An Analysis of Genetic Variation in Complex Traits of Maize

An Analysis of Genetic Variation in Complex Traits of Maize PDF Author: Jason Andrew Peiffer
Publisher:
ISBN:
Category :
Languages : en
Pages : 144

Get Book Here

Book Description
Maize (Zea mays L.) is a complex crop. Governed by the universal processes of evolution that dictate the differential reproduction of all life, maize germplasm has been gradually adapted to better suit societal needs through domestication and breeding. However, these modifications were largely accomplished with little knowledge of the genetic architecture or molecular mechanics of its traits. Investigating the reaches of the rhizosphere to the top of the tassel, the following studies analyze the natural variation of complex maize traits to better understand both their means and degree of inheritance. First, the heritability and environmental specificity of maize-microbe interactions were estimated by pyrosequence profiling 16s rRNA gene amplicons from rhizosphere bacterial populations of diverse inbreds grown in multiple maize field environments. We found substantial variation in bacterial diversity was attributable to environment. Nonetheless, a small but significant proportion of variation was heritable. While kinship inferred from a simple additive model assuming contributions from all polymorphisms did not explain this heritable variation, its discovery is a step toward identifying those genes responsible for novel plantmicrobe interactions in natural environments. Second, maize stalk strength variation was analyzed to delineate the accuracy of genomic prediction in a low heritability trait. While few robust loci were associated with stalk strength, a significant proportion of heritable variation was captured by kinship among the inbreds. This revealed the efficacy of genomic prediction and suggested the potential to accurately predict other low heritability phenotypes such as yield. These and similar efforts to facilitate the selection of genotyped seed with desirable qualities before planting will enhance breeding efficiency. Finally, variation in the most classic and heritable of complex traits, maize height was partitioned to reveal its genetic architecture and pleiotropy with other traits such as flowering time and node counts. As anticipated height was highly polygenic and well captured by kinship; however, an interesting finding was the lacking concordance between mapped loci and those established through previous cloning efforts. Equally intriguing was the paucity of pleiotropic loci identified for height and flowering time. These findings reveal the potential for independent evolvability of these traits during maize breeding.

An Analysis of Genetic Variation in Complex Traits of Maize

An Analysis of Genetic Variation in Complex Traits of Maize PDF Author: Jason Andrew Peiffer
Publisher:
ISBN:
Category :
Languages : en
Pages : 144

Get Book Here

Book Description
Maize (Zea mays L.) is a complex crop. Governed by the universal processes of evolution that dictate the differential reproduction of all life, maize germplasm has been gradually adapted to better suit societal needs through domestication and breeding. However, these modifications were largely accomplished with little knowledge of the genetic architecture or molecular mechanics of its traits. Investigating the reaches of the rhizosphere to the top of the tassel, the following studies analyze the natural variation of complex maize traits to better understand both their means and degree of inheritance. First, the heritability and environmental specificity of maize-microbe interactions were estimated by pyrosequence profiling 16s rRNA gene amplicons from rhizosphere bacterial populations of diverse inbreds grown in multiple maize field environments. We found substantial variation in bacterial diversity was attributable to environment. Nonetheless, a small but significant proportion of variation was heritable. While kinship inferred from a simple additive model assuming contributions from all polymorphisms did not explain this heritable variation, its discovery is a step toward identifying those genes responsible for novel plantmicrobe interactions in natural environments. Second, maize stalk strength variation was analyzed to delineate the accuracy of genomic prediction in a low heritability trait. While few robust loci were associated with stalk strength, a significant proportion of heritable variation was captured by kinship among the inbreds. This revealed the efficacy of genomic prediction and suggested the potential to accurately predict other low heritability phenotypes such as yield. These and similar efforts to facilitate the selection of genotyped seed with desirable qualities before planting will enhance breeding efficiency. Finally, variation in the most classic and heritable of complex traits, maize height was partitioned to reveal its genetic architecture and pleiotropy with other traits such as flowering time and node counts. As anticipated height was highly polygenic and well captured by kinship; however, an interesting finding was the lacking concordance between mapped loci and those established through previous cloning efforts. Equally intriguing was the paucity of pleiotropic loci identified for height and flowering time. These findings reveal the potential for independent evolvability of these traits during maize breeding.

Genetics, Genomics and Breeding of Maize

Genetics, Genomics and Breeding of Maize PDF Author: Ramakrishna Wusirika
Publisher: CRC Press
ISBN: 1482228130
Category : Science
Languages : en
Pages : 310

Get Book Here

Book Description
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

Specialty Corns

Specialty Corns PDF Author: Arnel R. Hallauer
Publisher: CRC Press
ISBN: 1420038567
Category : Science
Languages : en
Pages : 492

Get Book Here

Book Description
Completely revised and updated, the Second Edition of Specialty Corns includes everything in the first edition and more. Considered the standard in this field, significant changes have been made to keep all the information current and bring the references up-to-date. Two new chapters have been added to keep up with the latest trends: Blue Corn and

The Maize Genome

The Maize Genome PDF Author: Jeffrey Bennetzen
Publisher: Springer
ISBN: 3319974270
Category : Science
Languages : en
Pages : 390

Get Book Here

Book Description
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.

In the Light of Evolution

In the Light of Evolution PDF Author: National Academy of Sciences
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 388

Get Book Here

Book Description
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.

Quantitative Genetics in Maize Breeding

Quantitative Genetics in Maize Breeding PDF Author: Arnel R. Hallauer
Publisher: Springer Science & Business Media
ISBN: 1441907661
Category : Science
Languages : en
Pages : 669

Get Book Here

Book Description
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

The Molecular Basis of Plant Genetic Diversity

The Molecular Basis of Plant Genetic Diversity PDF Author: Mahmut Caliskan
Publisher: IntechOpen
ISBN: 9789535101574
Category : Science
Languages : en
Pages : 372

Get Book Here

Book Description
The Molecular Basis of Plant Genetic Diversity presents chapters revealing the magnitude of genetic variations existing in plant populations. Natural populations contain a considerable genetic variability which provides a genomic flexibility that can be used as a raw material for adaptation to changing environmental conditions. The analysis of genetic diversity provides information about allelic variation at a given locus. The increasing availability of PCR-based molecular markers allows the detailed analyses and evaluation of genetic diversity in plants and also, the detection of genes influencing economically important traits. The purpose of the book is to provide a glimpse into the dynamic process of genetic variation by presenting the thoughts of scientists who are engaged in the generation of new ideas and techniques employed for the assessment of genetic diversity, often from very different perspectives. The book should prove useful to students, researchers, and experts in the area of conservation biology, genetic diversity, and molecular biology.

Molecular Dissection of Complex Traits

Molecular Dissection of Complex Traits PDF Author: Andrew H. Paterson
Publisher: CRC Press
ISBN: 9781420049381
Category : Science
Languages : en
Pages : 328

Get Book Here

Book Description
In the past 10 years, contemporary geneticists using new molecular tools have been able to resolve complex traits into individual genetic components and describe each such component in detail. Molecular Dissection of Complex Traits summarizes the state of the art in molecular analysis of complex traits (QTL mapping), placing new developments in thi

Experimental Studies on the Nature of Species

Experimental Studies on the Nature of Species PDF Author: Jens Clausen
Publisher:
ISBN:
Category : Biogeography
Languages : en
Pages : 452

Get Book Here

Book Description


Genetics and Exploitation of Heterosis in Crops

Genetics and Exploitation of Heterosis in Crops PDF Author: J. G. Coors
Publisher:
ISBN: 9780891185499
Category : Electronic books
Languages : en
Pages : 0

Get Book Here

Book Description
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.