevalent in winter wheat, were found.

Faye, A., Dalpé, Y., Ndung'u-Magiroi, K., Jefwa, J., Ndoye, I., Diouf, M. and Lesueur, D. 2013. Evaluation of commercial arbuscular mycorrhizal inoculants. Can. J. Plant Sci. 93: 1201-1208. In order to improve the use of commercial inoculants, 12 arbuscular mycorrhizal fungi (AMF) inoculants were evaluated in a two-step experiment under greenhouse conditions using maize. First, commercial mycorrhizal inoculants were propagated in a trap pot culture experiment under sterilized sand to evaluate their potential for maize (Zea may L.) root colonization as compared with an indigenous soil inoculum and to survey the AMF species present in the products. Three inoculants significantly increased root colonization levels compared with a soil inoculum. Instead of 12 declared AMF species, 13 fungal strains were extracted from the pot culture survey, including five undeclared species, while four declared species did not produce spores. In a second experiment, commercial products were inoculated into soil to assess their impact on maize growth and yield. Six weeks after planting, seven inoculants increased root colonization levels compared with control soil, while only three inoculants increased slightly the shoot biomass of maize plants. These experiments highlight the need to pre-evaluate commercial mycorrhizal inoculants on a selected crop and regional soil before launching large-scale field use.

Sharifi, M., Cheema, M., Mahoney, K., LeBlanc, L. and Fillmore, S. 2013. Evaluation of liming properties and potassium bioavailability of three Atlantic Canada wood ash sources. Can. J. Plant Sci. 93: 1209-1216. Wood ash has the potential to enhance productivity in agricultural systems by influencing soil pH and nutrient availability. The liming properties and fertility values of wood ash from three Atlantic wood ash sources were evaluated in this study. The liming properties were tested using three wood ash sources [JD Irving (IR), New Page (NP), and Brooklyn Power (BP)] and two local lime sources in an 8-mo incubation experiment at 25°C. Soil pH was measured 14 times during the incubation. Availability of potassium (K) in wood ash was evaluated in a greenhouse setting with a K-deficient soil using annual ryegrass as the test plant. Total plant K and P uptake and Mehlich-3 extractable K and P were used as predictors of nutrient bioavailability. Wood ash application increased soil pH to the maximum level within the first 50 d after application and stabilized soil pH for 8 mo. The measured effective calcium carbonate equivalent of ashes relative to Mosher lime average among two soils were in order of BP (32)>IR (25)>NP (16). About 96, 38, and 71% of total K in IR, NP and BP ash sources, respectively, were bioavailable for ryegrass in 115 d. Although soil was not P deficient, soil P bioavailability (Mehlich III extractable P) was enhanced by 14 and 48% in NP and BP wood ash treatments, respectively, whereas P bioavailability decreased by 24% in the IR ash treatment. The results clearly demonstrate that these sources of wood ash can be considered as an effective liming agent and source of K in agricultural production systems.

Gravel, V., Dorais, M. and Ménard, C. 2013. Organic potted plants amended with biochar: its effect on growth andPythiumcolonization. Can. J. Plant Sci. 93: 1217-1227. Even though the benefits from the use of charcoal in agriculture have been known for a long time, little biochar is utilized in agriculture. Therefore, we hypothesized that biochar amendment to an organic potting soil improves plant growth without promoting plant root pathogens such as Pythium ultimum. Growth of sweet pepper, lettuce, basil, geranium and coriander grown in an organic potting soil containing a commercially available biochar (1:1 vol:vol) was compared with an unamended potting soil. Macronutrients (NPK) were supplied through application of an organic liquid fertilizer three times a week via injection irrigation. The effect of biochar amendment on P. ultimum colonization and infection was also evaluated in a sub-sample. No effect of the biochar amendment on growth was observed for sweet pepper and geranium. On a dry weight basis, coriander shoot growth was 45% greater in the biochar-amended potting soil, while a decrease of 44% in shoot biomass was observed for lettuce. The negative growth impact of biochar was not related to a phytotoxicity effect as water extract from biochar did not affect seed germination. For Pythium-inoculated plants, root colonization by the pathogen was higher for all crops in potting soil amended with biochar, except for coriander. However, despite the fact that biochar offered a good environment for P. ultimum development as shown by a higher root colonization rate, no visible signs of damage to the root system or to plant development were observed. Soil respiration was lower when biochar was present in the growing medium, which could be related to a lower root biomass and the biochar-specific properties on greenhouse gases rather than to a reduction in the potting media biological activity. In conclusion, replacement of an important proportion of organic growing media with biochar may be beneficial in terms of plant growth and CO₂ emission, but may also offer a good environment for Pythium ultimum development.

Kutcher, H. R., Turkington, T. K., Clayton, G. W. and Harker, K. N. 2013. Response of herbicide-tolerant canola (Brassica napusL.) cultivars to four row spacings and three seeding rates in a no-till production system. Can. J. Plant Sci. 93: 1229-1236. Appropriate management practices are important to reduce input costs and to optimize yield and crop quality. The objective of this study was to determine the optimum row spacing (23, 31, 46 and 61 cm) and seeding rate (3.2, 6.4 and 9.6 kg ha^-1, or 87, 173 and 260 seeds planted m^-2) for two herbicide-tolerant canola (Brassica napus L.) cultivars (an open-pollinated and a hybrid) under a no-till production system. Plant density and yield varied with row spacing, with the effect being linear in both cases. Plant density decreased with wider row spacing, from 112 plants m^-2 at the 23-cm row spacing to 83 plants m^-2 at the 61-cm row spacing. Yield decreased with wider row spacing, from 2397 kg ha^-1 at the 23-cm row spacing to 2138 kg ha^-1 at the 61-cm row spacing. Results from this study indicate that herbicide-tolerant cultivars of canola grown in no-till production systems under conditions of adequate soil fertility, effective weed management, minimal disease pressure, and good flea beetle control, produced the highest plant densities and yields at row spacing of 24-31 cm, that seeding rates in the range of 3.2-9.6 kg ha^-1 had no effects on yield, and that a hybrid cultivar performed better than open-pollinated cultivars in terms of plant density, earliness and duration of flowering, and seed size. The study helps to better define the response of plant density and seed yield in herbicide-tolerant canola cultivars to changes in row spacing and seeding rate. In particular, the results of this study suggest that plant density may not be a reliable predictor of canola yield, although row spacing is an important consideration.

Robertson, S. M., Jeffrey, S. R., Unterschultz, J. R. and Boxall, P. C. 2013. Estimating yield response to temperature and identifying critical temperatures for annual crops in the Canadian Prairie region. Can. J. Plant Sci. 93: 1237-1247. Historical yield and temperature data, by municipal district for the three prairie provinces, are used to estimate the marginal effect of exposure to specific temperatures in defined ranges during the growing season. Incorporating these non-linear temperature effects into the model improves yield forecasting for Canadian prairie annual crops over models that use average temperatures or growing degree days. Critical maximum temperatures at which yields decline, calculated for winter wheat, spring wheat, durum wheat, barley, spring rye, fall rye, oats, canola and flax, range between 28 and 34°C, depending on the crop. Additional critical minimum and maximum temperatures are estimated using the marginal effect of exposure to specific temperatures in defined ranges. Estimates of critical maximum temperatures and their marginal impact on yields are important for research and policy analysis on various issues and problems, including climate change, risk management instruments such as crop insurance, and development of heat tolerant crop varieties.

Yang, F., Liu, F.-h. and Rowland, G. 2013. Effects of diurnal temperature range and seasonal temperature pattern on the agronomic traits of fibre flax (Linum usitatissimumL.). Can. J. Plant Sci. 93: 1249-1255. Three cultivars of fibre flax (Linum usitatissimum L.), Viking, Argos and Ariane, were used to study the effect on various agronomic traits of diurnal temperature ranges (DIF) and seasonal temperature patterns (STP) applied throughout the crop growth period. Diurnal temperature ranges were set at 5, 10 and 15°C with the same daily mean temperature and accumulated growing degree days (GDDa), under a parabolic STP. Seasonal temperature patterns were set following parabolic, anti-parabolic and quasi-horizontal configurations with DIF set at 10°C. The results showed that DIF or cultivar had a significant influence on the biomass, plant height (PH), stem diameter (SD), length of technical stem (LTS), weight of technical stem (WTS), fibre weight (FW), fibre content (FC) and seed weight per pot (SWp). Seasonal temperature pattern also had a significant influence on these traits except for WTS and FW. Significant interactions were observed between DIF and cultivar, affecting all traits with the exception of FW, and between STP and cultivar, affecting biomass, PH, SD and WTS. Diurnal temperature range set at 10°C was optimal for biomass, PH, SD, LTS, WTS, and FW, while DIF set at 5°C benefited FC and SWp. Among the different STP configurations, anti-parabolic pattern was optimal for biomass, PH, SD, LTS and FC, and the quasi-horizontal pattern best fit SWp. In conclusion, the combination of DIF set at 10°C and anti-parabollic STP provided the most favorable temperature conditions for fibre flax growth, which is the situation with winter flax production in Yunnan, China.

Fowler, D. B. 2013. Swainson hard red winter wheat. Can. J. Plant Sci. 93: 1257-1259. Swainson is a medium tall, high-yielding, stem and leaf rust resistant winter wheat (Triticum aestivum L.) that is registered for production in western Canada. It is a hard red winter wheat cultivar that is eligible for grades of the Canada Western General Purpose (CWGP) wheat class, which was created in 2008 to encourage the development of cultivars to fill the high energy demands of the biofuel and livestock feed markets in western Canada. Its high yield potential has been particularly evident on dry land in Saskatchewan where its grain yield was 116% of CDC Buteo, the Canada Western Red Winter Wheat Class grain quality check cultivar, and 110% of Accipiter and 117% of CDC Falcon, the high-yielding check cultivars. High grain yield potential of low protein concentration grain and rust resistance make Swainson a good fit for the CWGP class.

Tamburic-Ilincic, L. and Smid, A. 2013. OAC Flight soft red winter wheat. Can. J. Plant Sci. 93: 1261-1263. OAC Flight is a soft red winter wheat (Triticum aestivum L.) cultivar registered for Ontario, Canada. It has high grain yield, with good pastry quality and similar resistance to Fusarium head blight (FHB) as the moderately susceptible check Emmit. OAC Flight is well adapted for the winter wheat growing areas of South Western Ontario.

Pozniak, C. J. 2013. CDC Desire durum wheat. Can. J. Plant Sci. 93: 1265-1270. CDC Desire durum wheat is adapted to the durum production area of the Canadian prairies. This conventional height durum wheat cultivar combines high grain yield potential with high grain pigment and protein concentrations and low grain cadmium. CDC Desire is strong-strawed and is earlier maturing than all check cultivars. CDC Desire expresses disease resistance similar to the current check cultivars.

Duguid, S. D. and Rashid, K. Y. 2013. Prairie Sapphire flax. Can. J. Plant Sci. 93: 1271-1275. Prairie Sapphire, a medium-early maturing oilseed flax (Linum usitatissimum L.), was released in 2009 by Agriculture and Agri-Food Canada, Morden Research Station, Morden, Manitoba. Developed from the cross Macbeth/FP2030 made in 1998, Prairie Sapphire was evaluated in the Flax Cooperative Trials (2005-2007) before being registered in 2009. Prairie Sapphire's desirable combination of agronomic traits with its significantly improved oil and meal protein content should make it a useful cultivar for producers and the flax industry.

Poysa, V., Woodrow, L. and Yu, K. 2013. AAC Malden soybean. Can. J. Plant Sci. 93: 1277-1279. AAC Malden is a high-yielding, high-protein, large-seeded, soybean cyst nematode (SCN) resistant food grade soybean [Glycine max (L.) Merr.] cultivar with yellow hila and acceptable processing quality for foreign and domestic tofu, soymilk and miso markets. It was developed at Agriculture and Agri-Food Canada (AAFC) Greenhouse and Processing Crops Research Centre (GPCRC), Harrow, Ontario. AAC Malden is adapted to areas of southwest Ontario with 3100 or more crop heat units and has a relative maturity of 2.3 (MG 2.3).

Schroeder, W., Soolanayakanahally, R. and Lindquist, C. 2013. Okanese poplar. Can. J. Plant Sci. 93: 1281-1283. Okanese poplar is a male, winter-hardy and drought-resistant hybrid poplar tree released by Agriculture and Agri-Food Canada (AAFC), Agroforestry Development Centre (ADC) for the Canadian prairies and United States northern Great Plains. Okanese is named for the Cree Chief Okanis founding chief of Okanese First Nation located in the File Hills area of southern Saskatchewan.

Schroeder, W., Soolanayakanahally, R. and Lindquist, C. 2013. AC Sundancer™ Poplar. Can. J. Plant Sci. 93: 1285-1287. AC Sundancer™ is a male, winter-hardy hybrid poplar tree released by Agriculture and Agri-Food Canada (AAFC), Agroforestry Development Centre for the Canadian prairies and United States northern Great Plains. The name AC Sundancer™ was chosen as it depicts the striking upright growth habit of the tree.