Download or read book Evaluation and Application of Methods for the Identification of Favourable Alleles for Improvement of Hybrids in Maize Zea Mays L written by N. S. Barua and published by . This book was released on 1998 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Genetic Studies and Identification of Favourable Alleles for the Improvment of Single Cross Hybrids of Maize Zea Mays L written by D. M. Reddy and published by . This book was released on 1998 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Identification of Elite Inbred Lines Harbouring Favourable Alleles and Prediction and Validation of Type of Breeding Population to Improve UAS Bangalore Bred Maize Zea Mays L Hybrids written by Siddu Basavaraj Chindi and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Resource Allocation and Genomic Prediction in Maize Zea Mays L Hybrid Breeding and a Genetic Analysis of Pericarp Pigmentation written by Dylan Schoemaker and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize (Zea mays L.) is a globally important crop species sold as a hybrid and is a model system for both genetics and plant breeding research. The maize breeding process involves identification of new inbred lines, followed by the identification and production of commercial hybrids from crosses of inbreds. Genomic selection and evaluation of hybrid phenotypes are important components of this process. In this dissertation, I use a large multi-environment trial dataset to explore the impact of resource allocation when developing genomic prediction models. Resource-efficient training sets can be developed using three to five environments and a single tester to predict both plant height and grain yield. A second study in my dissertation focused on prediction of hybrid combinations and the importance of general and specific combining ability in identifying new hybrids. The results demonstrated that hybrids with the greatest grain yield result from parents with a high general combining ability, but hybrids with the greatest performance may not have the largest specific combining ability deviation. Therefore, modeling only additive genetic relationships can lead to an accurate genomic prediction model during early-stage testing in a hybrid maize breeding program. The third study in my dissertation was a genetic analysis of pericarp pigmentation in progenies of commercial dent germplasm. Allelic variation at the well-studied pericarp color1 (P1) locus was significantly associated with pericarp pigmentation. The results from these projects provide novel insight into the design of hybrid breeding programs and the allocation of resources when implementing genomic selection. The research also provides candidate genes for geneticists or maize breeders to aid in the development of inbred lines with novel pericarp hues and elite agronomic characteristics.

Download or read book Genetics Genomics and Breeding of Maize written by Ramakrishna Wusirika and published by CRC Press. This book was released on 2014-08-05 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sequencing of the maize genome has opened up new opportunities in maize breeding, genetics and genomics research. This book highlights modern trends in development of hybrids, analysis of genetic diversity, molecular breeding, comparative and functional genomics, epigenomicsand proteomics in maize. The use of maize in biofuels, phytoremediation and

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 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 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 Advances in Agronomy written by and published by Academic Press. This book was released on 1997-02-20 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 59 contains seven reviews covering key contemporary topics on crop and soil sciences. As always, the topics are varied and exemplary of the array of subject matter covered by this long-running serial. Crop science is represented by chapters on quantitative genetics and plant breeding, wheat, perennial forages, and cotton. These chapters are balanced by synthetic reviews of organoclays in pollution abatement, the applications of micromorphology, and the importance of long-term field research. With this latest volume, Advances in Agronomy continues to be recognized as a leading reference and as a first-rate source of the latest research in agronomy, crop science, and soil science. Quantitative genetics Organoclays and pollution Phenology, development, and growth Micromorphology and agronomy Physiological and morphological responses to stress Crop modeling The value of long-term experiments

Download or read book Principles and Procedures of Plant Breeding written by G. S. Chahal and published by CRC Press. This book was released on 2002 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering traditional and emerging breeding procedures, this book explores the scientific bases and details of breeding plants. It puts a special emphasis on the further refinements possible in the light of the latest developments in molecular biology. Specific breeding methods in self and cross-pollinated crops, their genetic basis and scope of further refinements, concepts and techniques of tissue culture, molecular biology and production of transgenic plants, commonly used experimental designs in plant breeding, seed production, and implications of plant breeder's rights are other highlights.

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 Leveraging Genetic Diversity in Maize Breeding written by Alden Perkins and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize (Zea mays L.) cultivars grown in the United States are not closely related to cultivars found in many other parts of the world, and pedigree records suggest that there has been little use of germplasm from other countries in US maize breeding. Exotic germplasm could be a useful source of alleles for improving traits such as grain quality, disease resistance, and abiotic stress tolerance in US populations. Exotic cultivars may also contain alleles that confer adaptation to different climate conditions and management practices, however, which could be detrimental in US growing environments. This dissertation contains a review article about the importance of genetic diversity in breeding and three research projects that involve the incorporation of exotic diversity into US maize germplasm. In the first research project, we investigated the effects of introgressions from open-pollinated populations that originated in Latin America on the performance of maize hybrids in US environments. We compared the phenotypic stability of exotic-derived hybrids and US-adapted hybrids, and we found that the two groups had significantly different stability values for grain yield and flowering time. In the second project, we estimated the effects of exotic introgressions contained in maize populations created by a public-private partnership on grain protein content, kernel vitreousness, and other agronomic traits. One introgression was estimated to increase grain protein content by 0.78%, although it was also associated with detrimental changes in the time of flowering and plant height. Finally, we compared models that could be used to predict the phenotypes of untested hybrids in diverse populations, which could make the process of incorporating new diversity into US germplasm more efficient. We found that models using near-infrared absorbance data collected on inbred seeds as predictors were inferior to models based on genotypic data in most cases, although the difference between the methods was small for traits such as grain moisture and test weight. An alternative to the standard genomic best linear unbiased prediction (GBLUP) method that included additional regularization, called the sparse selection index method, was superior to GBLUP models when large training populations were available. Collectively, the results from these projects provide new insights into how exotic germplasm can be used in US maize breeding most effectively.

Download or read book An Evaluation of Allelic Diversity and Heterosis of Expired Plant Variety Protection Germplasm and a Novel Scheme to Evaluate Hybrid Response to Density in Maize zea Mays L written by Michael Robert White and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Breeding for yield and stability of major staple crops in the world, including maize, will be necessary to support the growing global population in the face of environmental instability due to climate change. The privatization and globalization of maize breeding has transformed the largely public effort into relatively few independent major corporate developers. Twenty-years after the development of a new inbred line, Plant Variety Protection (PVP) expires for inbreds and they become publicly available. My dissertation has three main objectives: (1) characterize the diversity present in the current set of ex-PVP inbreds (2) investigate haplotypes and their implications of heterosis (3) introduce a novel experimental design evaluation plot and evaluate its capacity for assessing planting density response. For the first and third chapters of my thesis, ex-PVP inbreds were classified into eight heterotic subgroups. These subgroups represent founder clusters within the primary Stiff Stalk and non-Stiff Stalk heterotic patterns. Haplotypes fixed for diversity towards the founder allele were found within heterotic subgroups. Quantitative Trait Locus (QTL) analysis of a nested factorial mapping resource crossed to two testers identified QTL that coincided with haplotypes fixed for diversity within heterotic subgroups, supporting the hypothesis that these haplotypes play a role in the complementary nature of heterosis. For the second chapter of my thesis, the Ever-increasing Density plot was used to analyze the response of hybrids to planting density using image-based phenotyping or grain yield components. A diallel analysis suggested that additive inheritance contributed substantially to the responses to increasing planting density. QTL analysis was performed on the response of yield components' to planting density in nested factorial mapping population. Parental allele effects at significant QTL agreed with the general combining ability estimates found in the diallel analysis. In summary, these three components of my research have classified publicly available ex-PVP germplasm into heterotic subgroups, and identified QTL important for performance. This information will be useful to small share breeders in utilizing this germplasm. I also introduce an alternative evaluation plot design to assess hybrid response to planting density and demonstrate its utility in genetic analysis and breeding. This research addresses supports global capacity to improve yield and stability in maize for greater food security in the future.

Download or read book Genetics Abstracts written by and published by . This book was released on 1999 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Qtl Analysis and Evaluation of Seed Production Environment for Maize Zea Mays L Seedling Emergence and Characterization of Sugary1 Alleles for Seed Composition Seedling Emergence and ISA1 Activity written by and published by . This book was released on 2012 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize ( Zea mays ssp. mays) was domesticated from a lowland race of teosinte (Zea mays ssp. parviglumis) in a single domestication event approximately 9,000 years ago in central Mexico. Through the process of domestication, maize experienced a genetic bottleneck and selection that caused a loss of allelic variation across the whole genome and at potentially important loci in modern maize. Seedling emergence is one trait associated with a domestication syndrome, however, its underlying genetic structure and importance during domestication of maize is unknown. Analysis of the nucleotide diversity of genes in the starch synthesis pathway has identified a signature of selection at sugary1 (su1) indicating that the locus was putatively important for the domestication of maize. At least five naturally occurring alleles at the su1 locus have been identified. The first research chapter uses two maize by teosinte NIL populations (W22 and B73) to evaluate seedling emergence from multiple seed production environments. Analysis of both populations identified significant seed production and genotype by seed production effects for seedling emergence traits. Use of multiple seed production environments is important for the evaluation of seedling emergence traits and in studies to identify their genetic structure. Further research is necessary to confirm the identified QTL as loci putatively important for seedling emergence during maize domestication. The second research chapter characterized five naturally occurring su1 mutant alleles for seedling emergence, field traits, mature kernel composition, and ISA1 enzyme activity. These five alleles were backcrossed to A619 and A632, two modern maize inbred lines. The su1 mutant lines were grown in three seed production environments to evaluate seedling emergence, field traits, and mature kernel composition. Immature kernels were used for analysis of starch composition and enzymatic activity. Significant differences were identified among the su1 mutant lines for the evaluated germination and emergence traits. Differences were observed in the presence of ISA1 enzyme; however, no functional ISA1 enzyme activity was observed. Further research is necessary to elucidate the differences for appearance, starch composition, and seed germination and emergence traits in lines with no functional ISA1 enzyme activity.

Download or read book Handbook of Maize written by Jeff L. Bennetzen and published by Springer Science & Business Media. This book was released on 2009-01-16 with total page 785 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize is one of the world’s highest value crops, with a multibillion dollar annual contribution to agriculture. The great adaptability and high yields available for maize as a food, feed and forage crop have led to its current production on over 140 million hectares worldwide, with acreage continuing to grow at the expense of other crops. In terms of tons of cereal grain produced worldwide, maize has been number one for many years. Moreover, maize is expanding its contribution to non-food uses, including as a major source of ethanol as a fuel additive or fuel alternative in the US. In addition, maize has been at the center of the transgenic plant controversy, serving as the first food crop with released transgenic varieties. By 2008, maize will have its genome sequence released, providing the sequence of the first average-size plant genome (the four plant genomes that are now sequenced come from unusually tiny genomes) and of the most complex genome sequenced from any organism. Among plant science researchers, maize has the second largest and most productive research community, trailing only the Arabidopsis community in scale and significance. At the applied research and commercial improvement levels, maize has no peers in agriculture, and consists of thousands of contributors worthwhile. A comprehensive book on the biology of maize has not been published. The "Handbook of Maize: the Genetics and Genomics" center on the past, present and future of maize as a model for plant science research and crop improvement. The books include brief, focused chapters from the foremost maize experts and feature a succinct collection of informative images representing the maize germplasm collection.