Effect of wheat seed colour on the incidence and severity of red smudge and black point caused by Pyrenophora tritici-repentis

Non-Peer ReviewedPyrenophora tritici-repentis (Died.) Drechs. (anamorph Drechslera tritici-repentis (Died.) Shoemaker) causes red smudge, black point and dark smudge (Fernandez et al., 1998; 2001; Francl and Jordahl, 1993). This discoloration could result in downgrading due to low tolerance levels in the top grades (Canadian Grain Commission, 1994). Incorporation of disease resistance into all wheat classes would therefore be of economic benefit to producers. Fernandez et al. (2001) determined that cultivars in all four wheat quality classes tested were susceptible to P. tritici-repentis but that they differed in the predominant type and/or intensity of the discoloration and in incidence and severity of the infection. Some of the differences in the incidence and severity of the discoloration among cultivars appeared to be related to seed colour. Because there were differences also within classes not related to seed colour, the impact of seed colour per se on the development of kernel discoloration caused by P. tritici-repentis could not be accurately assessed. The objective of this study was to assess the incidence and severity of kernel discoloration caused by P. tritici-repentis in near-isogenic lines for seed coat colour so that genotypic effects could be separated from seed colour

Effect of leaf spot severity on yield and quality of durum wheat

Non-Peer ReviewedLeaf spots in wheat (Triticum aestivum L.) are important in Saskatchewan even under dry conditions (Fernandez et al., 2002). Durum wheat (T. turgidum L. var. durum) cultivars presently grown in western Canada are susceptible to leaf spots. The most common leaf spotting disease in durum wheat is tan spot [Pyrenophora tritici-repentis (Died.) Drechs. (anamorph Drechslera triticirepentis (Died.) Shoemaker)] Leaf spots are believed to cause reductions in yield and quality. The most widely used approach to measure the effect of leaf diseases on yield and its components has been the use of fungicides (Duczek and Jones-Flory, 1994; Eyal, 1972; Hosford and Busch, 1974; Rees and Platz, 1983). Inconsistent results with fungicide use in wheat were also reported (Bailey et al., 1992; Stover et al., 1996; Wang et al., 2002). In some cases, fungicide effects were not directly related to the occurrence of disease (Fehrmann et al., 1978; Wang et al., 2002), which makes them an unreliable tool to assess the effect of leaf spots on plant growth. To accurately quantify the negative effects of leaf spots on yield and quality, an approach other than disease control by fungicide application is necessary. The objective of this study was to evaluate the use of genotypes near-isogenic for leaf spot reaction to quantify the effect of leaf spots on grain yield and quality of durum wheat

Tillage system and cropping sequence effects on common root rot of barley in eastern Saskatchewan

Non-Peer ReviewedFusarium head blight (FHB) in barley has been spreading on the Canadian Prairies for the last decade. Fusarium spp. causing FHB can also cause crown/root rot of cereal crops. It is therefore of interest to determine the impact of agronomic practices on fungal populations associated with root rot of barley. From 1999 to 2001, 137 barley crops were sampled in eastern Saskatchewan for severity of subcrown internode discoloration and percent isolation of fungi. Cochliobolus sativus was the most commonly isolated fungus, whereas the most commonly isolated Fusarium spp. included the FHB pathogens F. avenaceum, F. culmorum and F. graminearum. Discoloration caused by C. sativus was favored by conventional-till, whereas Fusarium spp. increased in reduced tillage systems. Barley grown after a cereal-summerfallow (or summefallow-cereal) sequence under conventional- or minimum-till had increased levels of C. sativus. Fusarium spp. were most affected by the previously grown crop(s); they were more common in barley grown after a noncereal than a cereal, and after two noncereals, or a noncereal alternated with summerfallow. Previous glyphosate applications were associated with lower C. sativus, and higher Fusarium spp., levels in barley grown under minimum till. This suggests changes in fungal communities; however, the mechanism(s) responsible for these changes in fungal levels are not known. Increased infection of ground/underground tissue by FHB pathogens might contribute to its development in succeeding cereal crops, therefore measures aimed at reducing root/crown infections by Fusarium spp. might also help reduce FHB development

The effect of leaf spots on yield and quality of wheat in southern Saskatchewan

Non-Peer ReviewedAlthough leaf spots have been reported to have a negative effect on yield and quality, the magnitude of the effect of leaf spots on grain yield and quality of wheat cultivars grown on dryland in southern Saskatchewan is not known. Experiments were conducted at Swift Current (Brown soil) and Indian Head (Black soil) for three years to determine effects of leaf spots on grain yield, kernel weight, test weight and protein concentration of wheat. Two fungicides, Folicur 3.6F and Bravo 500 were applied at different growth stages in order to diversify the severity of leaf spots. Three common wheat (T. aestivum L.) cultivars - AC Domain, Laura and AC Elsa and three durum wheat (T. turgidum L. var durum) cultivars with different levels of leaf spot susceptibility were used in this study. The control of leaf spots by fungicides often did not cause an increase of yield, kernel weight, test weight or grain protein concentration in the drier Prairies where yield potential is relatively low. Fungicide treatments significantly increased yield in only two of six location-years (Folicur applied at head emergence in 1997 (0.07-0.13 t ha-1) (P < 0.05) and Folicur applied at flag emergence and/or head emergence in 1998 (0.41-0.47 t ha-1) (P < 0.001) at Indian Head. Fungicide applications significantly increased kernel weight in only three of six location-years (applications at flag leaf emergence at Swift Current (0.8-1.1 mg) (P < 0.05) and Indian Head (1.8-2.0 mg) (P < 0.001) in 1998 and at Indian Head in 1999 (10-1.1 mg) (P < 0.01). An increase of grain protein concentration was only found in treatments of Bravo applications at Indian Head in 1998 (0.3-0.7%) (P < 0.001). It seems that the control of leaf spots tended to have higher effect on yield and quality at Indian Head than Swift Current, it could be attributed to better controls of leaf spots at early milk stage (P < 0.001) and/or higher yield potential at Indian Head (P < 0.001). Although the cultivars used in this study have different leaf spot susceptibility (P < 0.001), there were no consistent cultivar differences in the effectiveness of the fungicides on control of leaf spots and on the yield, kernel weight and other quality characteristics. Leaf spots are a common and potentially severe foliar disease of wheat. Many studies have reported that leaf spots have a negative effect on grain yield (Eyal and Ziv, 1974; King, et al., 1983; McKendry and Henke, 1994), test weight (Milus, 1994) and milling quality (Mckendry et al., 1995), especially under environments favorable for the development of leaf spots or under intensive management such as irrigation (Duczek and Jones-Flory, 1994) and high N fertilizer rates (Howard, et al., 1994). In the past decade there has been an increase in the incidence of leaf spotting diseases of wheat in southern Saskatchewan, Canada. These are attributed mainly to Pyrenophora tritici-repentis (tan spot), Septoria nodorum and S. tritici (septoria leaf blotch complex) and all current spring wheat cultivars are susceptible to this disease complex - 333 - (Fernandez, et al., 1996; Fernandez, et al., 1998). Consequently there is increased pressure on producers to chemically control diseases that might affect yield and quality. The magnitude of the impact of leaf spots on grain yield and quality of wheat cultivars grown on dryland in this area, however, is not known. Research on these issues is therefore necessary to provide informed guidelines for use by producers. The objective of this study was to determine the effect of leaf spots on grain yield, kernel weight, test weight and protein concentration of spring common (T. aestivum L.) and durum (T. turgidum L. var durum) wheat in southern Saskatchewan

Tillage system and cropping sequence effects on Fusarium head blight in barley in eastern Saskatchewan

Non-Peer ReviewedFusarium head blight (FHB) in barley is well established in the eastern Canadian Prairies and appears to be moving westward. A survey of 192 barley crops in eastern Saskatchewan was conducted to determine the impact of agronomic practices on FHB (1999-2002) and Fusarium damaged kernels (FDK) (2000-2001). The most common species isolated from spikes/kernels were F. sporotrichioides, F. avenaceum, and F. graminearum, followed by F. poae and F. culmorum. Disease tended to be higher under minimum- than conventional- and/or zero-till. F. sporotrichioides was favored by a previous cereal crop, whereas F. avenaceum was higher after a pulse crop, and F. graminearum decreased after a pulse but not an oilseed crop. The latter two pathogens were also more prevalent after diversified cropping sequences than after two cereal crops. Summerfallow, or summerfallow alternated with cereals, decreased FDK. Previous glyphosate (Group 9 herbicides) use was associated with increased infection by all Fusarium spp., whereas Group 1 herbicides were associated with increased infection by F. poae and F. sporotrichioides. Number of previous glyphosate applications was also correlated with FHB caused by F. avenaceum and F. graminearum. We concluded that in eastern Saskatchewan, barley grown under minimum-till where glyphosate had been sprayed and following diversified cropping sequences would sustain the greatest damage due to FHB/FDK caused by F. avenaceum and F. graminearum

The effect of leaf spots on yield and quality of wheat in southern Saskatchewan

Non-Peer ReviewedAlthough leaf spots have been reported to have a negative effect on yield and quality, the magnitude of the effect of leaf spots on grain yield and quality of wheat cultivars grown on dryland in southern Saskatchewan is not known. Experiments were conducted at Swift Current (Brown soil) and Indian Head (Black soil) for three years to determine effects of leaf spots on grain yield, kernel weight, test weight and protein concentration of wheat. Two fungicides, Folicur 3.6F and Bravo 500 were applied at different growth stages in order to diversify the severity of leaf spots. Three common wheat (T. aestivum L.) cultivars - AC Domain, Laura and AC Elsa and three durum wheat (T. turgidum L. var durum) cultivars with different levels of leaf spot susceptibility were used in this study. The control of leaf spots by fungicides often did not cause an increase of yield, kernel weight, test weight or grain protein concentration in the drier Prairies where yield potential is relatively low. Fungicide treatments significantly increased yield in only two of six location-years (Folicur applied at head emergence in 1997 (0.07-0.13 t ha-1) (P < 0.05) and Folicur applied at flag emergence and/or head emergence in 1998 (0.41-0.47 t ha-1) (P < 0.001) at Indian Head. Fungicide applications significantly increased kernel weight in only three of six location-years (applications at flag leaf emergence at Swift Current (0.8-1.1 mg) (P < 0.05) and Indian Head (1.8-2.0 mg) (P < 0.001) in 1998 and at Indian Head in 1999 (10-1.1 mg) (P < 0.01). An increase of grain protein concentration was only found in treatments of Bravo applications at Indian Head in 1998 (0.3-0.7%) (P < 0.001). It seems that the control of leaf spots tended to have higher effect on yield and quality at Indian Head than Swift Current, it could be attributed to better controls of leaf spots at early milk stage (P < 0.001) and/or higher yield potential at Indian Head (P < 0.001). Although the cultivars used in this study have different leaf spot susceptibility (P < 0.001), there were no consistent cultivar differences in the effectiveness of the fungicides on control of leaf spots and on the yield, kernel weight and other quality characteristics. Leaf spots are a common and potentially severe foliar disease of wheat. Many studies have reported that leaf spots have a negative effect on grain yield (Eyal and Ziv, 1974; King, et al., 1983; McKendry and Henke, 1994), test weight (Milus, 1994) and milling quality (Mckendry et al., 1995), especially under environments favorable for the development of leaf spots or under intensive management such as irrigation (Duczek and Jones-Flory, 1994) and high N fertilizer rates (Howard, et al., 1994). In the past decade there has been an increase in the incidence of leaf spotting diseases of wheat in southern Saskatchewan, Canada. These are attributed mainly to Pyrenophora tritici-repentis (tan spot), Septoria nodorum and S. tritici (septoria leaf blotch complex) and all current spring wheat cultivars are susceptible to this disease complex - 333 - (Fernandez, et al., 1996; Fernandez, et al., 1998). Consequently there is increased pressure on producers to chemically control diseases that might affect yield and quality. The magnitude of the impact of leaf spots on grain yield and quality of wheat cultivars grown on dryland in this area, however, is not known. Research on these issues is therefore necessary to provide informed guidelines for use by producers. The objective of this study was to determine the effect of leaf spots on grain yield, kernel weight, test weight and protein concentration of spring common (T. aestivum L.) and durum (T. turgidum L. var durum) wheat in southern Saskatchewan

Genotype difference in kernel discolorations in CWRS and CWAD wheats

Non-Peer ReviewedKernel discolorations of wheat, such as black point (including smudge and penetrated smudge), red smudge and Fusarium-damaged kernel (FDK), are important downgrading factors in western Canada. This study was undertaken to determine cultivar differences in incidences of these kernel discolorations and their downgrading effects in CWRS and CWAD wheats. Grain samples were taken at maturity from six CWRS and four CWAD cultivars in a four-year (1997-2000) field study at six sites: one in the Grey soil zone, two in the Brown soil zone and three in the Black soil zone in western Canada. For CWRS cultivars, Garnet tended to have lower incidences in black point, smudge and FDK and resulted in the least downgrading compared with other CWRS cultivars. For CWAD cultivars, Kyle tended to have lower incidence of black point, Plenty had less smudge caused downgrading effects, DT 369 had lower penetrated smudge incidence, but higher red smudge incidence, and Plenty tended to have severer FDK-caused downgrading effects compared with other CWAD cultivars. CWAD class had higher frequency of downgrading than CWRS class and it usually had higher incidences of all kernel discolorations (black point, smudge, penetrated smudge, red smudge and FDK) and greater downgrading effects than CWRS class

Enhancing MRI Reconstruction Efficiency Through Multi-GPU Parallelization

Dynamic cardiac MRI (cMRI) is essential for diagnosing cardiovascular diseases, demanding high resolution and image quality. However, achieving superior quality increases data volume and reconstruction time. To tackle this, we propose a solution using parallel imaging and Compressed Sensing (CS) with high-capacity computing devices (e.g., GPUs) for accelerated reconstruction of undersampled data. GPU mem- ory limitations, especially in 3D cMRI, present challenges. Our scalable approach splits the reconstruction problem and employs multiple GPUs (or multiple multi-core CPUs) to per- form multiple optimizations in parallel using the well-known NESTA algorithm, while preserving smoothness between ad- jacent frames in the temporal dimension. Preliminary results on 5D cMRI reconstruction show that our parallel proposal achieves equivalent reconstruction quality in less time, en- abling larger data processing and cost reduction with smaller, more affordable GPUs, as opposed to a single, highly expensive GPU. Moreover, the adoption of the OpenCLIPER frame- work eliminates proprietary GPU technologies. Exploration of adaptability to other sampling schemes opens new possibilities in this field.This work is partially supported by MINECO under grants TEC2017-82408-R, PRE2018-086922, and by the Agencia Estatal de Investigación under grants PID2020- 115339RB-I00 and TED2021-130090B-I00

Poly(triazolyl methacrylate) glycopolymers as potential targeted unimolecular nanocarriers

© The Royal Society of Chemistry 2019.Synthetic glycopolymers are increasingly investigated as multivalent ligands for a range of biological and biomedical applications. This study indicates that glycopolymers with a fine-tuned balance between hydrophilic sugar pendant units and relatively hydrophobic polymer backbones can act as single-chain targeted nanocarriers for low molecular weight hydrophobic molecules. Non-covalent complexes formed from poly(triazolyl methacrylate) glycopolymers and low molecular weight hydrophobic guest molecules were characterised through a range of analytical techniques-DLS, SLS, TDA, fluorescence spectroscopy, surface tension analysis-and molecular dynamics (MD) modelling simulations provided further information on the macromolecular characteristics of these single chain complexes. Finally, we show that these nanocarriers can be utilised to deliver a hydrophobic guest molecule, Nile red, to both soluble and surface-immobilised concanavalin A (Con A) and peanut agglutinin (PNA) model lectins with high specificity, showing the potential of non-covalent complexation with specific glycopolymers in targeted guest-molecule delivery.Peer reviewedFinal Published versio