Theses and Dissertations at Montana State University (MSU)

Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733

Browse

Search Results

Now showing 1 - 10 of 169
  • Thumbnail Image
    Item
    Gene expression effect on pea protein accumulation
    (Montana State University - Bozeman, College of Agriculture, 2024) KC, Shreejana; Chairperson, Graduate Committee: Kevin McPhee; This is a manuscript style paper that includes co-authored chapters.
    Pea (Pisum sativum L.) is a good source of plant-based protein with important components like globulin, albumin, legumin(11S), prolamin, vicilin(7S), convicilin(8S) and gluteins. It possesses the functional properties like water solubility, hydration, oil holding capacity essential for the formulation of industrial products like Ripptein and protein powder. The study presents an environmental and phenotypic evaluation of pea accessions aimed at estimating the gene expression effect on pea protein accumulation. Understanding gene expression patterns associated with pea protein accumulation is vital to successful crop breeding and plant protein use. Factors impacting breeding and use include gene regulation, developmental biology, environmental factors, and agricultural practices. The experimental design included 300 Plant Identification accessions and four repeated checks planted in an augmented randomized complete block design (RCBD) with one replication in 2021 and two replications in 2022. Phenotypic evaluations included yield, plant height, pod characteristics, and protein content. PI 193837 had the greatest yield (2344 kg/ha) in 2021 and PI 193837 recorded highest yield (3676 kg/ha) in 2022. The average yield was 1536 kg/ha in 2021 and 1867 kg/ha in 2022. PI 269777 PSP had the greatest protein content (36.5%) in 2021 followed by PI 269802 PSP (36.3%) and the average protein content was 25%. In 2022, protein percentage was slightly decreased with PI 404225 PSP having 34% protein. Yield and protein content were significantly correlated (r=-0.2, p = 4.54e -10). Molecular analysis revealed differential gene expression patterns associated with pea protein accumulation, highlighting potential candidate genes and pathways. 456 significant genes were identified. Gene Ontology reveals protein synthesis and translation, stress response, transport function, carbon, propanoate metabolism and glycolysis- gluconeogenesis pathways associated with significant genes. 33 genes associated with storage seed protein in peas was identified. The identified genes and pathways help for genetic manipulation and breeding strategies to enhance nutritional content and functional properties for pea and other leguminous plants.
  • Thumbnail Image
    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.
  • Thumbnail Image
    Item
    Biochemical, physiological, and genetic investigations of multiple herbicide resistant Avena fatua L.
    (Montana State University - Bozeman, College of Agriculture, 2023) Wright, Lucas Arlin; Chairperson, Graduate Committee: William Dyer; Barbara K. Keith (co-chair)
    Intense herbicide usage has led to the evolution of herbicide resistant weeds, which threaten food production and security. The multiple herbicide resistant (MHR) Avena fatua (wild oat) lines investigated here are resistant to all members of selective herbicide families available for A. fatua control. The research in this thesis is designed to help understand some of the ecological, biochemical, and genetic aspects of MHR. First, MHR lines with elevated volatile organic compound (VOC) levels and herbicide susceptible lines were used to compare the feeding behavior of Spodoptera exigua (beet armyworm), and potential role of VOCs to mitigate herbicide injury. Results for feeding behavior were mixed, possibly being influenced by environmental and genetic changes more than VOCs. Exposing VOCs to A. fatua lines found that linalool reduced flucarbazone injury of HS plants, while a combined VOC treatment generally increased herbicide injury. MHR responded differently than HS plants to some treatments, suggesting that MHR has fundamental VOC perception alterations. Other studies compared plant pigments and energy management capabilities and showed that MHR lines had higher beta-carotene and chlorophyll b concentrations, as well as enhanced photosynthetic and excess energy management capabilities in MHR lines. Finally, two populations of recombinant inbred lines (RILs) were phenotyped for herbicide resistance and used to discover several quantitative trait loci (QTL) associated with resistance. Overall, this work contributes to our understanding of MHR and will lay the groundwork for future studies.
  • Thumbnail Image
    Item
    Effects of time, cultivar, and storage environment on winter squash in semiarid Montana
    (Montana State University - Bozeman, College of Agriculture, 2023) Sheild, Victoria Marie; Chairperson, Graduate Committee: Mac Burgess
    Winter squash can be stored for months after harvest while taste, texture, and color attributes improve. The potential for producers to attain greater storage longevity and produce better squash would benefit farmers, consumers, and economies. Due to variation in local climates and the respective vendors' needs, understanding how to control a storage environment can be challenging. This research looks at how storage environment and storage period affect biochemical and physical attributes of ten varieties of winter squash in a semiarid climate. The varieties include three Cucurbita pepo, one Cucurbita moschata, one Cucurbita maxima x moschata hybrid, and five Cucurbita maxima cultivars. Two storage environments were used for analysis. One was located indoors and cooled to 53 degrees F while the other was built into an existing barn with a heating unit and insulation to keep the temperature above freezing. A total of 240 winter squash were placed in each storage space. A completely randomized design was used to assign categorical treatments of storage time to each winter squash, with six levels of treatment being implemented. Each variety of squash (n=4) was analyzed monthly in each storage environment for changes in soluble solids, dry matter, starch content, interior color and exterior color (using CIELAB color values L*, a*, b*), and mass. The temperature and relative humidity of each storage environment were also monitored and recorded hourly during the same period. Cultivar was always the most significant factor. There was no simple effect of the storage environment on dry matter, soluble solids, starch content, or mass. There was a strong significant interaction observed between time and cultivar for each response variable, which shows us that the type of squash and how long it should be stored for are important when discussing quality. Storage did have a significant effect on the a* value of interior color, which is an indicator of quality and nutritional value. The biochemical and physical attributes of each cultivar analyzed varied greatly in its response to the amount of time in storage which in turn influences the taste, texture, and sensory quality of each cultivar uniquely.
  • Thumbnail Image
    Item
    Natural variation in camelina nitrogen responses
    (Montana State University - Bozeman, College of Agriculture, 2023) Gautam, Shreya; Chairperson, Graduate Committee: Chengci Chen; Chaofu Lu (co-chair)
    Camelina (Camelina sativa L.Crantz) is an oilseed crop with the potential to be planted for biofuel production. It is crucial to select camelina genotypes with higher nitrogen use efficiency (NUE) so that the superior cultivar has higher crop productivity. To select genotypes of camelina that exhibit higher biomass yield and nitrogen use efficiency, two field experiments were conducted in 2021 and 2022 in Sidney, MT with different nitrogen regimes, low (unfertilized) and high (fertilized). Distinct projects were carried out, one of them emphasizing canopy area and normalized difference vegetation index (NDVI), and the other focusing on biomass yield and NUE. The experiments highlighted the response of camelina to nitrogen application and the variation among genotypes. The study identified canopy image analysis effectively differentiated the canopy size and growth rate of camelina genotypes under two nitrogen regimes, demonstrating the influence of nitrogen on camelina growth. The NDVI measurement proved to be useful in evaluating plant health and greenness, offering a time-saving and efficient approach. Additionally, some of the genotypes were identified that exhibited high canopy area, NDVI, and nitrogen use efficiency in both 2021 and 2022, providing potential for enhancing crop productivity. This study reveals the potential to use canopy area, NDVI for biomass yield and nitrogen use efficiency screening in camelina.
  • Thumbnail Image
    Item
    Evaluating the genetic and phenotypic responses of Camelina sativa to heat stress
    (Montana State University - Bozeman, College of Agriculture, 2023) Smith, Brian Edward; Chairperson, Graduate Committee: Chaofu Lu
    Camelina sativa (L.) Crantz is a low-input oilseed crop with a unique fatty acid profile in its seed oil. Camelina oil can be used in biodiesels, jet fuels, and industrial lubricants. Improving the abiotic stress tolerance of camelina is a crucial step for increasing agronomic viability. Climate change is threatening production of camelina with rising global temperatures and shorter growing seasons. Elucidating the phenotypic and genetic responses to high temperatures is essential for successful breeding of heat tolerant camelina varieties. Three experiments were conducted to understand these responses. Two genotypes, Suneson (MT5) and Pryzeth (MT102) were exposed to a transient 14-day heat stress during the reproductive stage and evaluated for agronomic and seed quality traits along the main stem. Next, a mapping population consisting of 257 recombinant inbred lines (RILs) were grown under the same temperature regimes for 14 days beginning at the onset of the reproductive stage. Finally, reproductive tissues undergoing heat stress from two genotypes with contrasting heat responses, RIL23 and RIL167, were examined with RNA sequencing, and the phenotypes along the main stem were compared. From the phenotype evaluation, both MT5 and MT102 were significantly impacted by heat. Both genotypes experienced reductions in seed and pod size, seed weight, and total oil contents. As reported in other oilseed crops, camelina is negatively affected by heat, characterized primarily by lower yield and reduced oil content. The QTL analysis identified several key gene regions with co-located traits on chromosomes 8, 10, and 12. This demonstrates the ability to identify heat-responsive gene regions via phenotyping along the main stem. The transcriptomes of RILs 23 and 167 contrasted in both sampled tissue types, with RIL23 appearing more responsive to heat. Phenotypic analysis of these genotypes confirmed the transcriptional differences, as RIL23 was more resistant for several traits associated with fertility. These studies provide resources and protocols for future studies that may assist in improving the heat-tolerance of camelina.
  • Thumbnail Image
    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. Giroux
    The 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.
  • Thumbnail Image
    Item
    Photoperiodic responses of Cannabis sativa: developmental and molecular aspects
    (Montana State University - Bozeman, College of Agriculture, 2022) Avci, Burak; Chairperson, Graduate Committee: Jennifer A. Lachowiec
    The timing of reproductive development is influenced by photoperiod (daylength) in many plants, including Cannabis sativa. However, the developmental and molecular details and the variability of photoperiodic responses in C. sativa are not well understood. I evaluated the photoperiod sensitivity of four high-CBD drug-type Cannabis varieties for four stages of reproductive development by comparing the timing of each stage between plants that received different periods of long-day (LD) exposure prior to the short-day (SD) treatment. In addition, I looked at the influence of photoperiod on the duration between different stages of development, and the effect of plant age on photoperiod sensitivity. The timing of each stage, including the induction of solitary flowers and anthesis was accelerated in 'Eden' under SD conditions. 'Grape Indica' started developing inflorescences in 6 weeks under LD, but the process was also faster when SD treatment began earlier. The development of 'Auto Pivot', on the other hand, was slightly delayed under SD, but each stage occurred with a consistent number of leaves in all treatments. 'Russian Auto' had a shorter juvenile phase and showed accelerated inflorescence development under SD, but earlier stages were not accelerated even though SD development happened with fewer leaves at each stage. Also, older plants responded to SD slightly earlier, especially compared to plants directly started in SD. These results suggest there are important differences between C. sativa varieties in terms of the timing and the process of reproductive development, even within the day-neutral/auto-flowering varieties. I identified four FLOWERING LOCUS T (FT)-LIKE genes in the Cannabis genome and analyzed their diurnal expression patterns in 'Eden' and 'Auto Pivot' under LD and SD. FTL2 showed a similar expression pattern to FT genes that are known to induce flowering in other SD species, and the expression in photoperiod-sensitive variety, Eden, was different between photo-period treatments, while it was mostly unaffected in the day-neutral variety, Auto Pivot, suggesting FTL2 could be a potential photoperiod-regulated floral promoter in C. sativa.
  • Thumbnail Image
    Item
    The impact of Teosinte branched1 and reduced height mutations in durum wheat
    (Montana State University - Bozeman, College of Agriculture, 2021) Brown, McKenna Margaret; Chairperson, Graduate Committee: Michael J. Giroux
    Increasing the yield of wheat requires identifying new genetic combinations of alleles by crossing or by creating variation in yield limiting genes. Wheat yield is impacted by tiller number and seeds per tiller, both of which are impacted by the Reduced height (Rht) and Teosinte branched1 (TB1) genes. In this study, durum plants varying for Rht and TB1 alleles created by EMS mutagenesis were studied to determine the impact of each allele upon agronomic and seed traits. Both projects aimed to increase durum yield, one through an increase in tiller number; the other through the development of a plant with height between current full-height and semi-dwarf varieties that can allocate more resources to seed production. The impact of TB1 null alleles were studied alone and together in greenhouse and field trials, along with an RNA sequencing study to determine the impact of TB1 mutation upon global gene expression in developing meristems. TB1 single and double null mutants produced more biomass and tillers per plant, and expression of genes in meristems varied. A screen of wheat varieties grown in Montana identified that several spring and durum wheat varieties contain different TB1 alleles, but none contained TB1 null alleles. Rht experiments included field trials, coleoptile length and gibberellic acid responsiveness assays, and an in-vitro test to determine the impact of each Rht mutation upon binding to Gibberellin Interacting Domain 1 (GID1) that directly influences plant height. It was found that the previously described Rht-B1b-E529K allele reduced both plant height and coleoptile length while two newly characterized Rht mutations had lesser impacts with trends towards intermediate-height plants. The results of this research demonstrate that Rht alleles that alter RHT binding to GID1 and TB1 null alleles may prove useful in increasing durum tillering and optimizing plant height for different growing conditions.
  • Thumbnail Image
    Item
    Chickpea variety evaluation and intercropping for disease management and yield
    (Montana State University - Bozeman, College of Agriculture, 2022) Zhou, Yi; Chairperson, Graduate Committee: Chengci Chen; This is a manuscript style paper that includes co-authored chapters.
    Chickpea (Cicer arietinum L.) is an important food grain legume, but production is constrained by the soilborne pathogen complex, Ascochyta rabiei, and the development of fungicide resistance. Cultivar resistance is one of the most efficient strategies in disease management. However, chickpea cultivars with resistance to soilborne pathogens or complete resistance to A. rabiei have not been developed. Intercropping chickpea-flax has the potential for Ascochyta blight management. To minimize the impact of soilborne disease and Ascochyta blight on chickpea production, refining of integrated pest management practices is essential. To evaluate the effect of cultivar selection in combination with seed treatment on soilborne disease control, twenty-five cultivars/lines were planted with or without fluxapyroxad, pyraclostrobin, and metalaxyl under field conditions. The area under disease progress curve (AUDPC), seed yield, and protein content were assessed. Fusarium solani was isolated and identified in the late season, and the disease severity of root rot was evaluated. The results showed that seed treatment effectively suppressed damping-off and improved chickpea yield but only slightly reduced late-season root rot. The AUDPC of NDC160166 and NDC 160236 was not significantly reduced by seed treatment, which could be a future resource of resistance. To assess the effects of configurations and resistant cultivar on yield and Ascochyta blight management in intercropping chickpea-flax, two chickpea cultivars (CDC Leader and Royal) were planted with flax under six configurations (monocrop chickpea, 70% chickpea-30% flax in mixture, 50% chickpea-50% flax in mixture, 50% chickpea-50% flax in alternate rows, 30% chickpea-70 flax in mixture, monocrop flax). Yield and nutrient content of component crops and Ascochyta blight infection were evaluated. Chickpea yield decreased as flax proportion increased in the mixture. Chickpea yielded higher in the alternate row design than in the mixture at the same seeding rate due to less interspecies competition in the alternate rows. Intercrop increased 2%-23% land productivity. Chickpea-flax intercrop effectively reduced Ascochyta blight under higher disease pressure. The configuration of 50% chickpea and 50% flax in the mixture was more effective in suppressing Ascochyta blight than in the alternate row configuration. Integrated resistant cultivar and intercropping configuration was most effective in disease suppression.
Copyright (c) 2002-2022, LYRASIS. All rights reserved.