Theses and Dissertations at Montana State University (MSU)
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Item Multi-environment evaluation of winter pea genotypes for winter survival and yield stability(Montana State University - Bozeman, College of Agriculture, 2024) Poudel, Amrit; Chairperson, Graduate Committee: Kevin McPhee; This is a manuscript style paper that includes co-authored chapters.Winter pea can be grown as a rotational crop for soil moisture conservation and nutrient recycling in the wheat-growing region of Montana. Development of winter hardy cultivars would increase seed yield and expand the area of adaptation of this crop. Harsh winter conditions present a significant challenge to the production of winter peas. The objective of this study was to screen pea germplasm and breeding lines for winter survival and identify genotypes with good winter hardiness for future crop production. Field trials were conducted to evaluate genotypes at Bozeman, Havre, Huntley, and Moccasin, MT in 2021, 2022, and 2023. These lines included elite winter cultivars and several checks. Winter hardiness was evaluated as the percentage of surviving plants and by agronomic performance including yield. Genotypes were evaluated based on the GGE biplot method. This analysis captured multiple variables including yield, protein content, seed size, and their overall stability across multiple years and locations of study to aid in selecting lines. Differential winter survival was observed across locations and years. Higher winter survival was seen in Bozeman and Havre. Few lines were identified as having high seed yield and stable production over years and locations. Breeding lines had higher mean yield with few good lines having stable production of greater than 2500 kg/ha. Germplasm lines showed better winter survival than breeding lines. Protein content ranged from 20% to 31%. Larger seeds were observed in Moccasin, whereas Havre had the highest protein content. Mega- environment differentiation helped to select specific genotypes based on the trait of interest for a particular environment. Several European and US lines used in the experiments having high winter hardiness record performed better for seed yield and resistance to stress. The lines identified as having high levels of cold tolerance can be used as a prospective genetic resource in pea breeding programs. Genotypes having high and stable seed yield can be considered for release as a variety and made available to producers.Item Consider the roots: examining barley belowground in the search for adaptation(Montana State University - Bozeman, College of Agriculture, 2024) Williams, Jessica Lynn; Chairperson, Graduate Committee: Jamie Sherman; This is a manuscript style paper that includes co-authored chapters.Barley is important for global food security and sustaining the economically valuable malt industry. Montana is a top barley producer in the United States, but terminal drought stress poses a significant threat to this production by negatively impacting yield and quality. New crop varieties with enhanced environmental adaptation and soil resource extraction would help address this and other issues facing modern agriculture. Stay-green is a trait that extends grain fill in cereals and can stabilize yield and quality under drought. However, this trait and its benefits can be inconsistent across environments and its successful incorporation into breeding strategies would benefit from expanded understanding of stay-green. Roots may play a role in stay-green physiology. Roots provide plants with the water and nutrients needed for growth and are important for crop performance in their own right. Different root system architectures provide adaptation to different environmental stressors, but studying these belowground structures is challenging. Adaptation is also impacted by soil properties and microbial communities. For this dissertation, roots were examined in greenhouse seedling assays and field trials in Montana. Agronomic performance was also assessed for malt barley and spring wheat cultivars varying for stay-green, a biparental barley population segregating for stay-green, and a diverse mapping population of barley lines from different breeding programs. Stay-green cultivars had a greater percentage of deep roots, more prolonged root growth during grain fill, and greater yield. Analysis of the biparental population identified genetic co-segregations of stay-green, root phenotypes, grain quality, and quality stability between environments, further supporting the benefit of stay-green in dry environments and its connection to roots. The diverse mapping population was used to find associations between the relative abundances of bacteria in the rhizosphere and barley genetic loci, that were mostly environment specific. Rhizospheric bacteria may be involved in local adaptation of plants. Finding plant genetic signal for these microbial characteristics supports the idea that it may be possible to breed crops with enhanced ability to recruit beneficial microbiomes if environmental influence and agronomic impact can be understood. Root examination remains a challenging but worthwhile avenue to pursue in crop adaptation research.Item Characterization and testing of reduced height (RHT) hypomorphs in durum and spring wheat(Montana State University - Bozeman, College of Agriculture, 2023) Ugrin, Josey Mackinsey; Chairperson, Graduate Committee: Michael J. GirouxThe Reduced Height (Rht) gene in wheat (Triticum aestivum L.) increases yield by partitioning less nutrients to stem elongation and more towards spike development. In hexaploid wheat, the mutations Rht-B1b and Rht-D1b, create high-yielding semi-dwarf varieties. While Rht-B1b and Rht-D1b have been widely adopted due to their ability to increase yield, they also have drawbacks such as smaller seed size and lower protein content. Furthermore, tetraploid durum wheat (Triticum. turgidum L), Rht-B1b creates plants that are shorter than in hexaploid wheat under Northern Great Plains growing conditions. This project aimed to further characterize Rht and to develop a plant height intermediate between current standard-height and semi-dwarf varieties to increase yield in both durum and spring wheat. To create novel Rht alleles, seeds were mutagenized with Ethyl-methanesulfonate (EMS) and mutations were identified. Near-isogenic lines (NILS) were developed for the two Rht-A1 alleles and Rht-B1b-E529K alleles in semi-dwarf (Rht-B1b) and standard height (Rht-B1a) varieties in durum. In spring wheat, NILs were developed for eight Rht-A1 alleles in two high-yielding Montana varieties. These NILS were planted in field trials and plant height and grain traits were measured. Four novel mutations, Rht-A1-E63K, Rht-A1-Q6*, Rht-A1-V55M, and Rht-A1-53T in spring wheat and two mutations in durum, Rht-B1b-E529K and Rht-A1-S50F all had either significantly changed height or grain traits. Along with developing and testing Rht alleles for field trait improvement, we did a study to characterize an Rht stop-codon dosage response in wheat. Previous studies in rice and barley have indicated that a lack of the functional SLR1/SLN1 gene respectively, results in an abnormal growth response characterized by taller height and slender appearance. This effect on Rht function has yet to be tested in wheat. Rht nonsense alleles were created by screening an EMS treated population created using seed of a standard-height Montana variety. We combined mutations creating lines homozygous for single, double, or triple mutations. In field trials, Rht triple mutants exhibited a slender, elongated phenotype with strike heads similar to SLN1 mutants in barley. Differences in height varied for the other crosses but did trend towards increased height with increased Rht-stop mutation dosage.Item Improving malt barley agronomics via allelic selection of senescence and flowering time controlling genes(Montana State University - Bozeman, College of Agriculture, 2020) Alptekin, Burcu; Chairperson, Graduate Committee: Andreas M. Fischer; Dylan Mangel, Duke Pauli, Tom Blake, Jennifer Lachowiec, Traci Hoogland, Andreas Fischer and Jamie Sherman were co-authors of the article, 'Combined effects of glycine-rich RNA binding protein and a NAC transcription factor extend grain fill duration and improve malt barley agronomic performance' submitted to the journal 'Theoretical and applied genetics' which is contained within this thesis.; Dylan Mangel, Duke Pauli, Tom Blake, Jennifer Lachowiec, Jamie Sherman and Andreas Fischer were co-authors of the article, 'Dissecting the effects of senescence-regulating HvNAM1 and HvNAM2 transcription factors on malt barley agronomics' submitted to the journal 'Molecular breeding' which is contained within this thesis.; Dylan Mangel, Duke Pauli, Tom Blake, Hannah Turner, Jennifer Lachowiec, Jamie Sherman and Andreas Fischer were co-authors of the article, 'Allelic selection of senescence and flowering time controlling genes confers malt extract stability' submitted to the journal 'Journal of the American Society of Brewing Chemists' which is contained within this thesis.Malt barley (Hordeum vulgare L.) is a high-profit crop for farmers; yet, its production raises challenges that need to be addressed. The standards for grain quality in malt barley are stringent, and the rejection of non-qualified grains by maltsters is the leading cause of revenue loss for malt barley producers. Rejection is mainly due to high grain protein content and low kernel plumpness which both cause significant problems in the malting process. While proper growing practices can improve malt quality, the industry requires genotypes that have more stable malt quality. Therefore, understanding the molecular mechanisms associated with grain quality can be applied to improve selection of superior malt varieties. A considerable volume of literature has suggested that regulation of whole-plant senescence and flowering processes in cereals have direct influences on grain yield and quality parameters. The central question in this dissertation examined whether malt barley agronomic and end use quality can be improved by the selection of varying alleles for genes associated with plant development. With this purpose, two whole-plant senescence-regulating NAM, ATAF and CUC (NAC) transcription factors, HvNAM1 and HvNAM2, and a flowering-time controlling Glycine-Rich RNA Binding Protein (HvGR-RBP1) were studied. Molecular markers for selection of alleles from varieties 'Karl' (with consistently low grain protein) and 'Lewis' were developed, and an advanced-generation malt barley breeding population was genotyped. Statistical analysis of growth parameters from this population showed that selection of HvNAM1 'Karl', HvNAM2 'Karl' and HvGR-RBP1 'Lewis' alleles ensures a longer grain filling period in malt barley. Plants with prolonged grain filling also exhibited increased kernel plumpness and test weight. Additionally, selection of 'Karl' alleles for both NAC genes decreased grain protein content ensuring grain quality for malting. The improvement of grain characteristics correlated with improved malt phenotypes, for example a ~2% increase in malt extract, and improvement in other malt characteristics such as beta-glucan content and alpha-amylase activity was observed. Overall, these data show that molecular genetics and allelic selection for genes controlling plant development is promising for advancing malt quality. Research performed here has a direct potential for improving the profits for malt barley producers.Item Characterization and identification of novel reduced height (RHT-1) alleles in wheat(Montana State University - Bozeman, College of Agriculture, 2019) Jobson, Emma Marie; Chairperson, Graduate Committee: Michael J. Giroux; M.J. Giroux, J.M. Martin, R.E. Johnston and A.J. Oiestad were co-authors of the article, 'The impact of the wheat RHT-B1B semi-dwarfing allele on photosynthesis and seed development under field conditions' in the journal 'Frontiers in plant science' which is contained within this dissertation.; M.J. Giroux, J.M. Martin and T.M. Scheider were co-authors of the article, 'The impact of the RHT-B1B, RHT-D1B, and RHT-8 wheat semi-dwarfing genes on flour milling, baking, and micronutrients' in the journal 'Cereal chemistry' which is contained within this dissertation.; M.J. Giroux, J.M. Martin and J.B. Ohm were co-authors of the article, 'RHT-1 semi-dwarfing alleles alter dough rheology by modifying gluten composition' submitted to the journal 'Cereal chemistry' which is contained within this dissertation.; M.J. Giroux, J.M. Martin and A.C. Hogg were co-authors of the article, 'Identification and molecular characterization of novel RHT-1 alleles in hard red spring wheat' submitted to the journal 'Crop science ' which is contained within this dissertation.Since their introduction in the 1960s, the semi-dwarfing Reduced Height (Rht-1) genes in wheat have been incorporated into the majority of modern wheat varieties. Their popularity has been driven by their positive impact on yield. The two most common semi-dwarfing alleles, Rht-B1b and Rht-D1b, reduce height ~20% and increase yield ~6% compared to tall varieties. Their shorter stature makes them less susceptible to lodging under increased water and nitrogen inputs compared to tall wheat varieties. Despite their prevalence, the exact mechanism by which Rht-B1b/Rht-D1b increase yields is still unknown. Furthermore, very little research has been done to characterize their impact on bread making and end use quality. Finally, beyond Rht-B1b and Rht-D1b, there is very little allelic diversity available to wheat breeders. The objectives of this research were to investigate the impact of Rht-B1b on photosynthesis, characterize the impact of Rht-B1b/Rht-D1b on bread making and dough rheology, and to identify and test novel Rht-1 alleles created using EMS mutagenesis. In regards to photosynthesis: we found Rht-B1b reduces flag leaf photosynthetic rate (18%) and chlorophyll A content (23%) compared to the tall wildtype at anthesis. In regards to end use quality: we found Rht-B1b/Rht-D1b decrease total grain protein content (2%) but increase gluten index (21%), bake mixing time, and bake mixing tolerance compared to the tall lines. Increased gluten index and mixing time in the semi-dwarfing lines was shown to be associated with increased high molecular weight glutenins. In regards to developing novel alleles: we identified three nonsense Rht-1 alleles and characterized their impact on coleoptile length, gibberellin responsiveness, and DELLA/GID1 interaction. Further research will be needed to investigate their impact on agronomic traits and found that each abolished GID1 interaction in the absence but not the presence of Gibberellic acid. Overall this dissertation provides new insight on the impact of the semi-dwarfing alleles on wheat growth and development, wheat milling and baking properties and increases the available allelic diversity through the introduction of three new Rht-1 nonsense alleles.Item Mapping quantitative trait loci to understand seed size variation in Camelina sativa(Montana State University - Bozeman, College of Agriculture, 2019) King, Kevin Allen; Chairperson, Graduate Committee: Chaofu LuCamelina sativa (L.) Crantz is an emerging Brassica oilseed crop. Camelina oil is high in polyunsaturated C18-fatty acids and its uses range from bio-fuels and bio-lubricants to an animal feed additive and cooking oils. A major breeding objective for camelina is to develop varieties with increased seed size. Understanding the genetics behind seed size variation would help breeders develop varieties that are more robust, easier to plant and harvest, better for oil processing, and could increase oil yield. For this study, a genetic linkage map was created and quantitative traits loci (QTL) were identified for eight agronomic traits using a bi-parental recombinant inbred population created between the two Camelina varieties: 'Suneson,' which has an average seed area of 1.35 mm2, and 'Pryzeth' with an average seed area of 2.24 mm2. Field trials were conducted in 2017 and 2018 in both dryland and irrigated treatments in Bozeman, Montana. Significant QTL were discovered for seed size and other agronomic traits measured, including flowering time, pod size, seed weight, and oil content. The results of this study could lead to marker-assisted breeding for varieties better adapted to modern agriculture.Item Impact of the D genome and quantitative trait loci on quantitative traits in a spring bread wheat by spring durum wheat cross(Montana State University - Bozeman, College of Agriculture, 2014) Kalous, Jay Robert; Chairperson, Graduate Committee: Luther E. TalbertDesirable agronomic traits are similar for common hexaploid (6X) bread wheat (Triticum aestivum, 2n = 6x = 42, genome, AABBDD) and tetraploid (4X) durum wheat (T. turgidum durum, 2n = 4x = 28, genome, AABB). However, bread and durum wheat are genetically isolated from each other due to an unequal number of genomes that cause sterility when crossed. Previous work allowed identification of a 6X and 4X parent that when crossed resulted in a large number of recombinant progeny at both ploidy levels. In this study, interspecific recombinant inbred line populations at both 4X and 6X ploidy with 88 and 117 individuals, respectively, were developed from a cross between Choteau spring wheat (6X) and Mountrail durum wheat (4X). Lines within each population contained a mixture of alleles from each parent for loci in the A and B genomes. The presence of the D genome in the 6X population resulted in increased yield, tiller number, and seed size. The D genome also resulted in a decrease in stem solidness, lower test weight and fewer seed per spike. Similar results were found with a second RIL population containing 152 lines from 18 additional 6X by 4X crosses. Several additional QTL for agronomic and quality traits were identified in both the 4X and 6X populations. Positive durum alleles increasing kernel weight in hexaploids, on chromosomes 3B and 7A may be useful for introgression by bread wheat breeders.Item Breeding for root lesion nematode resistance in Montana winter wheat(Montana State University - Bozeman, College of Agriculture, 2015) May, David Bruce, III; Chairperson, Graduate Committee: Philip L. BrucknerRoot lesion nematodes (RLN; Pratylenchus spp.) present a serious challenge to dryland wheat production worldwide. Development of resistant cultivars would provide great economic benefit to growers. From 2012-2013, a set of backcross lines (MT08185//MT08184/Persia 20) was screened twice for resistance to P. neglectus. Progeny and parent lines were grown in infested soil for 16 to 18 weeks. Nematodes were then extracted from roots of individual plants and counted to obtain per plant final populations. ANOVA results from the 2013 screen showed significant differences in mean P. neglectus populations among lines (p < 0.01). The median final population of susceptible parent MT08184 was an estimated 4.9 times greater than that of resistant parent Persia 20. A 2013 field trial in the absence of root lesion nematodes indicated reductions in grain yield, volume weight, and protein were not associated with resistance. Seven RLN-resistant lines were identified in field evaluations with agronomic phenotypes for yield, volume weight and protein comparable to those of five widely-grown checks. Identification of quantitative trait loci (QTL) for resistance to RLN will facilitate marker-assisted introgression of resistance genes in a backcross-breeding program. Single-marker analysis of 218 genome-wide single nucleotide polymorphism markers (SNPs) was performed to identify genomic regions associated with resistance to P. neglectus. The analysis identified putative marker-trait associations on chromosomes 1AL, 1DS, 2BL, 5BL, 5DL, 7AL and 7DL (all p < 0.05). Overall, phenotypic screens as applied were inadequate to consistently characterize wheat lines for RLN resistance. As such, RLN resistance phenotypes and putative QTL effects identified in the study must be verified in future experiments.Item Utilizing lethal translocation homozygotes of barley (Hordeum vulgare L.)(Montana State University - Bozeman, College of Agriculture, 1988) Biggerstaff, Daniel ReidItem Genetic analysis of agronomic and malting quality QTLS in barley backcross breeding populations(Montana State University - Bozeman, College of Agriculture, 1996) Larson, Steven Richard