172 research outputs found

    Relative performance of four midge-resistant wheat varietal blends in western Canada

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    Non-Peer ReviewedOrange wheat blossom midge, Sitodiplosis mosellana (GĂ©hin), causes significant yield losses to spring wheat in western Canada in severe infestations. To mitigate losses, midge-resistant wheat varietal blends, consisting of cultivars carrying the Sm1 midge resistance gene and 10% interspersed midge susceptible refuge, have been made available to farmers. To test their performance relative to conventional midge-susceptible cultivars, four varietal blends were grown during four consecutive years, at eight locations in the provinces of Manitoba Saskatchewan and Alberta, in comparison to four conventional, midge-susceptible cultivars. Midge damage was higher in 2007 and 2010 than in 2008 and 2009. In general, the varietal blends, as a group, yielded more grain than the susceptible cultivars, especially when grown in environments with high midge pressure (5.5 - 35% seed damage). In environments with low midge pressure (0 – 2.6% seed damage), the varietal blend average yield advantage was smaller but still significant, indicating that some of the varietal blends had additional superior attributes, in addition to midge resistance

    The effect of incorporating the midge resistance (Sm1) gene in wheat

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    Non-Peer ReviewedOrange wheat blossom midge, Sitodiplosis mosellana (GĂ©hin), was first detected in Manitoba in 1901, but now is present in all three prairie provinces of western Canada. In severe infestations, this insect may cause significant yield losses to spring wheat. To mitigate losses, midge-resistant wheat varietal blends, consisting of cultivars carrying the Sm1 midge resistance gene and 10% interspersed midge susceptible refuge, are now available to farmers. The refuge prevents this resistance to be overcome by the insect. To test the field performance of these varietal blends, relative to conventional midge-susceptible cultivars, four varietal blends were grown during four consecutive years, at eight locations in the provinces of Manitoba Saskatchewan and Alberta, in comparison to four conventional, midge-susceptible cultivars. Midge damage was higher in 2007 and 2010, than in 2008 and 2009. In general, the varietal blends, as a group, yielded more grain than the susceptible cultivars, especially when grown in environments with high midge pressure (5.5 - 35% seed damage). In environments with low midge pressure (0 – 2.6% seed damage), the varietal blend average yield advantage was smaller but still significant, indicating that some of the varietal blends had additional superior attributes, in addition to midge resistance. Significant differences in midge damage were observed within the resistant and the susceptible groups of the cultivars tested. Midge resistance did not protect wheat against loss of market grade

    Development of a molecular marker for rust resistance genes Sr39 and Lr35 in wheat breeding lines

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    Polymorphic DNA bands were identified between a near iso-isogenic line of wheat carrying both stem (Sr39) and leaf (Lr35) rust resistance genes and the recurrent line Thatcher (Tc) which lacks these genes. Both resistance genes are located on a translocated chromosomal segment derived from Aegilops speltoides and thus are genetically linked. The primers used to generate polymorphic bands were 3'-anchored inter-simple sequence repeat primers which identified genomic microsatellites with a repeated motif of 3 nucleotides in length. The primers were used singly to amplify genomic segments which were flanked by inversely orientated, closely spaced, identical microsatellite sequences. One of the polymorphic bands, a 900 base pair band, was completely linked to the Sr39 and Lr35 rust resistance genes in the segregating population used in this study. After cloning and sequencing this polymorphic band, the inter-simple sequence repeat marker was converted to a sequence characterized amplified region marker by designing primer sets which amplify a single, easily resolved band from DNA of plants with Sr39/Lr35 genes. This marker is present in six wheat lines carrying the Sr39 and Lr35 genes on the translocated chromosome segment from Ae. speltoides, The marker has facilitated efforts to breed Canada Prairie Spring and Canada Western Extra Strong lines with these rust resistance genes

    Sensitive and specific identification by polymerase chain reaction of Eimeria tenella and Eimeria maxima, important protozoan pathogens in laboratory avian facilities

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    Eimeria tenella and Eimeria maxima are important pathogens causing intracellular protozoa infections in laboratory avian animals and are known to affect experimental results obtained from contaminated animals. This study aimed to find a fast, sensitive, and efficient protocol for the molecular identification of E. tenella and E. maxima in experimental samples using chickens as laboratory avian animals. DNA was extracted from fecal samples collected from chickens and polymerase chain reaction (PCR) analysis was employed to detect E. tenella and E. maxima from the extracted DNA. The target nucleic acid fragments were specifically amplified by PCR. Feces secreting E. tenella and E. maxima were detected by a positive PCR reaction. In this study, we were able to successfully detect E. tenella and E. maxima using the molecular diagnostic method of PCR. As such, we recommended PCR for monitoring E. tenella and E. maxima in laboratory avian facilities

    Elimination of onchocerciasis in Ecuador: findings of post-treatment surveillance.

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    BACKGROUND: The Esmeraldas focus of onchocerciasis in Ecuador expanded geographically during the 1980s and was associated with severe ocular and skin disease. Mass drug administration (MDA) with ivermectin started in 1991, initially once but later twice a year, in the principle endemic focus followed by all satellite foci. Treatment was stopped in 2009 when entomological assessments determined that transmission of Onchocerca volvulus had been interrupted. METHODS: Three years after the cessation of ivermectin treatment in 2012, as defined by the WHO guidelines for onchocerciasis elimination, blackfly collections were done in four sentinel sites in former hyperendemic areas. The presence of infective larvae in local vectors, Simulium exiguum and Simulum quadrivittatum, was assessed by detection of O. volvulus DNA by PCR. Additional flies captured in four extra-sentinel sites located in former hyper- and mesoendemic dispersed isolated areas were also assessed. RESULTS: The results from 68,310 captured blackflies, 40,114 from four sentinel villages in the previously hyperendemic areas (Corriente Grande, El Tigre, San Miguel on Río Cayapas and Naranjal on Río Canandé) and 28,197 from extra-sentinel locations, were all negative for the presence of O. volvulus. These extra-sentinel sites (Hualpí on Río Hoja Blanca, Capulí on Río Onzole, La Ceiba on Río Tululví and Medianía on Río Verde) were included to provide additional evidence of the impact of MDA on the transmission of O. volvulus in isolated endemic areas. CONCLUSIONS: Our data indicate that transmission of O. volvulus has been stopped in all endemic areas in Ecuador, including all satellite foci outside the main focus. These findings indicate that a strategy of ivermectin distribution twice a year to over 85% of the treatment-eligible population was effective in eliminating the infection from Ecuador in a focus with a highly competent primary vector, S. exiguum, and where the infection rates were equal to or greater than observed in many onchocerciasis foci in Africa

    UNBOUND

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    This adjective - ex-traor-di-nary, describes the creative talents of our graduating Fashion Design class of 2009. Their accomplishments are a true celebration of the three years of passion, hard work, and dedication of our student designers. It is our hope that family, friends and the fashion industry will enjoy the creative endeavours of the next generation of Canadian fashion talent from the Fashion design program at Fanshawe College in London, Ontario.https://first.fanshawec.ca/famd_design_fashiondesign_unbound/1006/thumbnail.jp

    UNBOUND

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    As part of the graduating class of Fanshawe College\u27s Fashion Design program, we are leaving the comfort of our cocoon to transform ourselves into full-fledged designers. Our aspirations have developed, and our goals have become clear. Reaching the heights of new age fashion is now possible with the wings that have been provided to us through the articulate direction and constant devotion of our advisors. With all of the help and guidance that our professors have given us, we are now able to go into the industry with confidence. The creativity within the Unbound show is a reflection of the intellect, devotion, passion and strong will that our designer\u27s possess. We have collected ourselves as individuals and have successfully pulled together in a collaborative effort to attain excellence and success in tonight\u27s Unbound fashion gala. - Graduating Class of 2009https://first.fanshawec.ca/famd_design_fashiondesign_unbound/1005/thumbnail.jp

    Molecular Characterization of Tb, a New Approach for an Ancient Brucellaphage

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    Tb (Tbilisi), the reference Brucellaphage strain, was classified as a member of the Podoviridae family with icosahedral capsids (57 ± 2 nm diameter) and short tails (32 ± 3 nm long). Brucellaphage DNA was double stranded and unmethylated; its molecular size was 34.5 kilobase pairs. Some sequences were found through RAPD analysis, TA cloning technology, and structural proteins were observed by using SDS-PAGE. Thus, the results have laid the foundation for the wider use of Brucellaphage’s basic mechanisms and practical applications

    Is the Y chromosome of Drosophila an evolved supernumerary chromosome?

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    The Y chromosomes of most Drosophila species are necessary for male fertility but they are not involved in sex determination. They have many puzzling properties that resemble the effects caused by B chromosomes. Classical genetic and molecular studies reveal substantial affinities between Y and B chromosomes and suggest that the Y chromosomes of Drosophila are not degenerated homologues of the X chromosomes, but rather that their Y chromosomes evolved as specialized supernumeraries similar to classical B chromosomes
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