Download or read book A Historical Evaluation of High Molecular Weight Glutenins and the Dwarfing Rht Gene in Triticum Aestivum in Selected Genotypes Grown in the United States written by Colleen Roseborough and published by . This book was released on 2015 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wheat (Triticum aestivum) is an important crop worldwide, however, in recent years concerns have been raised regarding two health issues, celiac disease and gluten sensitivity, and their relationship to wheat consumption. This increase has led to questions regarding potential changes over time in the composition of gluten (glutenin and gliadin) in wheat, especially after incorporation of the reduced height alleles (Rht-D1b and Rht-B1b) to increase wheat productivity. Questions raised include: 1) Have there been changes in the frequencies of glutenin alleles in hard or soft-grained wheat since the incorporation of the Rht alleles and 2) Are potential changes in wheat gluten a result of breeding for increased dough strength? To answer these questions, 124 top production acreage cultivars from the Pacific Northwest (PNW) and elsewhere across the United States were collected. All but one cultivar (19th century) were developed and grown in the 20th and 21st centuries. PNW soft-winter wheat cultivars were included as there has been systematic selection pressure applied to decrease dough strength in this wheat class whereas other regions have selected for increased dough strength. Plants of each cultivar were grown under greenhouse conditions in a completely randomized design with four replications. For Rht testing, DNA was collected from plants at the two leaf stage. Two Kompetitive Allele Specific PCR (KASP) single nucleotide polymorphism (SNP) assays were performed to detect the dwarfing mutant alleles (Rht-D1b or Rht-B1b) or wild-type non-dwarfing alleles (Rht-D1a or Rht-B1a). The first assay was for Rht-B1 located on chromosome 4B. The second assay was for Rht-D1, which is located on chromosome 4D. To determine the composition of high molecular weight glutenins, grain was harvested at maturity and micro fluidic capillary electrophoresis was used. Analysis showed that there had been a shift in glutenin subunits after 1999 in both hard and soft wheat cultivars. No significant change was found at the Glu-A1 and Glu-B1 loci in hard wheat. However, at the Glu-A1 locus in soft wheat, subunit Ax1 decreased in frequency over time while the null allele increased over time. At the Glu-B1 locus, subunit Bx7 showed an increase over time. After 1999, the Glu-D1 locus in hard wheat contained the Dx5+Dy10 combination at a higher frequency than previously observed. For soft wheat the Dx2+Dy12 subunit combination was the only combination present. KASP assays showed that the dwarfing alleles of the Rht gene were in only one cultivar in the 1950's, however, by the 1960's half of the PNW cultivars contained a dwarfing Rht gene. By the year 2000 all PNW cultivars tested contained a dwarfing gene. Cultivars from other states had a slower incorporation of this gene; as of the year 2000 dwarfing alleles were found at 73% frequency. With the introduction of the gene, glutenin subunit patterns did not shift from prior years.
Download or read book The Evolution of Hexaploid Wheat written by Robert Hans Erich Blatter and published by . This book was released on 2002 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physiological Molecular and Genetic Perspectives of Wheat Improvement written by Shabir H Wani and published by Springer Nature. This book was released on 2020-12-17 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: World population is growing at an alarming rate and may exceed 9.7 billion by 2050, whereas agricultural productivity has been negatively affected due to yield limiting factors such as biotic and abiotic stresses as a result of global climate change. Wheat is a staple crop for ~20% of the world population and its yield needs be augmented correspondingly in order to satisfy the demands of our increasing world population. “Green revolution”, the introduction of semi-dwarf, high yielding wheat varieties along with improved agronomic management practices, gave rise to a substantial increase in wheat production and self-sufficiency in developing countries that include Mexico, India and other south Asian countries. Since the late 1980’s, however, wheat yield is at a standoff with little fluctuation. The current trend is thus insufficient to meet the demands of an increasing world population. Therefore, while conventional breeding has had a great impact on wheat yield, with climate change becoming a reality, newer molecular breeding and management tools are needed to meet the goal of improving wheat yield for the future. With the advance in our understanding of the wheat genome and more importantly, the role of environmental interactions on productivity, the idea of genomic selection has been proposed to select for multi-genic quantitative traits early in the breeding cycle. Accordingly genomic selection may remodel wheat breeding with gain that is predicted to be 3 to 5 times that of crossbreeding. Phenomics (high-throughput phenotyping) is another fairly recent advancement using contemporary sensors for wheat germplasm screening and as a selection tool. Lastly, CRISPR/Cas9 ribonucleoprotein mediated genome editing technology has been successfully utilized for efficient and specific genome editing of hexaploid bread wheat. In summary, there has been exciting progresses in the development of non-GM wheat plants resistant to biotic and abiotic stress and/or wheat with improved nutritional quality. We believe it is important to highlight these novel research accomplishments for a broader audience, with the hope that our readers will ultimately adopt these powerful technologies for crops improvement in order to meet the demands of an expanding world population.
Download or read book Proceedings written by and published by . This book was released on 1998 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heterologous Expression of Wheat High Molecular Weight Glutenin Subunit Genes written by Olin D. Anderson and published by . This book was released on 1993 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gliadin and Glutenin written by Colin W. Wrigley and published by . This book was released on 2006 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph provides a review of the knowledge that makes possible the intelligent tailoring of wheat proteins to provide for specific dough requirements. It emphasizes the combined roles of the gliadin and glutenin proteins in providing the balance that gives wheat gluten its unique rheological properties. The book gives a major update on the composition and functional properties of the gluten proteins, but it also includes introductory chapters to "set the scene" for young scientists and anyone new to this area of food science.
Download or read book Genetic and Genomic Tools for Improving End use Quality in Wheat written by Emily Elizabeth Delorean and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wheat accounts for 20% of daily caloric intake of the world population and has one of the widest cultivation distributions of any crop. With increasing demand for both quantity and quality, wheat yields must increase while also maintaining acceptable end-use quality. However, measuring end-use quality is complex, requires large volumes grain and significant effort. The overarching goal of this dissertation research was to develop genetic and genomic tools to facilitate breeding for end-use quality in wheat. Building on initial work with genomic prediction of wheat quality, we continued application of genomic prediction models to the International Maize and Wheat Improvement Center (CIMMYT) wheat breeding program. For practical application in the breeding program to advance selection, we focused on forward prediction in each cycle of the bread wheat program. Models were built on 12 years of past data including over 18,000 entries with quality data. Predictions for 10,000 yield trial lines were generated each year for selection, with forward prediction accuracies of 0.40 to 0.73, and approached heritability. This is one of the largest scale applications of genomic selection. We also studied the interaction of climate change and the important quality genes, high-molecular weight glutenins (HMW-GS) and low-molecular weight glutenins (HMW-GS). A diverse panel of 54 CIMMYT wheat varieties were grown in 2 levels of drought stress, heat stress and optimal growth conditions. Quality traits, HMW-GS and LMW-GS alleles were measured. We fit a mixed linear model for each quality trait with HMW-GS, LMW-GS, environment, and the interactions of those as predictors. Overall, the superior glutenin alleles either maintained or increased quality in stressful environments. This work confirmed that superior alleles should always be selected for, regardless of target environment. To increase the genetic diversity for wheat quality, we analyzed Glu-D1 gene diversity on the wheat D genome donor, Aegilops tauschii. We constructed Glu-D1 molecular haplotypes from sequence data of 234 Ae. tauschii accessions and found 15 subclades and over 45 haplotypes, representing immense gene diversity. We found evidence that the 5+10 allele originated from a newly described Lineage 3 of Ae. tauschii, further supporting that this unique lineage contributed to modern bread wheat. We also observed rare recombinant haplotypes between the x and y subunits of any HMW-GS locus. This work will facilitate incorporation of Ae. tauschii Glu-D1 alleles into modern wheat. Given that certain HMW-GS alleles are highly desirable, we set out to develop a high-throughput, high resolution genotyping method for HMW-GS alleles that would fit within genotyping already done for genomic prediction models. This 'sequence based genotyping' approach uses diagnostic k-mers developed to predict alleles in skim-sequenced breeding material. Prediction accuracies for Glu-D1 and Glu-A1 were very good, but lower for the Glu-B1 alleles where many alleles are highly related. Overall, SBG offers a high throughput method to call alleles from existing data. These genetic and genomic tools developed and implemented for end-use quality selection in wheat offer promising resources for continued improvement of both yield and quality in wheat breeding.
Download or read book Dwarfing Genes in Spring Wheat written by Amber Marie Robbins and published by . This book was released on 2009 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rht-B1b and Rht-D1b (formerly Rht1 and Rht2) dwarfing genes have been used extensively since the Green Revolution to reduce height and increase yield in hexaploid wheat (Triticum aestivum L.). They have been used in the development of hundreds of modern cultivars. Semi-dwarf wheat varieties containing these GA-insensitive dwarfing genes generally yield more grain than their tall Rht-B1a and Rht-D1a (formerly rht1 and rht2) counterparts. However, Rht-B1b and Rht-D1b are better adapted to high-input environments and can reduce plant performance under adverse conditions such as heat or drought stress. In such environments, Rht8, a GA-sensitive dwarfing gene, could prove beneficial. This study aimed to assess agronomic performance of Rht8 compared to Rht-B1b and Rht-D1b using near-isogenic lines of the six possible genotypes (Rht-B1b, Rht-B1a, Rht-D1b, Rht-D1a, Rht8, and rht8) in four different spring wheat backgrounds. Field trials were conducted during the 2008 and 2009 growing seasons in Bozeman and Kalispell, MT. Traits measured included plant height, coleoptile length, stem solidness, days to heading, yield, flag leaf characteristics, harvest index, and others. Measurements were taken from field trials except coleoptile length, which was grown in a temperature and light controlled growth chamber. Rht genotype had a significant effect on plant height, coleoptile length, and yield. Height reductions of 20.5%, 22.4%, and 10.1% were observed for Rht-B1b, Rht-D1b, and Rht8, respectively. Rht8 showed no significant effect on coleoptile length, while Rht-B1b and Rht-D1b exhibited reductions in coleoptile length of 21.3% and 22.8%. Rht-B1b and Rht-D1b both showed a 6.1% and 14.1%. increase in yield potential. In contrast, Rht8 showed a yield decrease of 5.3%. Of most interest to plant breeders are those traits that effect yield. Yield is a complex, multi-genic trait that is affected by many plant characteristics and environmental factors. Because of the quantitative nature of yield, it is impacted by not only the presence of dwarfing genes, but also genetic background and environmental variables. This study suggests that Rht-B1b and Rht-D1b are superior, in terms of yield potential, to Rht8. However, additional evaluation of Rht8 in differing environments is needed to elucidate its precise effects on yield and other agronomic traits.
Download or read book Investigations of Gluten Proteins from Functional and Historical Perspective written by Ying Zhang and published by . This book was released on 2015 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wheat (Triticum aestivum) is one of the world's major staple food crops, with flour produced from starchy endosperm being used for breads, cakes, noodles and various other wheat-based foods. The unique bread making properties of wheat are primarily attributed to its gluten-forming storage proteins: gliadins and glutenins. This study investigated the gluten proteins from functional and historical perspectives. The first study examined primarily the functional role of gluten proteins in the outcomes of the standard Falling Number (FN) test. The FN test is used in the grain trade to screen delivered wheat for the presence of pre-harvest sprouting by indirectly measuring [alpha]-amylase through it effects on the physical consistency of a cooked flour-water suspension. Grain protein content (GPC) has been implicated as a potential modifier of FN independent of [alpha]-amylase or sprout status. In the gluten functionality study, we proposed a protein unfolding and crosslinking model, and hypothesized that gluten proteins with higher molecular weight distributions (MWD) would heatset faster, tightly cover starch granules, restrict water entry, and slow their disintegration. In contrast to our hypothesis, our results showed that samples with lower MWD had faster heatset times than samples with higher MWD according to a controlled heating test. We also hypothesize that increased granularity of hard wheat flour reduces the surface area to volume ratio so the starch granules embedded in the particles need more time to hydrate or swell. However, our results indicated that natural variations in flour particle size from a standard grinding procedure that used a 0.8 mm screen had no impact on FN. The second study looked at potential changes in gluten proteins in a historical set of wheat varieties spanning more than 110 years of production. The wheats were in two sets: soft wheats where there has been no systematic selection for increased dough strength in breeding programs, and hard wheats where there has been a concerted effort to increase overall dough strength over the last century. The sample sets also covered the eras before and after the introduction of the semi-dwarf wheats to the USA. The reason for this investigation is related to the circumstance that wheat is the cause of celiac disease (CD) and is implcated in the disputed condition, non-celiac gluten sensitivity (NCGS). Recently, diagnoses of CD at least have increased and there are suggestions that changes in gluten proteins in the modern era are responsible. Since it is primarily gliadins that trigger CD, it was considered worth investigating whether or not there have been any changes in the composition of gliadins over the last century. Sixty-two soft and 61 hard U.S. high production wheat varieties from 1900 to the present (with one from 1800) were collected and analyzed by RP-HPLC. These varieties were investigated to begin to answer whether wheat breeding for higher dough strength, or the incorporation of dwarfing alleles after the 1960s, was associated with observable changes in gliadin composition. ANOVA showed that there was no significant difference between soft and hard wheats in the relative abundance of [alpha]/[beta]-gliadins. However, there were significant differences between hard and soft wheats in the relative abundance of [omega]- and [gamma]-gliadins. ANOVA also showed that there was no significant difference between tall and dwarf wheats in the relative abundance of any of the three gliadin fractions. The ANOVA results suggested that deliberate breeding for dough strength, as illustrated by the hard versus soft wheat contrast, had not systematically changed the relative abundance of [alpha]/[beta]-gliadins across the last 110 years, but had altered the relative abundance of the other two fractions. ANOVA results indicated no change in proportions of the three gliadin fractions after deployment of the dwarfing alleles suggesting the tall to dwarf change was independent of gluten composition. Second order polynomial regression analyses showed that the relative abundance of [alpha]/[beta]-gliadins increased until around 1960 then decreased. The changes were more noticeable in the hard wheats. The converse was observed for [gamma]-gliadins. This stepwise change questioned the association between CD increase and breeding for increased dough strength in hard wheats, since the relative abundance of [alpha]/[beta]-gliadins did not keep going up, and [alpha]-gliadin is considered the major trigger force for CD initiation. In contrast, linear correlation analyses with each of 700, three second long fractions of the RP-HPLC chromatograms suggested that most changes were related to the soft wheat population. The discrepancy between the regression analyses of the three major fractions and the 700 small fractions may be related to the use of linear correlations in the latter when some relationships were clearly non-linear. Overall, our results did not fully support speculations that there have been profound changes in gluten composition related to the dwarfing alleles or selection for increased dough strength in hard wheats.
Download or read book Handbook of Plant Nutrition written by Allen V. Barker and published by CRC Press. This book was released on 2016-04-19 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt: The burgeoning demand on the world food supply, coupled with concern over the use of chemical fertilizers, has led to an accelerated interest in the practice of precision agriculture. This practice involves the careful control and monitoring of plant nutrition to maximize the rate of growth and yield of crops, as well as their nutritional value.
Download or read book Genetic and Genomic Resources of Grain Legume Improvement written by Mohar Singh and published by Newnes. This book was released on 2013-07-18 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grain legumes, including common-bean, chickpea, pigeonpea, pea, cowpea, lentil and others, form important constituents of global diets, both vegetarian and non-vegetarian. Despite this significant role, global production has increased only marginally in the past 50 years. The slow production growth, along with a rising human population and improved buying capacity has substantially reduced the per capita availability of food legumes. Changes in environmental climate have also had significant impact on production, creating a need to identify stable donors among genetic resources for environmentally robust genes and designing crops resilient to climate change. Genetic and Genomic Resources of Grain Legume Improvement is the first book to bring together the latest resources in plant genetics and genomics to facilitate the identification of specific germplasm, trait mapping and allele mining to more effectively develop biotic and abiotic-stress-resistant grains. This book will be an invaluable resource for researchers, crop biologists and students working with crop development. - Explores origin, distribution and diversity of grain legumes - Presents information on germplasm collection, evaluation and maintenance - Offers insight into pre-breeding/germplasm enhancement efforts - Integrates genomic and genetic resources in crop improvement - Internationally contributed work
Download or read book Durum Wheat Breeding written by Conxita Royo and published by CRC Press. This book was released on 2005-11-07 with total page 571 pages. Available in PDF, EPUB and Kindle. Book excerpt: Is your knowledge about this important grain crop up to date? This comprehensive two-volume resource reviews the latest advances in scientific and technical knowledge for durum wheat breeding. With a scope of coverage that includes genetics and molecular biology, plant and crop physiology, and breeding strategies and methodology, Dur
Download or read book Guide to Bread Wheat Breeding at CIMMYT written by Maarten van Ginkel and published by CIMMYT. This book was released on 1998 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Official Grain Standards of the United States written by United States. Agricultural Marketing Service. Grain Division and published by . This book was released on 1949 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nutrient Use Efficiency in Plants written by Malcolm J. Hawkesford and published by Springer. This book was released on 2014-11-14 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nutrient Use Efficiency in Plants: Concepts and Approaches is the ninth volume in the Plant Ecophysiology series. It presents a broad overview of topics related to improvement of nutrient use efficiency of crops. Nutrient use efficiency (NUE) is a measure of how well plants use the available mineral nutrients. It can be defined as yield (biomass) per unit input (fertilizer, nutrient content). NUE is a complex trait: it depends on the ability to take up the nutrients from the soil, but also on transport, storage, mobilization, usage within the plant, and even on the environment. NUE is of particular interest as a major target for crop improvement. Improvement of NUE is an essential pre-requisite for expansion of crop production into marginal lands with low nutrient availability but also a way to reduce use of inorganic fertilizer.
Download or read book Bread Wheat written by Food and Agriculture Organization of the United Nations and published by Food & Agriculture Organization of the UN (FAO). This book was released on 2002 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wheat is the most widely grown cereal crop in the world, with an ever increasing demand. It plays a fundamental role in food security, and a major challenge is to meet the additional requirements with new cultivars and improved cropping technologies. This book covers information from a number of international experts on the current status of research on wheat improvement and production (wheat breeding programs and genetics), as well as on other aspects (including wheat diseases), from its evolutionary origins to seed production technologies. [from the FAO website]
Download or read book Wheat written by W. Bushuk and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wheat provides over 20% of the calories for the world population of 5. 3 billion persons. It is widely grown in five of the six continents. It is a highly versatile food product in that it can be stored safely for long periods of time and transported in bulk over long distances. In relative terms, it is reasonably priced; over the past quarter century, the inflation-adjusted price of wheat has been declining. Modern milling and baking technology required for the transformation of wheat grain into consumable baked products is available or accessible in all countries of the world. For these reasons, and because Canada is one of world's leading wheat producing countries, it seemed appropriate to include a major symposium on wheat in the scientific and technical program of the 8th World Congress of Food Science and Technology held in Toronto, Canada during September 29-0ctober 4, 1992. In selecting the topics for the symposium on wheat, we attempted to cover a full range of subjects including economics and marketing, nutrition, grading, processing, constituent chemistry and functionality, biote- nology, and safety of genetically modified wheat varieties. The major focus was on common hard (bread) wheats; separate papers were devoted to the unique characteristics and technological properties of common soft (biscuit) and durum (pasta) wheats. Each paper was presented by an acknowledged international expert. This book provides a more permanent record of the papers presented at the symposium.
