Download or read book Dissection of the Genetic Architecture of Domestication Traits in Maize and Its Ancestor Teosinte written by Chin Jian Yang and published by . This book was released on 2018 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Domestication provides an excellent model for understanding the evolution of quantitative traits due to strong morphological divergence that is often accompanied by profound genetics divergence between the domesticate and its ancestor. Here, we are interested in using maize domestication as a model for understanding genetic changes that distinguish maize from its ancestor teosinte. Beginning at a single gene level, we identified a gene called ZmYAB2.1 through quantitative trait locus (QTL) fine-mapping. ZmYAB2.1 was selected for lower expression in maize which led to shorter ear internode length and more compact grains on an ear for improving harvestability. Further characterization of ZmYAB2.1 revealed that this gene acts in a background dependent manner. Subsequently, we expanded our approach to multiple genes level by mapping QTLs for sexual conversion of the terminal lateral inflorescence in maize. We identified three QTLs (STAM1.1, STAM1.2 and STAM2.1) that are responsible for the sexual conversion and other related domestication traits. Additionally, we also narrowed STAM2.1 down to a 600 kb region with two candidate genes. As our perspective moved from a single gene to a network of multiple genes, we were keen on understanding the genetic changes during domestication on a broader scale. We sampled 18 traits in two large populations of teosinte and maize landrace for estimating additive and dominance genetic variances, genetic-by-environment variances, genetic correlations and genetic covariances. While we observed variable divergence among the 18 domestication traits, we identified a consistent pattern of reduced genetics variability in reproduction-related traits. We inferred weak selection intensities across all domestication traits and moderate genetic constraint during early domestication. We showed that selection for more grains along a single row on an ear would lead to the largest evolutionary gain in all domestication traits with minimal constraint. Overall, our approaches in studying maize domestication offer several different perspectives on the evolution of a major crop from a wild plant.
Download or read book The Genetic Architecture of Maize Domestication and Range Expansion written by and published by . This book was released on 2013 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: The genetic architecture of the evolution of extreme morphological divergence is one of the fundamental questions of evolutionary biology. Maize (Zea Mays ssp. mays) and its wild ancestor, teosinte (Zea mays ssp. parviglumis) provide an ideal model for examining this question in part because of their extreme phenotypic divergence in plant architecture, ear morphology, and environmental range. In order to examine the genetic changes underlying this divergence, we use a population of maize-teosinte BC2S3 RILs. Using these RILs allows us to examine genetic architecture on multiple levels. First, whole genome QTL mapping is used to explore the diversity of genetic architectures which control domestication traits. These genetic architectures range from nearly Mendelian to polygenic. For two near Mendelian traits, glume architecture and barren ear base, the largest QTL contained a single gene in the 1.5 LOD confidence interval. The most polygenic trait was ear diameter, for which we found 35 QTL of varying effect sizes. As part of this project we extended the capabilities of the statistical program R/qtl to apply to a wider variety of experimental crosses. In order to examine the causes of extreme morphological divergence on the single gene level, we fine-mapped a single gene, ZmCCT which controls an approximately 9 day difference in flowering time between the homozygous maize and teosinte classes. We demonstrate that the causative difference is cis-regulatory, as under long day lengths ZmCCT alleles from diverse teosintes were consistently expressed at a higher level than the corresponding temperate maize alleles. Taken together these results provide examples of the variety of ways in which complex traits evolve.
Download or read book The Complex Inheritance of Maize Domestication Traits and Gene Expression written by and published by . This book was released on 2014 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: The genetic basis for morphological change in divergent species is a central question in evolutionary biology. The domestication of maize from its wild progenitor, teosinte, is an excellent system to address this question. We explore the large effect on domestication phenotypes of a poorly understood region of the maize genome using a chromosome five specific mapping population. Unlike other large effect regions of the maize genome, many traits have multiple QTL that do not stack on a single locus suggesting multiple genes on the fifth chromosome influence domestication traits. Simulation studies show clear evidence for limited power to detect QTL for highly polygenic traits that do not accurately portray the true complexity of the underlying genetic architecture. Two QTL in different locations were chosen for fine mapping studies to identify the underlying causative genes. While a single gene was not identified for either QTL, both were successfully narrowed to less than three centimorgan intervals with relatively few genes and evidence of positive selection during maize domestication. Finally, the first genome-wide effort to characterize cis and trans regulatory change between a domesticated crop and its wild progenitor found extensive regulatory variation with relatively few genes having consistent cis differences, which were determined to be under positive selection during the domestication and crop improvement of maize. Consistent with loss of diversity during the domestication bottleneck, cis expression variation explained by the maize parent is reduced in comparison to teosinte with an even greater reduction seen in cis candidate genes. A general increase in the expression of maize alleles was also observed suggesting domestication in maize may have led to a general increase in gene expression. Collectively, these experiments shed light on the evolution of divergent phenotypes and gene regulation in the domesticated maize and its wild progenitor.
Download or read book Fine mapping Major Domestication QTL on Chromosome Five in Zea Mays written by Alessandra Margaruite York and published by . This book was released on 2018 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize was domesticated from its wild ancestor, teosinte, approximately 9000 years ago and serves as an excellent model to study rapid evolution. This is because maize and teosinte provide an example of extreme morphological divergence in both its plant architecture and structure of its ears. Even with their drastic phenotypic differences, they are able to develop fully fertile offspring that allows us to study the genes responsible for the domestication process. To understand this process better, quantitative trait loci (QTL) mapping has been conducted to identify causal regions of the genome for many domestication traits. One major region of large effect is located on chromosome five. Specifically, many QTL associated with ear morphology are localized to this region. This work has aims to study this and has manifested into two different projects, both examining major domestication QTL identified on chromosome five. One investigates multiple ear size phenotypes co-localizing to the same region, while the other studies a known homolog for domestication of the nonshattering trait in other cereals. Both QTL had been previously identified in different maize-teosinte hybrid mapping populations and were excellent candidates for further study. Each project sheds light on a poorly understood region of the maize genome and the limitations of studying phenotypic traits with a complex genetic architecture. Together, this work demonstrates the complexity of the evolutionary process. In addition to this work, the final chapter highlights my interest in teaching and learning and delves into research that promotes diversity in STEM education by examining the effect of peer mentoring in a first-year STEM classroom.
Download or read book Genetic Architecture of Domestication and Other Complex Traits in Maize written by Shang Xue and published by . This book was released on 2017 with total page 200 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 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 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 Handbook of Maize Its Biology written by Jeff L. Bennetzen and published by Springer Science & Business Media. This book was released on 2008-12-25 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Maize: Its Biology centers on the past, present and future of maize as a model for plant science research and crop improvement. The book includes brief, focused chapters from the foremost maize experts and features a succinct collection of informative images representing the maize germplasm collection.
Download or read book Specialty Corns written by Arnel R. Hallauer and published by CRC Press. This book was released on 2000-08-23 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Manual on MUTATION BREEDING THIRD EDITION written by Food and Agriculture Organization of the United Nations and published by Food & Agriculture Org.. This book was released on 2018-10-09 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper provides guidelines for new high-throughput screening methods – both phenotypic and genotypic – to enable the detection of rare mutant traits, and reviews techniques for increasing the efficiency of crop mutation breeding.
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.
Download or read book Maize genetic resources written by and published by CIMMYT. This book was released on 1995 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plant Systems Biology written by Sacha Baginsky and published by Springer Science & Business Media. This book was released on 2007-06-25 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume aims to provide a timely view of the state-of-the-art in systems biology. The editors take the opportunity to define systems biology as they and the contributing authors see it, and this will lay the groundwork for future studies. The volume is well-suited to both students and researchers interested in the methods of systems biology. Although the focus is on plant systems biology, the proposed material could be suitably applied to any organism.
Download or read book Association Mapping in Plants written by Nnadozie C. Oraguzie and published by Springer Science & Business Media. This book was released on 2007-01-06 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides both basic and advanced understanding of association mapping and an awareness of population genomics tools to facilitate mapping and identification of the underlying causes of quantitative trait variation in plants. It acts as a useful review of the marker technology, the statistical methodology, and the progress to date. It also offers guides to the use of single nucleotide polymorphisms (SNPs) in association studies.
Download or read book Genetics and Genomics of the Brassicaceae written by Renate Schmidt and published by Springer Science & Business Media. This book was released on 2010-12-03 with total page 675 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Genetics and Genomics of the Brassicaceae provides a review of this important family (commonly termed the mustard family, or Cruciferae). The family contains several cultivated species, including radish, rocket, watercress, wasabi and horseradish, in addition to the vegetable and oil crops of the Brassica genus. There are numerous further species with great potential for exploitation in 21st century agriculture, particularly as sources of bioactive chemicals. These opportunities are reviewed, in the context of the Brassicaceae in agriculture. More detailed descriptions are provided of the genetics of the cultivated Brassica crops, including both the species producing most of the brassica vegetable crops (B. rapa and B. oleracea) and the principal species producing oilseed crops (B. napus and B. juncea). The Brassicaceae also include important “model” plant species. Most prominent is Arabidopsis thaliana, the first plant species to have its genome sequenced. Natural genetic variation is reviewed for A. thaliana, as are the genetics of the closely related A. lyrata and of the genus Capsella. Self incompatibility is widespread in the Brassicaceae, and this subject is reviewed. Interest arising from both the commercial value of crop species of the Brassicaceae and the importance of Arabidopsis thaliana as a model species, has led to the development of numerous resources to support research. These are reviewed, including germplasm and genomic library resources, and resources for reverse genetics, metabolomics, bioinformatics and transformation. Molecular studies of the genomes of species of the Brassicaceae revealed extensive genome duplication, indicative of multiple polyploidy events during evolution. In some species, such as Brassica napus, there is evidence of multiple rounds of polyploidy during its relatively recent evolution, thus the Brassicaceae represent an excellent model system for the study of the impacts of polyploidy and the subsequent process of diploidisation, whereby the genome stabilises. Sequence-level characterization of the genomes of Arabidopsis thaliana and Brassica rapa are presented, along with summaries of comparative studies conducted at both linkage map and sequence level, and analysis of the structural and functional evolution of resynthesised polyploids, along with a description of the phylogeny and karyotype evolution of the Brassicaceae. Finally, some perspectives of the editors are presented. These focus upon the Brassicaceae species as models for studying genome evolution following polyploidy, the impact of advances in genome sequencing technology, prospects for future transcriptome analysis and upcoming model systems.
Download or read book Plant Breeding in the Omics Era written by Rodomiro Ortiz Ríos and published by Springer. This book was released on 2015-09-16 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of plant breeding has grown rapidly in the last decade with breakthrough research in genetics and genomics, inbred development, population improvement, hybrids, clones, self-pollinated crops, polyploidy, transgenic breeding and more. This book discusses the latest developments in all these areas but explores the next generation of needs and discoveries including omics beyond genomics, cultivar seeds and intellectual and property rights. This book is a leading-edge publication of the latest results and forecasts important areas of future needs and applications.
