Download or read book Multi Location Evaluation of Agronomic Traits in Maize Hybrids written by Michael Cody McKee and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize (Zea mays L.) is one of the main crops grown in the United States. Genetic improvement over the last century has seen a shift from using open-pollinated varieties to single cross hybrids. This has resulted in major grain yield gains and improved management methodologies. However, there is still concern about reduced genetic diversity in elite corn germplasm and the potential effects this could have on future maize productivity in the presence of numerous abiotic and biotic pressures. One solution to this issue is the incorporation of exotic germplasm into existing maize improvement programs. This exotic material must be evaluated and characterized because too much or poorly matched exotic material can lead to reduced productivity. The use of multiple environments representative to the target improvement area is the best way to determine the true potential of certain material. The objectives of this research were to: i) estimate the responses of hybrids to aflatoxin and their agronomic performance across a range of environments under inoculation with Aspergillus flavus; ii) identify the hybrids within each group that exhibit the lowest levels of contamination; iii) analyze the relationship between agronomic performance and aflatoxin accumulation; and iv) determine how Genotype x Environment interactions affect these traits. Agronomic data was collected in ten Texas environments in 2005 for hybrids created from yellow, white, and Quality Protein Maize material that was crossed with one of two elite temperate inbred testers, LH195 or LH210. Response to aflatoxin was measured in eight of these environments. U.S. commercial hybrids were used as checks. Significant differences between hybrids were observed at different environments for different traits. Overall the experimental hybrids had lower aflatoxin accumulation than the commercial checks. They also yielded lower and had lower test weights and 1000 kernel weights. However, there were some hybrids that were competitive with the commercial checks for these agronomic traits. The incorporation of this material into established U.S. lines could be beneficial with regards to aflatoxin accumulation and kernel quality, which could ultimately translate to higher yields and crop quality. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148414

Download or read book GGE Biplot Analysis written by Weikai Yan and published by CRC Press. This book was released on 2002-08-28 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research data is expensive and precious, yet it is seldom fully utilized due to our ability of comprehension. Graphical display is desirable, if not absolutely necessary, for fully understanding large data sets with complex interconnectedness and interactions. The newly developed GGE biplot methodology is a superior approach to the graphical analys

Download or read book Developing Drought and Low N tolerant Maize written by G. O. Edmeades and published by CIMMYT. This book was released on 1996 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Incidence and intensity of drought and low N stresss in the tropics; Case studies strategies for crop production under drought and low n stresses in the tropics; Stress physology and identification of secondary traits; Physiology of low nitrogen stress; Breeding for tolerance to drought and low n stresses; General breeding strategies for stress tolerance; Progress in breeding drought tolerance; Progress in breeding low nitrogen tolerance; Experimental design and software.

Download or read book Genetics and Exploitation of Heterosis in Crops written by J. G. Coors and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explore the momentous contributions of hybrid crop varieties with worldwide experts. Topics include an overview, quantitative genetics, genetic diversity, biochemistry and molecular biology, methodologies, commercial strategies, and examples from numerous crops.

Download or read book Evaluation of Teosinte Genetic Diversity for Agronomic and Domestication Traits in Maize written by Avinash Karn and published by . This book was released on 2017 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize (Zea mays ssp. mays) is one of the most important crops in the world. Teosinte (Zea mays ssp. parviglumis) is the wild progenitor of maize and has greater genetic diversity than maize inbreds and landraces. Maize was domesticated from teosinte 9000 years ago, in central Mexico, and has been subjected to modern plant breeding over the past 100 years. In the recent years, extensive scientific breeding practices have led to remarkable yield increases in maize. However, domesticated and artificial genes have greatly reduced genetic diversity and cannot contribute to variation for agronomically important traits. Teosinte readily forms hybrids with maize and thus offers a unique pool of allelic diversity for maize improvement, yet limited genetic resources were available to efficiently evaluate and tap this diversity. To broaden resources for genetic diversity studies in maize, our lab previously developed over 900 near-isogenic introgression lines (NILs) from 10 teosinte accessions in the B73 background, and here we report the development of a new population, the Teosinte Synthetic (Teo-Syn). In order to understand the relationship between genetic diversity from teosinte and grain composition, we evaluated kernel starch, protein, and oil content, in the teosinte NILs. We found two starch, three protein and six oil QTL, which collectively explain 18%, 23% and 45% of the total variation, respectively. A range of strong allelic effects were identified relative to the B73 allele, supporting our hypothesis that teosinte harbors stronger alleles for kernel composition traits than maize. We found that some of the regions of the genome that control grain composition in our population were previously identified in maize, but we also found several new regions of the genome from teosinte that control grain composition. These teosinte alleles can be exploited for the improvement of kernel composition traits in modern maize germplasm. Ultimately, these novel regions of the teosinte genome can be mined for useful variation to improve corn for producers and consumers, as well as many industrial applications. In maize, common variants play a critical role to adapt to numerous large-scale environments; however, there are numerous rare alleles that may contribute to inbreeding depression or heterosis through complementation, or in complex quantitative traits such as yield, adaptation and kernel composition. It is important to understand the role of rare alleles in the maize genetic architecture in order to aid in the selection and development of future elite breeding lines. A new genetic resource, the Teosinte Synthetic (Teo-Syn), was developed by our lab by randomly mating backcrossed (BC1) progeny of 11 parviglumis accessions in the B73 background, yielding a population with the expected genetic ratio of ~25% teosinte and ~75% B73. We identified several significant QTLs for plant architecture, adaptation and kernel composition traits with a wide range of allelic effects. We further investigated if there is any statistical evidence for epistatic interactions in the Teo-Syn population, and found numerous interacting sites with larger and wider effects than additive effects. Maize plays a central role in the US agriculture and food production, as well as has the greatest molecular and phenotypic diversity than any crop species. My results from this study provide accumulated evidence for epistatic interactions influencing the genetic architecture of several plant architecture and composition traits. Findings from this study provide novel information that can be utilized by breeders and geneticist to accelerate the development of future elite maize germplasm as well as provide insight to efficiently predict hybrid performance.

Download or read book Quantitative Genetics in Maize Breeding written by Arnel R. Hallauer and published by Springer Science & Business Media. This book was released on 2010-09-28 with total page 669 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize is used in an endless list of products that are directly or indirectly related to human nutrition and food security. Maize is grown in producer farms, farmers depend on genetically improved cultivars, and maize breeders develop improved maize cultivars for farmers. Nikolai I. Vavilov defined plant breeding as plant evolution directed by man. Among crops, maize is one of the most successful examples for breeder-directed evolution. Maize is a cross-pollinated species with unique and separate male and female organs allowing techniques from both self and cross-pollinated crops to be utilized. As a consequence, a diverse set of breeding methods can be utilized for the development of various maize cultivar types for all economic conditions (e.g., improved populations, inbred lines, and their hybrids for different types of markets). Maize breeding is the science of maize cultivar development. Public investment in maize breeding from 1865 to 1996 was $3 billion (Crosbie et al., 2004) and the return on investment was $260 billion as a consequence of applied maize breeding, even without full understanding of the genetic basis of heterosis. The principles of quantitative genetics have been successfully applied by maize breeders worldwide to adapt and improve germplasm sources of cultivars for very simple traits (e.g. maize flowering) and very complex ones (e.g., grain yield). For instance, genomic efforts have isolated early-maturing genes and QTL for potential MAS but very simple and low cost phenotypic efforts have caused significant and fast genetic progress across genotypes moving elite tropical and late temperate maize northward with minimal investment. Quantitative genetics has allowed the integration of pre-breeding with cultivar development by characterizing populations genetically, adapting them to places never thought of (e.g., tropical to short-seasons), improving them by all sorts of intra- and inter-population recurrent selection methods, extracting lines with more probability of success, and exploiting inbreeding and heterosis. Quantitative genetics in maize breeding has improved the odds of developing outstanding maize cultivars from genetically broad based improved populations such as B73. The inbred-hybrid concept in maize was a public sector invention 100 years ago and it is still considered one of the greatest achievements in plant breeding. Maize hybrids grown by farmers today are still produced following this methodology and there is still no limit to genetic improvement when most genes are targeted in the breeding process. Heterotic effects are unique for each hybrid and exotic genetic materials (e.g., tropical, early maturing) carry useful alleles for complex traits not present in the B73 genome just sequenced while increasing the genetic diversity of U.S. hybrids. Breeding programs based on classical quantitative genetics and selection methods will be the basis for proving theoretical approaches on breeding plans based on molecular markers. Mating designs still offer large sample sizes when compared to QTL approaches and there is still a need to successful integration of these methods. There is a need to increase the genetic diversity of maize hybrids available in the market (e.g., there is a need to increase the number of early maturing testers in the northern U.S.). Public programs can still develop new and genetically diverse products not available in industry. However, public U.S. maize breeding programs have either been discontinued or are eroding because of decreasing state and federal funding toward basic science. Future significant genetic gains in maize are dependent on the incorporation of useful and unique genetic diversity not available in industry (e.g., NDSU EarlyGEM lines). The integration of pre-breeding methods with cultivar development should enhance future breeding efforts to maintain active public breeding programs not only adapting and improving genetically broad-based germplasm but also developing unique products and training the next generation of maize breeders producing research dissertations directly linked to breeding programs. This is especially important in areas where commercial hybrids are not locally bred. More than ever public and private institutions are encouraged to cooperate in order to share breeding rights, research goals, winter nurseries, managed stress environments, and latest technology for the benefit of producing the best possible hybrids for farmers with the least cost. We have the opportunity to link both classical and modern technology for the benefit of breeding in close cooperation with industry without the need for investing in academic labs and time (e.g., industry labs take a week vs months/years in academic labs for the same work). This volume, as part of the Handbook of Plant Breeding series, aims to increase awareness of the relative value and impact of maize breeding for food, feed, and fuel security. Without breeding programs continuously developing improved germplasm, no technology can develop improved cultivars. Quantitative Genetics in Maize Breeding presents principles and data that can be applied to maximize genetic improvement of germplasm and develop superior genotypes in different crops. The topics included should be of interest of graduate students and breeders conducting research not only on breeding and selection methods but also developing pure lines and hybrid cultivars in crop species. This volume is a unique and permanent contribution to breeders, geneticists, students, policy makers, and land-grant institutions still promoting quality research in applied plant breeding as opposed to promoting grant monies and indirect costs at any short-term cost. The book is dedicated to those who envision the development of the next generation of cultivars with less need of water and inputs, with better nutrition; and with higher percentages of exotic germplasm as well as those that pursue independent research goals before searching for funding. Scientists are encouraged to use all possible breeding methodologies available (e.g., transgenics, classical breeding, MAS, and all possible combinations could be used with specific sound long and short-term goals on mind) once germplasm is chosen making wise decisions with proven and scientifically sound technologies for assisting current breeding efforts depending on the particular trait under selection. Arnel R. Hallauer is C. F. Curtiss Distinguished Professor in Agriculture (Emeritus) at Iowa State University (ISU). Dr. Hallauer has led maize-breeding research for mid-season maturity at ISU since 1958. His work has had a worldwide impact on plant-breeding programs, industry, and students and was named a member of the National Academy of Sciences. Hallauer is a native of Kansas, USA. José B. Miranda Filho is full-professor in the Department of Genetics, Escola Superior de Agricultura Luiz de Queiroz - University of São Paulo located at Piracicaba, Brazil. His research interests have emphasized development of quantitative genetic theory and its application to maize breeding. Miranda Filho is native of Pirassununga, São Paulo, Brazil. M.J. Carena is professor of plant sciences at North Dakota State University (NDSU). Dr. Carena has led maize-breeding research for short-season maturity at NDSU since 1999. This program is currently one the of the few public U.S. programs left integrating pre-breeding with cultivar development and training in applied maize breeding. He teaches Quantitative Genetics and Crop Breeding Techniques at NDSU. Carena is a native of Buenos Aires, Argentina. http://www.ag.ndsu.nodak.edu/plantsci/faculty/Carena.htm

Download or read book Genetically Engineered Crops written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2017-01-28 with total page 607 pages. Available in PDF, EPUB and Kindle. Book excerpt: Genetically engineered (GE) crops were first introduced commercially in the 1990s. After two decades of production, some groups and individuals remain critical of the technology based on their concerns about possible adverse effects on human health, the environment, and ethical considerations. At the same time, others are concerned that the technology is not reaching its potential to improve human health and the environment because of stringent regulations and reduced public funding to develop products offering more benefits to society. While the debate about these and other questions related to the genetic engineering techniques of the first 20 years goes on, emerging genetic-engineering technologies are adding new complexities to the conversation. Genetically Engineered Crops builds on previous related Academies reports published between 1987 and 2010 by undertaking a retrospective examination of the purported positive and adverse effects of GE crops and to anticipate what emerging genetic-engineering technologies hold for the future. This report indicates where there are uncertainties about the economic, agronomic, health, safety, or other impacts of GE crops and food, and makes recommendations to fill gaps in safety assessments, increase regulatory clarity, and improve innovations in and access to GE technology.

Download or read book Grain Yield and Other Agronomic Characteristics of Selected Maize Hybrids Under Irrigation in Cyprus written by C. M. Josephides and published by . This book was released on 1990 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Breeding for Quantitative Traits in Plants written by Rex Novero Bernardo and published by . This book was released on 2019 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Argentine Maize Hybrids and Exotic X Temperate Testcrosses Across Environments written by Brett A. Ochs and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize (Zea mays L.) is grown in a wide range of environments and altitudes worldwide. Maize has transitioned from open pollinated varieties to single cross hybrids over the last century. While maize production and genetic gain has increased, genetic diversity among U.S. maize hybrids has narrowed. Problems, such as insect pressure, diseases, and mycotoxins, present obstacles for breeders. One approach is to use exotic germplasm in breeding programs to provide useful, novel alleles for productivity, grain quality, and disease resistance. Little exotic germplasm has been used, because of lack of agronomic adaptation and problems with lodging, earliness, and tall plants in more temperate areas. Using exotic elite materials and evaluating them in targeted regions might increase success. Objectives of this research were: to characterize and evaluate agronomic adaptation and performance of Argentine commercial hybrids in the U.S., to evaluate semi-exotic testcrosses developed from semi adapted 100% tropical lines and elite U.S. inbred LH195, and to estimate response to aflatoxin contamination of Argentine hybrids and semi-exotic testcrosses under inoculation with Aspergillus flavus. Agronomic data was collected during 2004 in eleven Texas environments for Argentine hybrids, and eight Texas environments for semi-exotic testcrosses. Response to aflatoxin was measured in three southern Texas environments. U.S. commercial hybrids were used as checks. Significant differences among hybrids were observed for most environments and traits. In general, Argentine hybrids yielded lower, had lower 1000 kernel weights, and greater test weights than U.S. hybrids. Hybrids AX889, AX882MG, and AX890MG were competitive with U.S. hybrids for grain yield and were stable across environments. Semi-exotic testcrosses had similar lodging and grain moisture percentages, heavier test weights and competitive grain yields compared with U.S. hybrids. Hybrid TX-LAMA2002-9-2-B/lH195 had the highest overall grain yield mean for semi-exotic testcrosses and yielded better than two U.S. hybrids. Argentine hybrids had lower aflatoxin concentration than U.S. hybrids; several hybrids had less than 50 ng g−1 aflatoxin. Semi-exotic testcrosses had reduced aflatoxin compared to U.S. hybrids, with several hybrids under 35 ng g−1. These elite, exotic materials show promise for breeding programs, with competitiveness for grain yield, kernel traits, and reduced aflatoxin levels.

Download or read book Doubled Haploid Production in Crop Plants written by M. Maluszynski and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of doubled haploids has become a necessary tool in advanced plant breeding institutes and commercial companies for breeding many crop species. However, the development of new, more efficient and cheaper large scale production protocols has meant that doubled haploids are also recently being applied in less advanced breeding programmes. This Manual was prepared to stimulate the wider use of this technology for speeding and opening up new breeding possibilities for many crops including some woody tree species. Since the construction of genetic maps using molecular markers requires the development of segregating doubled haploid populations in numerous crop species, we hope that this Manual will also help molecular biologists in establishing such mapping populations. For many years, both the Food and Agriculture Organization of the United Nations (FAO) and the International Atomic Energy Agency (IAEA) have supported and coordinated research that focuses on development of more efficient doubled haploid production methods and their applications in breeding of new varieties and basic research through their Plant Breeding and Genetics Section of the Joint F AO/IAEA Division of Nuclear Techniques in Food and Agriculture. The first F AO/IAEA scientific network (Coordinated Research Programme - CRP) dealing with doubled haploids was initiated by the Plant Breeding and Genetics Section in 1986.

Download or read book Breeding for drought and nitrogen stress tolerance in maize From theory to practice written by M. Bänzinger and published by CIMMYT. This book was released on 2000 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction - why breed for drought and low N tolerance?; Conceptual framework - breeding; Conventional approaches to improving the drought and low N tolerance of maize; Conventional approaches challenged; The challenge of breeding for drought and low N tolerance; Maize under drought and low N stress; Conceptual framework - physiology; Water and the maize plant; Nitrogen and the maize plant; Maize under drought and low N stress - consequences for breeding; Stress management; Drought; Low N stress; Statistical designs and layout of experiments; Increasing the number of replicates; Improved statistical designs; Field layout; Border effects from alleys; Secondary traits; Why use secondary traits?; How do we decide on the value of secondary traits in a drought or low N breeding program?; Secondary traits that help to identify drought tolerance; Secondary traits that help to identify low N tolerance: Selection indices - Combining information on secondary traits with grain yield; Combining information from various experiments; Breeding strategies; Choice of germplasm; Breeding schemes; Biotechnology: potential and constraints for improving drought and low N tolerance; The role of the farmer in selection; What is farmer participatory research and why is it important?; What is new about farmer participatory research?; Participatory methodologies.

Download or read book Cereal Grains written by Aakash K. Goyal and published by BoD – Books on Demand. This book was released on 2021-12-22 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past 50 years, cereals such as maize, rice, wheat, sorghum, and barley have emerged as rapidly evolving crops because of new technologies and advances in agronomy, breeding, biotechnology, genetics, and so on. Population growth and climate change have led to new challenges, among which are feeding the growing global population and mitigating adverse effects on the environment. One way to deal with these issues is through sustainable cereal production. This book discusses ways to achieve sustainable production of cereals via agronomy, breeding, transcriptomics, proteomics, and metabolomics. Chapters review research, examine challenges, and present prospects in the field. This volume is an excellent resource for students, researchers, and scientists interested and working in the area of sustainable crop production.

Download or read book Maize Improvement written by Shabir Hussain Wani and published by Springer Nature. This book was released on 2023-03-10 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize is one of the most generally grown cereal crops at global level, followed by wheat and rice. Maize is the major crop in China both in terms of yield and acreage. In 2012, worldwide maize production was about 840 million tons. Maize has long been a staple food of most of the global population (particularly in South America and Africa) and a key nutrient resource for animal feed and for food industrial materials. Maize belts vary from the latitude 58° north to the latitude 40° south, and maize ripens every month of the year. Abiotic and biotic stresses are common in maize belts worldwide. Abiotic stresses (chiefly drought, salinity, and extreme temperatures), together with biotic stresses (primarily fungi, viruses, and pests), negatively affect maize growth, development, production and productivity. In the recent past, intense droughts, waterlogging, and extreme temperatures have relentlessly affected maize growth and yield. In China, 60% of the maize planting area is prone to drought, and the resultant yield loss is 20%–30% per year; in India, 25%–30% of the maize yield is lost as a result of waterlogging each year. The biotic stresses on maize are chiefly pathogens (fungal, bacterial, and viral), and the consequential syndromes, like ear/stalk rot, rough dwarf disease, and northern leaf blight, are widespread and result in grave damage. Roughly 10% of the global maize yield is lost each year as a result of biotic stresses. For example, the European corn borer [ECB, Ostrinianubilalis (Hübner)] causes yield losses of up to 2000 million dollars annually in the USA alone in the northern regions of China, the maize yield loss reaches 50% during years when maize badly affected by northern leaf blight. In addition, abiotic and biotic stresses time and again are present at the same time and rigorously influence maize production. To fulfill requirements of each maize-growing situation and to tackle the above mentions stresses in an effective way sensibly designed multidisciplinary strategy for developing suitable varieties for each of these stresses has been attempted during the last decade. Genomics is a field of supreme significance for elucidating the genetic architecture of complex quantitative traits and characterizing germplasm collections to achieve precise and specific manipulation of desirable alleles/genes. Advances in genotyping technologies and high throughput phenomics approaches have resulted in accelerated crop improvement like genomic selection, speed breeding, particularly in maize. Molecular breeding tools like collaborating all omics, has led to the development of maize genotypes having higher yields, improved quality and resilience to biotic and abiotic stresses. Through this book, we bring into one volume the various important aspects of maize improvement and the recent technological advances in development of maize genotypes with high yield, high quality and resilience to biotic and abiotic stresses

Download or read book An Introduction to Genetic Statistics written by Oscar Kempthorne and published by Wiley-Blackwell. This book was released on 1957 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: Elementary probability; Random mating populations; Elementary selection problems; The elementary stochastic theory of genetic populations; Inbreeding; The generation matrix theory of inbreeding; Tests of genetic hypotheses; The estimation of genetic parameters; The planning of experiments; Statistical problems in human genetics; The analysis of variation; The partition of variance; Multiple regression, correlation and adjustment of data, and path analysis; Inheritance of quantitative characters in a random mating population; Non-random mating deploid populations with one locus segregating; Correlation between relatives under inbreeding with one locus segregating; One-locus polyploid populations; Diploid populations with arbitrary number of segregating loci and arbitrary epistacy; Inbreeding with a arbitrary diploid population; Population derived from inbred lines; Infinitesimal equilibrium theory of assortative mating; Selection for quantitative characters.

Download or read book Genetic Data Analysis for Plant and Animal Breeding written by Fikret Isik and published by Springer. This book was released on 2017-09-09 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book fills the gap between textbooks of quantitative genetic theory, and software manuals that provide details on analytical methods but little context or perspective on which methods may be most appropriate for a particular application. Accordingly this book is composed of two sections. The first section (Chapters 1 to 8) covers topics of classical phenotypic data analysis for prediction of breeding values in animal and plant breeding programs. In the second section (Chapters 9 to 13) we provide the concept and overall review of available tools for using DNA markers for predictions of genetic merits in breeding populations. With advances in DNA sequencing technologies, genomic data, especially single nucleotide polymorphism (SNP) markers, have become available for animal and plant breeding programs in recent years. Analysis of DNA markers for prediction of genetic merit is a relatively new and active research area. The algorithms and software to implement these algorithms are changing rapidly. This section represents state-of-the-art knowledge on the tools and technologies available for genetic analysis of plants and animals. However, readers should be aware that the methods or statistical packages covered here may not be available or they might be out of date in a few years. Ultimately the book is intended for professional breeders interested in utilizing these tools and approaches in their breeding programs. Lastly, we anticipate the usage of this volume for advanced level graduate courses in agricultural and breeding courses.

Download or read book Plant Adaptation and Crop Improvement written by Mark Cooper and published by IRRI. This book was released on 1996 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of crop improvement; Analysis of genotype by environment interactions; Interpretation of genotype by environment interactions; Integrated approaches to plant improvement; Synthesis of strategies for crop improvement.