Plant Breeding and Genetics Commons^™

Impact Of One Nucleotide On Organ Enumeration And Phyllotaxy In Arabidopsis Thaliana, Hazel R. Frans, Tara Phelps-Durr

SACAD: Scholarly Activities

Arabidopsis thaliana is a model organism used by scientists to study plant genetics, development, and physiology. CRISPR-Cas9 is a biotechnology tool adapted from a bacterial defense mechanism to precisely edit DNA using a guide mRNA and a Cas9 protein. This project aims to create CRISPR-CAS9 mutations in the APETALA3 (AP3) gene of the model plant Arabidopsis thaliana. AP3 is a class B gene critical to the petal and stamen development of Arabidopsis flowers. The AP3 protein contains a MADS domain, which binds directly to DNA and may be responsible for the expression of the CaRG-box genes. AP3 works in conjunction …

Crispr-Induced Mutagenesis Of Arabidopsis Thaliana Gene Apetala3, Hazel Frans, Tara Phelps-Durr

SACAD: Scholarly Activities

This project aims to create CRISPR-CAS9 mutations in the APETELA3 (AP3) gene of the model plant Arabidopsis thaliana. AP3 is a class B gene critical to the petal and stamen development of Arabidopsis flowers. AP3 is defined in a MADS domain, which binds directly to DNA and may be responsible for the expression of the CaRG-box genes. AP3 works in conjunction with PISTILLATA (PI), AGAMOUS (AG), APETALA1 (AP1), and SEPALLATA (SEP) genes to specify the development in the second and third whorls of the flower. While several alleles of AP3 already exist, these alleles are strong alleles that knockout gene …

Hordeum I Genome Unlocks Adaptive Evolution And Genetic Potential For Crop Improvement, Hao Feng, Qingwei Du, Ying Jiang, Yong Jia, Tianhua He, Yibin Wang, Brett Chapman, Jiaxin Yu, Hiawen Zhang, Mengxue Gu, Mengwei Jiang, Shanshan Gao, Xinjie Zhang, Yameng Song, Vanika Garg, Rajeev K. Varshney, Jianhua Wei, Chengdao Li, Xingtan Zhang, Ruifen Li

Grain and Other Field Crops Research Articles

Crop wild relatives (CWRs) are invaluable for crop improvement. Among these, Hordeum I-genome species exhibit exceptional tolerance to alkali and salt stresses. Here we present a chromosome-scale genome assembly of Hordeum brevisubulatum (II, 2n = 2x =14) and genome resequencing of 38 diploid germplasms spanning 7 I-genome species. We reveal that the adaptive evolution of the H. brevisubulatum genome is shaped by structural variations, some of which may contribute to its adaptation to high alkali and salt environments. Evolutionary duplication of the stress sensor-responder module CaBP-NRT2 and the horizontally transferred fungal gene Fhb7 were identified as novel alkaline–saline …

Evaluating Past Progress And Assessing Prediction Breeding Strategies For Sustained Genetic Gains In The Louisiana Sugarcane Variety Development Program, Brayden A. Blanchard

LSU Doctoral Dissertations

The aim of this dissertation is to outline important considerations for the Louisiana Sugarcane Variety Development Program (LSVDP) as it pertains to historical progress, impact, goal setting, and new strategies for continued genetic gains. Industry progress was evaluated with robust regression models to quantify rates of productivity gains. Over the last 50 years, statistically significant productivity gains were identified in sucrose content (45%), cane yield (32.2%), and sugar yield (93%) while pairwise comparisons of decades showed that progress was incremental rather than rapid and sustained once achieved. The decade from 1990-1999 was identified as the only decade with a significant …

Soybean Genetics, Genomics, And Breeding For Improving Nutritional Value And Reducing Antinutritional Traits In Food And Feed, William M. Singer, Yi-Chen Lee, Zachary Shea, Caio Canella Vieira, Dongho Lee, Xiaoying Li, Mia Cunicelli, Shaila S. Kadam, Mohammad Amir Waseem Khan, Grover Shannon, M. A. Rouf Mian, Henry T. Nguyen, Bo Zhang

Agriculture Faculty Publications

Soybean [Glycine max(L.) Merr.] is a globally important crop due to its valuable seed composition, versatile feed, food, and industrial end-uses, and consistent genetic gain. Successful genetic gain in soybean has led to widespread adaptation and increased value for producers, processors, and consumers. Specific focus on the nutritional quality of soybean seed composition for food and feed has further elucidated genetic knowledge and bolstered breeding progress. Seed components are historical and current targets for soybean breeders seeking to improve nutritional quality of soybean. This article reviews genetic and genomic foundations for improvement of nutritionally important traits, such as protein and …

Integrated Techniques To Identify And Characterize Resistance To Fusarium Wilt Caused By Fusarium Oxysporum, F. Sp. Vasinfectum Race 4 In Two Domesticated Gossypium Species, Stephen Parris

All Dissertations

Fusarium wilt of cotton (Gossypium hirsutum and G. barbadense), caused by Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4), is the most threatening disease faced by today’s cotton breeders. During the past 20 years, over $7 million have been dedicated to efforts in breeding upland cotton for resistance to FOV4 while yielding little to no results. To counteract this, we conducted a study in Clint, TX, that utilized control plots and geostatistical methods to adjust phenotypic data for the heterogeneous distribution of FOV4 in the field, improving the accuracy of genetic resistance assessments. Concurrently, early-generation genetic mapping in …

Breeding Soybean [Glycine Max (L) Merr.] Under Reduced Irrigation, Francia Seconde Ravelombola

Graduate Theses and Dissertations

Soybean [Glycine max (L) Merr.], a legume species native to East Asia in the Fabaceae family, ranks among the most important food crops in the world. It is widely grown and known for its high protein and oil concentration. Soybean is valuable because its seeds have multiple applications in food, feed, pharmaceutical, and industrial enterprises. Even though seed yield is the most important trait, breeders have recently given a significant attention to quality traits, such as high protein or modified oil concentration. Soybean seed protein inheritance has been extensively studied; however, genetics of high-protein ‘BARC-7’ soybean are still unknown.On the …

Genetic Diversity In Helianthus Annuus: Selective Breeding And Induced Mutagenesis, Dillon Holton

Thinking Matters Symposium

H. annuus, more commonly known as the sunflower, is a single species that has many different variations. Traits have been selectively bred for hundreds of years in order to produce a beautiful flower as well as essential agricultural products. Recently interest in the sunflower as a food and fuel crop has led to selective breeding of seeds that produce high yields of sunflower oil. To further push the limits of this plant's genome, researchers have used mutagenesis to force mutations in hopes of developing novel modifications that could increase yield. With the entire genome mapped, the goal for many research …

B.R. Wells Arkansas Rice Research Studies 2020, J. Hardke, X. Sha, N. Bateman

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading rice producer in the United States. The state represents 47.5% of total U.S. rice production and 48.1% of the total acres planted to rice in 2020. Rice cultural practices vary across the state and across the U.S. However, these practices are also dynamic and continue to evolve in response to changing political, environmental, and economic times. This survey was initiated in 2002 to monitor and record changes in the way Arkansas rice producers approach their livelihood. The survey was conducted by polling county extension agents in each of the counties in Arkansas that produce rice. Questions …

Genetic Resistance To The Downy Mildew Pathogen And Breeding Towards Durable Disease Management In Spinach, Bazgha Zia

Graduate Theses and Dissertations

Spinach (Spinacia oleracea) is a self-pollinated, dioecious winter crop. Prevalent challenges to the production of spinach include disease pressure imposed by downy mildew, which is caused by Peronospora effusa (=P. farinosa f. sp. spinaciae [Pfs]). A total of 19 new races of P. effusa have emerged, imposing serious challenges to the disease management in spinach production. Accordingly, this study was designed to explore the genetic components for establishing the basis of durable disease resistance development against the downy mildew pathogen (P. effusa 13) in spinach, through the use of various genome engineering approaches.

Our results have led (Chapter 2) to …

Molecular Genetic Analysis Of Drought Resistance And Productivity Traits Of Rice Genotypes, Yheni Dwiningsih

Graduate Theses and Dissertations

Rice (Oryza sativa L.) is the staple food for a majority of the world’s population, and uses 30% of the global fresh water during its life cycle. Drought at the reproductive stage is the most important abiotic stress factor limiting grain yield. The United States is the third largest exporter of rice, and Arkansas is the top rice-producing state. The Arkansas rice-growing region in the Lower Mississippi belt is among the 10 areas with the highest risk of water scarcity. Adapted U.S. rice cultivars were screened for drought resistant (DR) traits to find sources for breeding U.S. rice cultivars for …

Association Mapping For Soybean (Glycine Max L. Merr.) Protein And Oil Content, Joseph Najjar

Graduate Theses and Dissertations

Soybean [Glycine Max (L.) Merrill] is an important economic crop because of its high content of seed protein and oil. Seed oil and protein content are quantitative inherited traits. The genetics of seed protein and oil levels have been extensively studied, with 367 QTL reported for protein and 475 QTL reported for oil to date. Validation of such QTLs, and identification of easily-automatable molecular markers around these QTL will aid the progression of breeding for such traits. The focus of this research was to discover novel and verify previously reported QTL related to protein and/or oil content via Genome-Wide Association …

Mapping Quantitative Trait Loci For Peach (Prunus Persica) Resistance To Xanthomonas Arboricola Pv. Pruni (Xap) And Determining The Diversity And Virulence Of A United States Xap Collection, Maxwell Vonkreuzhof

Graduate Theses and Dissertations

Bacterial spot, caused by the bacterium Xanthomonas arboricola pv. pruni (Xap), is a threat to the peach [Prunus persica (L.) Batsch], Japanese and European plum (P. salicina L. and P. domestica L.), and tart and sweet cherry (P. cerasus L. and P. avium L.) industries. Markers for fruit resistance to bacterial spot have been developed however, markers associated with foliar resistance have yet to be developed. A total of 130 progeny and 13 parents (n=143) were evaluated for foliar and fruit Xap resistance in 2013, 2014, and 2015, and 162 progeny and eight parents (n=170) in 2017 and 2018 as …

Linkage Mapping For Soybean (Glycine Max) Flood Tolerance, Wade Stiles Hummer

Graduate Theses and Dissertations

Flood tolerance in soybean (Glycine max) is not a well-characterized trait, yet flooding damage is second only to drought stress in terms of yield reduction. The objectives of this study were to determine genetic variation for flooding tolerance in two populations of soybean recombinant inbred lines (RILs) and to identify and confirm flood tolerant QTL. Population A (WHA) consisted of 111 RILs derived from the cross 5002T by 91210-350 and Population B (WHB) consisted of 79 RILs from the cross RA-452 by Osage. Experiments were conducted at the Rice Research and Extension Center (RREC) near Stuttgart, AR in 2015 and …

Genome Wide Association Studies For Identification Of Markers Linked To Sucrose Traits In Sugarcane, Nathanael Darrell Fickett

LSU Doctoral Dissertations

Sugarcane, being a complex aneu-polyploid, poses unique challenges to fine mapping of quantitative trait loci (QTL) controlling agronomic traits of interest. Genome-wide association studies (GWAS) could be a better alternative to identify molecular markers associated with specific traits due to high linkage disequilibrium in sugarcane. In the first study, marker-trait associations (MTAs) were evaluated for three sucrose traits, Brix, total recoverable sugar (TRS), and percent sucrose on 48 elite and historic Louisiana breeding clones using 1,062 alleles. These sucrose traits were highly correlated (P-value < 0.0001) at >0.96. TASSEL 5.1 and JMP Genomics 8.0 were compared with eight models run in each program. …

Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind

Theses and Dissertations

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence …

Applying Molecular And Phenotypic Tools To Characterize Flesh Texture And Acidity Traits In The Arkansas Peach Breeding Program And Understanding The Crispy Texture In The Arkansas Blackberry Breeding Program, Alejandra Andrea Salgado Rojas

Graduate Theses and Dissertations

Quantitative trait loci (QTL) utilizing a pedigree-based analysis (PBA) approach was performed in the peach breeding program for the first time. The pedigree consisted of seven-F1 populations, their parents, ancestors, and cultivars. Flesh firmness and titratable acidity (TA) were examined in 2011, 2012, and 2013. For TA, a consistent and strong QTL was identified on the proximal end of linkage group (LG) 5 of the peach genome. For flesh firmness, two QTLs were located on LG 4. The first QTL was located on the chromosomal region where the slow-melting flesh (SMF) DNA test was identified, and the second QTL was …

Genetically Modified Canola Trials In 2009, Department Of Agriculture And Food, Western Australia

Research Reports

During 2009, just over 860 hectares of Roundup Ready® canola were grown in Western Australia enabled by an exemption order under the Genetically Modified Crops Free Areas Act 2003. The aim of the trials was to establish whether GM canola could be segregated from non-GM canola along the WA supply chain, and whether GM canola was agronomically viable for WA farming systems. This was the first time genetically modified canola had been grown on a commercial scale in WA - earlier exemptions for smaller trials had been for variety testing and scientific purposes.

Crop Updates 2000 - Weeds, Vanessa Stewart, David Minkey, Abul Hashem, Glen Riethmuller, Martin Harries, Peter Newman, Cameron Weeks, Harmohinder S. Dhammu, Aik Cheam, David Bowran, Terry Piper, Alexandra Wallace, Bill Roy, Keith L. Devenish, Lisa J. Leaver, Brad Rayner, Mike Collins, Marta Monardino, David Pannell, Stephen Powles, Sally Peltzer, Michael Walsh, Charles Boyle, P. Neve, D. Lorraine-Colwill, C. Preston, Art Diggle, Rick Llewellyn, Ryan Duane, Siew Lee, David Nicholson, Peter Carlton, Stewart Smith, Bill Crabtree, Gordon Cumming, David Cameron, Mike Jackson, Scott Paton, John R. Peirce, Greg Shea

Crop Updates

This session covers thirty six papers from different authors:

INTRODUCTION, Vanessa Stewart Agriculture Western Australia

INTEGRATED WEED MANAGEMENT

1. Effect of seeding density, row spacing and Trifluralin on the competitive ability of Annual Ryegrass in a minimum tillage system, David Minkey, Abul Hashem, Glen Riethmuller and Martin Harries, Agriculture Western Australia

2. High wheat seeding rates coupled with narrow row spacing increases yield and suppresses grass, Peter Newman¹ and Cameron Weeks²,¹Agronomist, Elders Limited ²Mingenew/Irwin Group

3. Resistant ryegrass management in a wheat – lupin rotation, Abul Hashem, Harmohinder S. Dhammu, Aik Cheam, David Bowran and …

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Postpollination Mechanisms Influencing Mating Patterns And Fecundity: An Example From Eichhornia Paniculata, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Plant mating systems are influenced by the amount and genetic composition of pollen grains deposited on stigmas and by the ability of recipients to discriminate among pollen from different sources. We describe an experimental procedure that uses limiting and excess pollinations with mixtures of genetically marked pollen to partition the siring success of donors into three components: prefertilization gamete attrition (failure of male gametophytes before fertilization), pollen competitive ability (differences in pollen tube growth rate), and postfertilization gamete attrition (embryo abortion). Regression models for the relationships of pollen load size with each pollen's siring success and total recipient fecundity indicate …

Genetic Studies Of Winter Hardiness In Barley, C. R. Rohde, C. F. Pulham

Nebraska Agricultural Experiment Station: Historical Research Bulletins

An important obstacle toward the development of winter barley varieties with a higher level of winter hardiness has been the deficiency of genetic information on this character. The primary objective of these studies was to obtain information on the genetics of the winter hardiness of a group of 18 winter barley varieties which originated from widely different geographic areas of the world. It was hoped that this information might be helpful in determining whether or not it would be possible for barley breeders to combine different genetic sources of winter hardiness and attain a higher level of hardiness than presently …

The Immediate Effect Of Gametic Relationship And Of Parental Type Upon The Kernel Weight Of Corn, T. A. Kiesselbach

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This investigation to determine the relation of the kernel weight of corn to the source of pollen with which it was fertilized has been made to answer several questions of both practical and technical interest: (1) To what extent is kernel weight affected in the current crop by the "breadth of breeding" or the gametic relationship? (2) What is the relation of the diversity of parental type to the immediate effect of foreign pollen upon the kernel weight of corn? (3) Is the immediate effect of cross-fertilization upon the kernel weight of sufficient importance to justify the annual mixing of …