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Deconstructing The Genetic Architecture Of Iron Deficiency Chlorosis In Soybean Using Genome-Wide Approaches, Teshale Assefa, Jiaoping Zhang, R. V. Chowda-Reddy, Adrienne N. Moran Lauter, Arti Singh, Jamie A. O'Rourke, Michelle A. Graham, Asheesh K. Singh Jan 2020

Deconstructing The Genetic Architecture Of Iron Deficiency Chlorosis In Soybean Using Genome-Wide Approaches, Teshale Assefa, Jiaoping Zhang, R. V. Chowda-Reddy, Adrienne N. Moran Lauter, Arti Singh, Jamie A. O'Rourke, Michelle A. Graham, Asheesh K. Singh

Agronomy Publications

Background: Iron (Fe) is an essential micronutrient for plant growth and development. Iron deficiency chlorosis (IDC), caused by calcareous soils or high soil pH, can limit iron availability, negatively affecting soybean (Glycine max) yield. This study leverages genome-wide association study (GWAS) and a genome-wide epistatic study (GWES) with previous gene expression studies to identify regions of the soybean genome important in iron deficiency tolerance.

Results: A GWAS and a GWES were performed using 460 diverse soybean PI lines from 27 countries, in field and hydroponic iron stress conditions, using more than 36,000 single nucleotide polymorphism (SNP) markers. Combining this ...


Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges, Mark A. Chamberlin, Marc C. Albertsen, Harry T. Horner Oct 2017

Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges, Mark A. Chamberlin, Marc C. Albertsen, Harry T. Horner

Genetics, Development and Cell Biology Publications

Premise of research. A male-sterile, female-sterile mutant was discovered in a w4-m mutable line of Glycine max L. The mechanism of its sterility was not well understood. Therefore, different cytological and microscopic techniques were undertaken to better understand the process of mutant phenotype development. Molecular research indicated that mer3 was responsible for the sterility.

Methodology. Macro images were collected of whole plants, flowers, anthers, pods, and ovules. Chromosome spreads from anthers at various meiotic stages were examined. Confocal scanning laser microscopy using optical sectioning was utilized on whole anthers and ovules at various developmental stages. Whole mature anthers and ...


Genetic Architecture Of Charcoal Rot (Macrophomina Phaseolina) Resistance In Soybean Revealed Using A Diverse Panel, Sara M. Coser, R. V. Chowda Reddy, Jiaoping Zhang, Daren S. Mueller, Alemu Mengistu, Kiersten A. Wise, Tom W. Allen, Arti Singh, Asheesh K. Singh Sep 2017

Genetic Architecture Of Charcoal Rot (Macrophomina Phaseolina) Resistance In Soybean Revealed Using A Diverse Panel, Sara M. Coser, R. V. Chowda Reddy, Jiaoping Zhang, Daren S. Mueller, Alemu Mengistu, Kiersten A. Wise, Tom W. Allen, Arti Singh, Asheesh K. Singh

Agronomy Publications

Charcoal rot (CR) disease caused by Macrophomina phaseolina is responsible for significant yield losses in soybean production. Among the methods available for controlling this disease, breeding for resistance is the most promising. Progress in breeding efforts has been slow due to the insufficient information available on the genetic mechanisms related to resistance. Genome-wide association studies (GWAS) enable unraveling the genetic architecture of resistance and identification of causal genes. The aims of this study were to identify new sources of resistance to CR in a collection of 459 diverse plant introductions from the USDA Soybean Germplasm Core Collection using field and ...


Advancing Our Understanding Of Charcoal Rot In Soybeans, Martha P. Romero Luna, Daren Mueller, Alemu Mengistu, Asheesh K. Singh, Glen L. Hartman, Kiersten A. Wise Jan 2017

Advancing Our Understanding Of Charcoal Rot In Soybeans, Martha P. Romero Luna, Daren Mueller, Alemu Mengistu, Asheesh K. Singh, Glen L. Hartman, Kiersten A. Wise

Agronomy Publications

Charcoal rot [Macrophomina phaseolina (Tassi) Goid] of soybean [Glycine max (L.) Merr.] is an important but commonly misidentified disease, and very few summary articles exist on this pathosystem. Research conducted over the past 10 yr has improved our understanding of the environment conducive to disease development, host resistance, and improved disease diagnosis and management. This article summarizes the currently available research with an emphasis on disease management.


Virus-Induced Gene Silencing And Transient Gene Expression In Soybean (Glycine Max) Using Bean Pod Mottle Virus Infectious Clones, Steven A. Whitham, Lori M. Lincoln, R. V. Chowda-Reddy, Jaime D. Dittman, Jamie A. O'Rourke, Michelle A. Graham Jun 2016

Virus-Induced Gene Silencing And Transient Gene Expression In Soybean (Glycine Max) Using Bean Pod Mottle Virus Infectious Clones, Steven A. Whitham, Lori M. Lincoln, R. V. Chowda-Reddy, Jaime D. Dittman, Jamie A. O'Rourke, Michelle A. Graham

Plant Pathology and Microbiology Publications

Virus-induced gene silencing (VIGS) is a powerful and rapid approach for determining the functions of plant genes. The basis of VIGS is that a viral genome is engineered so that it can carry fragments of plant genes, typically in the 200 to 300 base pair size range. The recombinant viruses are used to infect experimental plants, and wherever the virus invades, the target gene or genes will be silenced. VIGS is thus transient, and in the span of a few weeks, it is possible to design VIGS constructs and then generate loss-of-function phenotypes through RNA silencing of the target genes ...


Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges Jan 2016

Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges

Graduate Theses and Dissertations

A male-sterile, female-sterile mutant was identified in a transposon-tagging study in soybean (Glycine max L.). This mutant displayed abnormalities in both micro- and mega-sporogenesis, as well as gametogenesis. Vegetatively, the mutant showed no visible differences from the wild-type phenotype. Analyses of male meiotic chromosomes were done to better understand any issues that could occur to cause sterility. Wild-type and mutant anthers and ovules were cleared throughout their development, followed by confocal scanning laser microscopy to look for any abnormalities, and to determine the timing of abortion in both the male and female organs in the mutant. Additionally, scanning electron microscopy ...


The Genetics Of Fertility In Soybean, Reid G. Palmer, Devinder Sandhu, Harry T. Horner, Ram J. Singh Jan 2012

The Genetics Of Fertility In Soybean, Reid G. Palmer, Devinder Sandhu, Harry T. Horner, Ram J. Singh

Genetics, Development and Cell Biology Presentations, Posters and Proceedings

Male and female reproductive structures play an important role in seed development in plants. Abnormalities in male or female reproductive structures can lead to sterility. In soybean, Glycine max (L.) Merr., about 75 sterility mutants have been identified and most of them have been mapped to chromosomes. Mapping results have shown that some chromosomal regions are hotspots for fertility genes. Fine mapping of some of the male-sterile, female-fertile mutants and male-sterile, femalesterile mutants resulted in identification of candidate genes for fertility. Sequence comparisons further helped in locating a few putative candidates. A CACTA- like transposable element that is responsible for ...


A Type Ii Metacaspase Interacts With Rps1-K-2 In Soybean And Analysis Of The Soybean Metacaspase Gene Family, James Andrew Baskett Jan 2012

A Type Ii Metacaspase Interacts With Rps1-K-2 In Soybean And Analysis Of The Soybean Metacaspase Gene Family, James Andrew Baskett

Graduate Theses and Dissertations

Soybean suffers from the root and stem rot disease caused by the oomycete pathogen, Phytophthora sojae. A series of Rps genes confer Phytophthora resistance, and have been utilized in fighting this serious disease in soybean. Earlier we reported the cloning of the coiled coil-nucleotide binding-leucine rich repeat gene, Rps1-k-2. Here we report the identification of a type II metacaspase, Gmmc11 that interacted with the coiled-coil (CC) domain of Rps1-k-2 in vivo in yeast. The interaction was verified by conducting in vitro pull down assays in unpublished work. RNA interference of Gmmc11 in cotyledons resulted in loss of Phytophthora resistance. Gmmc11 ...


Multicellular Secretory Trichome Development On Soybean And Related Glycine Gynoecia, R. A. Healy, R. G. Palmer, Harry T. Horner May 2009

Multicellular Secretory Trichome Development On Soybean And Related Glycine Gynoecia, R. A. Healy, R. G. Palmer, Harry T. Horner

Genetics, Development and Cell Biology Publications

Multicellular glandular trichomes form on gynoecia of wild annual Glycine species, annual soybean cultivars, and wild perennial Glycine species. These trichomes occur from the ovary base to the style base and, in perennial species, along the style as well.Trichomes form at least 2 d before anthesis, and new trichomes develop throughout flowering and also on young seed pods. Trichome structure is similar in all taxa examined, usually five to seven linearly arranged cells. Stalk cells with callose walls become highly vacuolate, and their cytoplasms have reduced numbers of Golgi bodies and endoplasmic reticulum. During secretion, two to four distal ...


Insect-Mediated Cross-Pollination In Soybean [Glycine Max (L.) Merrill]: Ii. Phenotypic Recurrent Selection, Evelyn Ortiz-Perez, Hunt Wiley, Harry T. Horner, William H. Davis, Reid G. Palmer Jul 2008

Insect-Mediated Cross-Pollination In Soybean [Glycine Max (L.) Merrill]: Ii. Phenotypic Recurrent Selection, Evelyn Ortiz-Perez, Hunt Wiley, Harry T. Horner, William H. Davis, Reid G. Palmer

Genetics, Development and Cell Biology Publications

Recurrent selection is a method for population improvement which has been used in soybean [Glycine max (L.) Merrill] to modify traits such as grain yield, seed-protein content, seed-oil content, tolerance to iron-deficiency chlorosis, and seed size. Nuclear male-sterility with insect-mediated cross-pollination has been successfully used in recurrent selection schemes in soybean. However, little attention has been given to selection to increase the agronomic performance of male-sterile plants per se. The objective of this study was to evaluate the response of male-sterile lines segregating for male-sterile alleles ms2, ms3, ms6, ms8, and ms9 to phenotypic recurrent selection for increased seed-set after ...


Insect-Mediated Cross-Pollination In Soybean [Glycine Max (L.) Merrill] : I. Agronomic Performance, E. Ortiz-Perez, S. R. Cianzio, H. Wiley, Harry T. Horner, W. H. Davis, R. G. Palmer Jan 2007

Insect-Mediated Cross-Pollination In Soybean [Glycine Max (L.) Merrill] : I. Agronomic Performance, E. Ortiz-Perez, S. R. Cianzio, H. Wiley, Harry T. Horner, W. H. Davis, R. G. Palmer

Genetics, Development and Cell Biology Publications

In soybean, manual cross-pollination to produce large quantities of F1 hybrid seed for yield trials is difficult and time-consuming. Conversely, insect-mediated cross-pollination has been shown to produce large quantities of hybrid seed in soybean and could facilitate the identification of heterotic patterns. The objective of our study was: (1) evaluate F1hybrid soybean plants from single crosses for yield and agronomic traits over several environments and (2) compare hybrid performance of the single crosses to lines developed from three-way crosses and backcrosses. In 2003, F1 seed of single-crosses and their parent lines were evaluated in replicated experiments ...


Insect-Mediated Seed-Set Evaluation Of 21 Soybean Lines Segregating For Male Sterility At 10 Different Loci, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer Dec 2006

Insect-Mediated Seed-Set Evaluation Of 21 Soybean Lines Segregating For Male Sterility At 10 Different Loci, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer

Genetics, Development and Cell Biology Publications

The first requirement to establish a successful hybrid soybean program is the availability of a stable male-sterile, female-fertile system. Male sterility has been an important tool in soybean breeding programs to improve traits such as yield, seed-protein and seed-oil content, and seed size. However, improvement of seed-set per se on male-sterile plants has not been an important breeding objective. The evaluation of the out-crossing potential of the available male-sterile, female-fertile soybean lines is crucial to determine the future of hybrid soybean. The objective of this study was to evaluate seed-set among 21 soybean lines segregating for male sterility at 10 ...


Evaluation Of Insect-Mediated Seed Set Among Soybean Lines Segregating For Male Sterility At The Ms6 Locus, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer Jun 2006

Evaluation Of Insect-Mediated Seed Set Among Soybean Lines Segregating For Male Sterility At The Ms6 Locus, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer

Genetics, Development and Cell Biology Publications

Currently, there is no economical way to produce large quantities of F1 hybrid soybean seed in the USA. One of the fundamental requirements for hybrid seed production is the availability of a stable male-sterile, female-fertile system. However, the more challenging barrier is the efficient transfer of pollen from the male parent to the female parent. This could potentially be achieved through pollinator insects. Our observations suggested that seed set on male-sterile, female-fertile plants is a good indicator of insect attraction. The objective of this study was to evaluate seed set among male-sterile, female-fertile lines segregating for male-sterile, female-fertile ms6 ...


Light Is Essential For Degradation Of Ribulose-1,5-Bisphosphate Carboxylase-Oxygenase Large Subunit During Sudden Death Syndrome Development In Soybean, J. Ji, M. P. Scott, M. K. Bhattacharyya Jan 2006

Light Is Essential For Degradation Of Ribulose-1,5-Bisphosphate Carboxylase-Oxygenase Large Subunit During Sudden Death Syndrome Development In Soybean, J. Ji, M. P. Scott, M. K. Bhattacharyya

Agronomy Publications

Fusarium solani f. sp. glycines (Fsg) has been reported to produce at least two phytotoxins. Cell-free Fsg culture filtrates containing phytotoxins have been shown to develop foliar sudden death syndrome (SDS) in soybean. We have investigated the changes in protein profiles of diseased leaves caused by cell-free Fsg culture filtrates prepared from Fsg isolates. Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) was conducted to investigate the protein profiles of diseased and healthy leaves. An approximately 55 kDa protein was found to be absent in diseased leaves. Matrix-assisted laser desorption-ionization time-of-flight mass spectrometric analyses and a database search revealed that the ...


A Microscopic Study Of The Trichomes On Gynoecia Of Normal And Tetraploid Clark Cultivars Of Glycine Max And Seven Near Isogenic Lines, Rosaria A. Healy, Harry T. Horner, Theodore B. Bailey, Reid G. Palmer May 2005

A Microscopic Study Of The Trichomes On Gynoecia Of Normal And Tetraploid Clark Cultivars Of Glycine Max And Seven Near Isogenic Lines, Rosaria A. Healy, Harry T. Horner, Theodore B. Bailey, Reid G. Palmer

Genetics, Development and Cell Biology Publications

The surfaces of gynoecia of Glycine max cultivars—normal Clark, a tetraploid Clark, and seven isolines—display variations in at least three types of trichomes. The normal Clark soybean gynoecium has at least three and possibly four types of trichomes: a two‐ to four‐celled, elongate, thick‐walled trichome (TWT), an elongate thin‐walled unicellular trichome (UCT), a secretory multicellular trichome (MCT), and an elongate thin‐walled bicellular trichome that we have interpreted as an immature TWT. All these types are present on the gynoecium by 1 d before anthesis. After fertilization, the UCT is rare, but the other types ...


Floral Nectary Fine Structure And Development In Glycine Max L. (Fabaceae), Harry T. Horner, Rosaria A. Healy, Teresa Cervantes-Martinez, Reid G. Palmer Sep 2003

Floral Nectary Fine Structure And Development In Glycine Max L. (Fabaceae), Harry T. Horner, Rosaria A. Healy, Teresa Cervantes-Martinez, Reid G. Palmer

Botany Publication and Papers

Floral nectaries of annual cultivated Glycine max develop between the bases of the central gynoecium and lateral stamen ring. Each discoid nectary forms immediately before flower opening and degenerates within 24 h. Three stages of nectary development are identified: preactive, active, and postactive. Preactive and active nectaries are composed of a single-layered epidermis that contains many open stomata, with guard cells having thickened walls, starch-engorged plastids, and other organelles. The major portion of each nectary consists of thin-walled special parenchyma cells, each having dense cytoplasm with a nucleus, Golgi bodies and vesicles, mitochondria, plastids, endoplasmic reticulum, many ribosomes, and one ...


Genetics And Cytology Of A New Genic Male-Sterile Soybean [Glycine Max (L.) Merr.], Wei Jin, Harry T. Horner, Reid G. Palmer Feb 1997

Genetics And Cytology Of A New Genic Male-Sterile Soybean [Glycine Max (L.) Merr.], Wei Jin, Harry T. Horner, Reid G. Palmer

Botany Publication and Papers

Genetic and cytological studies were conducted with a new male-sterile, female-fertile soybean [Glycine max (L.) Merr.] mutant. This mutant was completely male sterile and was inherited as a single-recessive gene. No differences in female or male gamete transmission of the recessive allele were observed between reciprocal cross-pollinations in the F1 or F2 generations. This mutant was not allelic to any previously identified soybean genic male-sterile mutants: ms1, ms2, ms3, ms4, ms5, or ms6. No linkage was detected between sterility and flower color (W1 locus), or between sterility and pubescence color (T1 locus). Light microscopic and cytological observations of microsporogenesis in ...


Mycorrhizal Fungi-Bradyrhizobium-Soybean Tripartite Symbiosis In Iowa Soils , Samina Khalil Jan 1991

Mycorrhizal Fungi-Bradyrhizobium-Soybean Tripartite Symbiosis In Iowa Soils , Samina Khalil

Retrospective Theses and Dissertations

Soybean [Glycine max (L.) Merr.] makes use of two important symbiotic microbial systems: the rhizobial system, in which Bradyrhizobium japonicum fix atmospheric N2 in root nodules, and the vesicular-arbuscular mycorrhizal system, in which VAM fungi increase uptake of phosphate and/or other nutrients from the soil or improve plant drought tolerance. Research has confirmed the advantage of bradyrhizobial and mycorrhizal associations in N and P deficient soils; however, these associations may be inhibitory, or have little effect on plant growth in well-fertilized soils. In Iowa over the past 30-40 years, farmers have been adding large quantities of fertilizers to get ...


Effect Of Growth Regulators On Reproduction In Soybeans , Howard A. L. Greer Jan 1964

Effect Of Growth Regulators On Reproduction In Soybeans , Howard A. L. Greer

Retrospective Theses and Dissertations

No abstract provided.


Floral Induction In Soja Max , John Edwin Fisher Jan 1953

Floral Induction In Soja Max , John Edwin Fisher

Retrospective Theses and Dissertations

No abstract provided.


Translocation In Soybean Plants , Leo Preston Vernon Jan 1951

Translocation In Soybean Plants , Leo Preston Vernon

Retrospective Theses and Dissertations

No abstract provided.