Download or read book Natural Selection for Adaptation in Maize at High Plant Density written by William Sylvester Niebur and published by . This book was released on 1983 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In the Light of Evolution written by National Academy of Sciences and published by . This book was released on 2007 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Arthur M. Sackler Colloquia of the National Academy of Sciences address scientific topics of broad and current interest, cutting across the boundaries of traditional disciplines. Each year, four or five such colloquia are scheduled, typically two days in length and international in scope. Colloquia are organized by a member of the Academy, often with the assistance of an organizing committee, and feature presentations by leading scientists in the field and discussions with a hundred or more researchers with an interest in the topic. Colloquia presentations are recorded and posted on the National Academy of Sciences Sackler colloquia website and published on CD-ROM. These Colloquia are made possible by a generous gift from Mrs. Jill Sackler, in memory of her husband, Arthur M. Sackler.

Download or read book Direct and Correlated Response to Recurrent Selection for Grain Yield in Maize Breeding Populations written by M.A.B. Fakorede and published by . This book was released on 1977 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dr. G. F. Sprague initiated recurrent selection programs during the 1940' and 1950' to improve the grain-yield performance of several maize (Zea mays L.) population at the Iowa Agriculture and Home Economics Experiments Station. Seven cycles of reciprocal recurrent selections (RRS) in Iowa Stiff Stalk Synthetic (BSSS) and Iowa Corn Borer Synthetic #1 (BSCB1), and six cycles of recurrent half-sib selection (HS) in the open-pollinated variety 'Alph'(i.e., BS12) have been completed. Inbred B14 was the tester in the HS program. My objectives were to (1) evaluate progress that resulted from the RRS and HS programs and (2) evaluate changes in several other traits associated with recurrent selection for grain yield. I evaluated the CO x CO, C5, and C7 x C7 of the RRS program, and CO and C6 of the HS program, each testcrossed to B14A. Estimated gain from seven cycles of RRS was 2.06 q/ha (or 5.21%) per cycle and observed difference in mean yield between CO and C6 of the program was 2.25 q/ha (or 6.00%) per cycle. Improved hybrids outyield their unimproved counterparts at all levels of nitrogen (0, 90, 180, and 270 kg N/ha) and plant density (39,000; 59,300; 79,000; and 98,800 plants/ha) investigated. Each hybrid displayed a positive, curvilinear response to nitrogen and a negative, linear response to plant density. Stability and adaptation-reaction analysis revealed that improved hybrids consistently demonstrated greater adaptation to high-nitrogen environments, but their unimproved counterparts did not take (...).

Download or read book The Maize Genome written by Jeffrey Bennetzen and published by Springer. This book was released on 2018-11-24 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses advances in our understanding of the structure and function of the maize genome since publication of the original B73 reference genome in 2009, and the progress in translating this knowledge into basic biology and trait improvement. Maize is an extremely important crop, providing a large proportion of the world’s human caloric intake and animal feed, and serving as a model species for basic and applied research. The exceptionally high level of genetic diversity within maize presents opportunities and challenges in all aspects of maize genetics, from sequencing and genotyping to linking genotypes to phenotypes. Topics covered in this timely book range from (i) genome sequencing and genotyping techniques, (ii) genome features such as centromeres and epigenetic regulation, (iii) tools and resources available for trait genomics, to (iv) applications of allele mining and genomics-assisted breeding. This book is a valuable resource for researchers and students interested in maize genetics and genomics.

Download or read book Statistical Population Genomics written by Julien Y Dutheil and published by . This book was released on 2020-10-08 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access volume presents state-of-the-art inference methods in population genomics, focusing on data analysis based on rigorous statistical techniques. After introducing general concepts related to the biology of genomes and their evolution, the book covers state-of-the-art methods for the analysis of genomes in populations, including demography inference, population structure analysis and detection of selection, using both model-based inference and simulation procedures. Last but not least, it offers an overview of the current knowledge acquired by applying such methods to a large variety of eukaryotic organisms. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, pointers to the relevant literature, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and cutting-edge, Statistical Population Genomics aims to promote and ensure successful applications of population genomic methods to an increasing number of model systems and biological questions. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.

Download or read book Evaluation of Tolerance to High Plant Densities and Plant Efficiency of Maize Breeding Population Developed by Recurrent Selection of Grain Yield written by T.M. Crosbie and published by . This book was released on 1978 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several recurrent relection schemes are being used to improve grain-yield performance of several maize (Zea mays L.) populations at the Iowa Agriculture and Home Economics Experiment Station. Three cycles of reciprocal full-sib selection in Iowa Two-ear Synthetic [BS10(FR)] and Pioneer Twc-ear Composite [BS11(FR)], seven cycels of reciprocal recurrent selection in Iowa Stiff Stalk Synthetic [BSSS(R)], Iowa Corn Borer Synthetic #1 [BSCB1(R)], and five cycels of half-sib recurrent selection in Lancaster Surecrop 9LANC) with maize inbred, Hy, as tester have been completed. I grew testcrosses of unimproved and improved populations of BS10(FR), BS11(FR), BSSS(R), BSCB1(R) And LANC, plus population crosses (i.e., CO X CO, CN X CN) of BS10(FR) X BS11(FR) and BSSS(R) X BSCB1(R) at three plant densities in three environments. Testers were maize inbreds Mo17, B77, and B79, My research was conducted: (1) to evaluate respones to plant densities of the CO and CN populations, (2) to study changes in several morphological and physiological traits associated with recurrent selection for increased grain yield, and (3) to caompare results obtained for testcrosses and populations crosses to evaluate combining ability for grain yield, density tolerance, and physiological traits. Reciprocal full-sib selection did not improve the response to plant densities of testcrosses and population crosses of BS10(FR) and BS11(FR). Furthermore, selection did not increase grain yield of BS10(FR) X BS11(FR) at 39.5 and 79.0 M plants/ha or of (...).

Download or read book Evaluation of Tolerance to High Plant Densities and Plant Efficiency of Maize Breeding Populations Developed by Recurrent Selection for Grain Yield written by Theodore M. Crosbie and published by . This book was released on 1978 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Managing Global Genetic Resources written by National Research Council and published by National Academies Press. This book was released on 1993-02-01 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: This anchor volume to the series Managing Global Genetic Resources examines the structure that underlies efforts to preserve genetic material, including the worldwide network of genetic collections; the role of biotechnology; and a host of issues that surround management and use. Among the topics explored are in situ versus ex situ conservation, management of very large collections of genetic material, problems of quarantine, the controversy over ownership or copyright of genetic material, and more.

Download or read book Drought Stress in Maize Zea mays L written by Muhammad Aslam and published by Springer. This book was released on 2015-11-20 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on early germination, one of maize germplasm most important strategies for adapting to drought-induced stress. Some genotypes have the ability to adapt by either reducing water losses or by increasing water uptake. Drought tolerance is also an adaptive strategy that enables crop plants to maintain their normal physiological processes and deliver higher economical yield despite drought stress. Several processes are involved in conferring drought tolerance in maize: the accumulation of osmolytes or antioxidants, plant growth regulators, stress proteins and water channel proteins, transcription factors and signal transduction pathways. Drought is one of the most detrimental forms of abiotic stress around the world and seriously limits the productivity of agricultural crops. Maize, one of the leading cereal crops in the world, is sensitive to drought stress. Maize harvests are affected by drought stress at different growth stages in different regions. Numerous events in the life of maize crops can be affected by drought stress: germination potential, seedling growth, seedling stand establishment, overall growth and development, pollen and silk development, anthesis silking interval, pollination, and embryo, endosperm and kernel development. Though every maize genotype has the ability to avoid or withstand drought stress, there is a concrete need to improve the level of adaptability to drought stress to address the global issue of food security. The most common biological strategies for improving drought stress resistance include screening available maize germplasm for drought tolerance, conventional breeding strategies, and marker-assisted and genomic-assisted breeding and development of transgenic maize. As a comprehensive understanding of the effects of drought stress, adaptive strategies and potential breeding tools is the prerequisite for any sound breeding plan, this brief addresses these aspects.

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 Origin and Geography of Cultivated Plants written by N. I. Vavilov and published by Cambridge University Press. This book was released on 1992-10-22 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of all of Vavgilov's works on the origin and geography of cultivated plant species.

Download or read book Safety of Genetically Engineered Foods written by National Research Council and published by National Academies Press. This book was released on 2004-07-08 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Assists policymakers in evaluating the appropriate scientific methods for detecting unintended changes in food and assessing the potential for adverse health effects from genetically modified products. In this book, the committee recommended that greater scrutiny should be given to foods containing new compounds or unusual amounts of naturally occurring substances, regardless of the method used to create them. The book offers a framework to guide federal agencies in selecting the route of safety assessment. It identifies and recommends several pre- and post-market approaches to guide the assessment of unintended compositional changes that could result from genetically modified foods and research avenues to fill the knowledge gaps.

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 Genetic Engineering of Plants written by National Research Council and published by National Academies Press. This book was released on 1984-02-01 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The book...is, in fact, a short text on the many practical problems...associated with translating the explosion in basic biotechnological research into the next Green Revolution," explains Economic Botany. The book is "a concise and accurate narrative, that also manages to be interesting and personal...a splendid little book." Biotechnology states, "Because of the clarity with which it is written, this thin volume makes a major contribution to improving public understanding of genetic engineering's potential for enlarging the world's food supply...and can be profitably read by practically anyone interested in application of molecular biology to improvement of productivity in agriculture."

Download or read book Broadening the Genetic Base of Crop Production written by H. David Cooper and published by . This book was released on 2001 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the previously neglected interface between the conservation of plant genetic resources and their utilization. Only through utilization can the potential value of conserved genetic resources be realized. However, as this book shows, much conserved germplasm has to be subjected to long-term pre-breeding and genetic enhancement before it can be used in plant breeding programs.The authors explore the rationale and approaches for such pre-breeding efforts as the basis for broadening the genetic bases of crop production. Examples from a range of major food crops are presented and issues analyzed by leading authorities from around the world.