Download or read book Molecular and Biometric Evaluation of Gray Leaf Spot and Southern Corn Leaf Blight Resistance in Maize written by David Matthew Bubeck and published by . This book was released on 1991 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Analysis of Southern Leaf Blight Gray Leaf Spot and Northern Leaf Blight Resistance Using Near isogenic Lines and Mapping Populations in Maize written by John Charles Zwonitzer and published by . This book was released on 2008 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: southern leaf blight, gray leaf spot, northern leaf blight, quantitative disease resistance, multiple disease resistance, disease resistance quantitative trail loci, near-isogenic lines, maize, recombinant inbred lines.
Download or read book Resistance to Gray Leaf Spot of Maize written by Jacqueline Marie Benson and published by . This book was released on 2013 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gray leaf spot (GLS) is a foliar disease of maize caused by Cercospora zeae-maydis and Cercospora zeina and quantitative resistance to GLS is important for maize production. A nested association mapping (NAM) maize population, consisting of 25 populations of 150 recombinant inbred lines, was used to identify quantitative trait loci (QTL) for GLS resistance. Trials were conducted in Blacksburg, VA, in a field with high natural incidence of GLS. A multivariate mixed model was used in ASReml3 to give the best linear unbiased predictions of disease severity ratings. QTL were selected using a general linear model selection procedure in SAS 9.2. Sixteen QTL, distributed across the maize genome, were identified using a likelihood of odds (LOD) selection threshold>4. Seven of these 16 QTL displayed allelic series with significantly higher and lower effects than the common parent allele. Near-isogenic lines (NILs) extracted from heterogeneous inbred families were developed to confirm and further finemap select QTL, targeting the loci with the greatest LOD scores from the model selection QTL analysis. Phenotypic characterization of the NILs confirmed that the loci in bins 1.04, 2.09 and 4.05 likely contribute significantly to disease resistance, with bins 1.04 and 2.09 conferring reductions in disease of 12% and 23%, respectively. In contrast, the susceptible allele in bin 4.05, which was associated with the distance between major veins, conferred an increase of 8.4%. This disease-related venation trait was confirmed using the 4.05 NILs. Genome-wide association studies revealed candidate genes related to the production of carotenoids, anthocyanins and antioxidant compounds that may play a role in cercosporin detoxification. Expression analysis of 1.05 NILs treated with cercosporin implicated a flavin-monooxygenase gene in cercosporin detoxification. Furthermore, significant associations between NAM parental allelic effects and parental phenotypes at the microscopic level for the 1.02 and 1.06 loci implicated callose plug and phenolic accumulation, respectively, in host defense. Elucidating the genetics of quantitative disease resistance loci provides breeders with valuable information that may enhance their ability to use molecular markers as a means to rapidly introgress loci that provide quantitative disease resistance.
Download or read book Evaluation of Maize Genotypes Against Southern Corn Leaf Blight written by Hassan Javed and published by LAP Lambert Academic Publishing. This book was released on 2012-03 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of foliar fungicides is less feasible because of farmers little knowledge about the suitable fungicide, however the application of resistant varieties is easy to adopt practice under our local conditions, therefore it is necessary to identify resistant maize genotypes.The project was aimed to determine the resistance level of different maize genotypes against the disease SCLB through the process of screening and evaluation, so that information acquired could be of vital use for the scientific research of phytopathologist and plant breeders and also for the farmers of the country. In vitro, pure cultures of the pathogen were prepared and their morphology was studied through microscopy.The study was conducted in the field by inoculation of genotypes by isolated pathogen. Disease assessment data was recorded along with various yield components.The results clearly showed that C. heterostrophus had significant effect on different maize genotypes. The genotypes that showed resistance to SCLB infection could be used in breeding programs.
Download or read book Quantitative Trait Loci Identification of Gray Leaf Spot Resistance in Maize written by Matthew L. Ramage and published by . This book was released on 2000 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Markers for Quantitative Trait Loci QTLs in Maize Gray Leaf Spot GLS Resistance written by Anke Lehmensiek and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissection of Gray Leaf Spot of Maize Through Functional Genomics written by Robert Louis Hirsch and published by . This book was released on 2014 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gray leaf spot, caused by Cercospora zeae-maydis, is a devastating disease of maize that reduces yields and increases management costs. C. zeae-maydis penetrates maize leaves through stomata, but the biological and molecular bases of this process are poorly understood. The goal of this research was to elucidate the biological parameters of stomatal infection in C. zeae-maydis, and to identify and characterize novel genetic pathways involved in stomatal sensing and pathogenesis. Histopathological observations of a GFP-expressing strain of C. zeae-maydis during infection of maize indicated that the fungus responded to host-derived stomatal cues during the infection process. C. zeae-maydis was observed exhibiting tropism toward non-host stomata, which ultimately implicated molecular oxygen as a possible stomatal chemoattractant. To explore the role of circadian rhythmicity in gray leaf spot, the putative central circadian oscillator gene FRQ in C. zeae-maydis was functionally disrupted and characterized. Interestingly, FRQ deletion strains were non-pathogenic when inoculated on maize leaves. Histological observations suggested that FRQ deletion strains failed to form appressoria in association with maize stomata. In order to identify other novel genes involved in pathogenesis, a collection of 1228 insertional mutants was created and assayed for infectious development. Ten mutants were identified, including one that was disrupted in RJP1, a putative epigenetic regulator of gene expression. In a related study, thirty-one genes were selected for functional disruption based on sequence similarity to known fungal regulatory genes. Analysis of these mutants indicated that GPA2, which encodes a putative G protein alpha subunit, was required for pathogenesis. Lastly, gene expression analysis during pre-penetration infectious development revealed widespread transcriptional reprogramming. Key findings from this research include the discovery of novel pathogenesis-related genes and potential roles for oxygen sensing and the fungal circadian clock in foliar pathogenesis. Furthermore, this research illuminated a previously unrecognized level of complexity underlying the regulation of stomatal infection during gray leaf spot of maize and established a foundation for future molecular investigations.
Download or read book Inheritance of Resistance to Gray Leaf Spot in Maize written by Nguyen Quoc Manh and published by . This book was released on 1977 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Evaluation of Special Grant Research on Southern Corn Leaf Blight written by United States. Cooperative State Research Service and published by . This book was released on 1976* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1991 with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Mapping and Components of Resistance to Cercospora Zeae maydis in Maize written by Stuart G. Gordon and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Gray leaf spot of maize (Zea mays L.), caused by Cercospora zeae-maydis (Tehon & Daniels), can greatly reduce grain yield worldwide. This study evaluated a novel source of resistance to C. zeae-maydis in the US Corn Belt and the Republic of South Africa (RSA), linked molecular markers to resistance loci using selective genotyping, and examined the components of resistance, sporulation, lesion length and number of lesions. The resistant maize inbred, VO613Y, was crossed to the susceptible inbred, Pa405, to obtain a population of 144 F2:3 progeny lines. These lines were evaluated at Wooster, Ohio, USA, and Cedara, RSA, for resistance to C. zeae-maydis based on percent leaf area affected (PLAA). A selected F3:4 population, derived by self-pollination of resistant and susceptible F2:3 lines, was evaluated at two Ohio locations over two seasons and at Cedara. Simple sequence repeat, restriction fragment length polymorphisms and resistance gene analog molecular marker data were obtained and analyzed based on F2:3 and F3:4 PLAA means across all environments by Kruskal-Wallis and ANOVA single factor analyses and composite interval mapping. Lesion length measurement, lesion counts and lesion sporulation data were taken on 4 resistant F3:4 progeny lines, 4 susceptible F3:4 progeny lines, and the parents. Quantitative trait loci located on two chromosome arms, 2L and 4L, together explained 47% of the variance in the F2:3 generation and 55% in the F3:4 generation across environments. Spearman rank correlations demonstrated that genotypes retained their relative ranks across environments. VO613Y-derived resistance extended the incubation period, resulted in the presence of fewer lesions and shortened the length of lesions. Taken together, this resulted in a lower percent leaf area affected by gray leaf spot. VO613Y and its resistant progeny did not inhibit spore production compared to Pa405 and its susceptible progeny, but resistant maize genotypes should contain fewer lesions capable of producing spores. The total number of spores produced on resistant maize genotypes should therefore be less than that produced on susceptible ones. These results indicate that VO613Y possesses QTL that may be introgressed into elite maize lines and deployed effectively in both southern Africa and the US Corn Belt.
Download or read book The Genetic Architecture of Quantitative Resistance in the Cereals written by Randall Jerome Wisser and published by . This book was released on 2006 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agronomy News written by and published by . This book was released on 1991 with total page 832 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sept.-Oct. issue includes list of theses and dissertations for U.S. and Canadian graduate degrees granted in crop science, soil science, and agronomic science during the previous academic year.
Download or read book Agrindex written by and published by . This book was released on 1995 with total page 1390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1990 with total page 1104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cereals written by Marcelo J. Carena and published by Springer Science & Business Media. This book was released on 2009-04-21 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Agriculture depends on improved cultivars, and cultivars are developed through proper plant breeding. Unfortunately, applied plant breeding programs that are focused on cereal commodity crops are under serious erosion because of lack of funding. This loss of public support affects breeding continuity, objectivity, and, perhaps equally important, the training of future plant breeders and the utilization and improvement of plant genetic resources currently available. Breeding programs should focus not only on short-term research goals but also on long-term genetic improvement of germplasm. The research products of breeding programs are important not only for food security but also for commodity-oriented public and private programs, especially in the fringes of crop production. Breeding strategies used for long-term selection are often neglected but the reality is that long-term research is needed for the success of short-term products. An excellent example is that genetically broad-based public germplasm has significantly been utilized and recycled by industry, producing billions of dollars for industry and farmers before intellectual property rights were available. Successful examples of breeding continuity have served the sustainable cereal crop production that we currently have. The fact that farmers rely on public and private breeding institutions for solving long-term challenges should influence policy makers to reverse this trend of reduced funding. Joint cooperation between industry and public institutions would be a good example to follow. The objective of this volume is to increase the utilization of useful genetic resources and increase awareness of the relative value and impact of plant breeding and biotechnology. That should lead to a more sustainable crop production and ultimately food security. Applied plant breeding will continue to be the foundation to which molecular markers are applied. Focusing useful molecular techniques on the right traits will build a strong linkage between genomics and plant breeding and lead to new and better cultivars. Therefore, more than ever there is a need for better communication and cooperation among scientists in the plant breeding and biotechnology areas. We have an opportunity to greatly enhance agricultural production by applying the results of this research to meet the growing demands for food security and environmental conservation. Ensuring strong applied plant breeding programs with successful application of molecular markers will be essential in ensuring such sustainable use of plant genetic resources.
Download or read book The Cereal Rusts Origins specificity structure and physiology written by William Rodgers Bushnell and published by . This book was released on 1984 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: Origins, specificity, structure, and physiology; Evolution at the center of origin; Taxonomy of the cereal rust fungi; Specificity; The formae speciales; Race specificity and methods of study; Genetics of the pathogen: host association; Histology and molecular biology of host: parasite; Virulence frequency dynamics of cereal rust fungi; The rust fungus; Controlled infection by Puccinia graminis f.sp. tritici under artificial conditions; Developmental ultrastructure of hyphae and spores; Development and physical of teliospores; Obligate parasitism and axenic culture; The host parsite interface; The rusted host; Effects of rust on plant development in relation to the translocation of inorganic and organic solutes.
