Theses and Dissertations at Montana State University (MSU)
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Item Characterization and assessing fungicide sensitivity of Fusarium spp. causing root rot and wilt in lentils in the northern Great Plains(Montana State University - Bozeman, College of Agriculture, 2022) Bugingo, Collins; Chairperson, Graduate Committee: Mary Burrows; This is a manuscript style paper that includes co-authored chapters.Fusarium root rot and wilt are yield limiting diseases caused by Fusarium spp. in lentils globally. Seedborne Fusarium species and races of Fusarium oxysporum f. sp. lentis (Fol) have not been characterized. The sensitivity of commonly used fungicides on prevalent species is not fully known. In 2019 and 2020 commercial lentil fields were surveyed and seed lots collected from infected patches and further isolation, morphological and molecular characterization was conducted in the laboratory. Additional isolates and lentil seed were received from Washington, Montana, Idaho, North Dakota, southern Canada, and Spain for fungicide, seedborne Fusarium spp. and race-characterization of Fol respectively. In addition to assessing presence of seedborne Fusarium pathogens on the seed coat, the cotyledon and embryo were assessed for the presence of Fusarium spp. Fungicide sensitivity was assessed using mycelial assays and an additional spore assay for pyraclostrobin. A total of 84 seed lots from the Northern Great Plains (NGP) were assayed where a total of 486 and 228 Fusarium isolates were isolated in 2019 and 2020, respectively and all the representative isolates were virulent with a 1.5-4.5 root rot severity rating. Most isolates were found in the seed coat (57- 75%), cotyledon (19-23%) and embryo (6-20%) for the 2019 and 2020 isolates, respectively. F. oxysporum and F. acuminatum were all either sensitive or intermediately sensitive to prothioconazole and ipconazole. A total of 51 isolates were race-typed and 9 races identified whereby race 7 and 1 were the predominant at 53% and 16%, respectively. This study underscores the importance of understanding Fusarium spp. composition in lentil production, role of seedborne inoculum, fungicide efficacy in root rot/wilt management and race composition upon developing effective Integrated Pest Management (IPM) strategies.Item Genetics of seed dormancy in wheat and barley(Montana State University - Bozeman, College of Agriculture, 2020) Vetch, Justin Michael; Chairperson, Graduate Committee: Michael J. Giroux; Robert N. Stougaard, John M. Martin and Michael J. Giroux were co-authors of the article, 'Revealing the genetic mechanisms of preharvest sprouting' in the journal 'Plant science' which is contained within this dissertation.; Robert N. Stougaard, John M. Martin and Michael J. Giroux were co-authors of the article, 'Allelic impacts of TaPHS1, TaMKK3, and Vp1B3 on preharvest sprouting of northern Great Plains winter wheats' in the journal 'Crop science' which is contained within this dissertation.; Jason G. Walling, Jamie D. Sherman, John M. Martin and Michael J. Giroux were co-authors of the article, 'Mutations in the HvMKK3 AND HvAlaAT1 genes affect barley pre-harvest sprouting and after-ripened seed dormancy' in the journal 'Crop science' which is contained within this dissertation.; Philip L. Bruckner, John M. Martin and Michael J. Giroux were co-authors of the article, 'TAMFT homeologs are associated with preharvest sprouting winter wheat' submitted to the journal ''Crop science' which is contained within this dissertation.Montana producers have many biotic and abiotic stresses to contend with. One of interest to avoid is preharvest sprouting (PHS), which is the precocious germination of grains before harvest. PHS affected grain is discounted at the elevator, resulting in grain being unsuitable for many foods and direct losses to producers. PHS is not widespread every year in Montana but in some years causes large economic loss. Although PHS is a response to environmental cues it is largely controlled by genetics. Genes that control seed dormancy are the most likely candidate genes for PHS resistance and the series of studies presented in this dissertation examine the impact of several genes upon small grain PHS susceptibility. The studies used several methods to assess PHS susceptibility and determine which alleles of individual genes were present. The methods included seed dormancy screening assays, alpha amylase enzyme activity analysis, falling numbers analysis, genotyping by direct sequencing and via use of various markers, RNA-sequencing, and gene expression analysis. The first study served as a PHS susceptibility survey and provides PHS tolerance information on MT grown wheat varieties. This study also found that of the three most reported PHS associated genes (TaMFT 3A, TaMKK3 4A, and TaVp1 3B), only TaMFT 3A was associated with PHS in Montana winter wheats, even though the previously reported variation was observed in all three genes. The second study looked at PHS susceptibility among current and historically grown barley varieties. It was found that malt varieties vary greatly in their susceptibility to PHS with the top grown AMBA recommended varieties among the most susceptible. It was also found that a previously unstudied mutation in the HvMKK3 gene is associated with PHS susceptibility. Interestingly, HvMKK3 and HvAlaAT1 affect dormancy at different time points in grain maturity indicating dormancy may be tailored to a specific timeframe (high dormancy at harvest with rapid decay of dormancy after harvest). The final study revisited winter wheat PHS and found that the TaMFT 3B and 3D homeologs are associated with PHS which has not been shown to date.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 Genetic exploration of spike and seed morphology in a two-rowed barley nested association mapping panel(Montana State University - Bozeman, College of Agriculture, 2018) Getz, Megan Marie; Chairperson, Graduate Committee: Jamie ShermanBarley (Hordeum vulgare) is unique as it has six-rowed cultivars and two-rowed cultivars. The six-rowed has three fertile florets on each spikelet, while two-rowed has only a single fertile center floret per spikelet. This by itself affects seed uniformity as seed produced in the lateral florets tend to be less symmetrical and smaller in size than the center floret. Yield and plumpness are also affected by spike morphology. While the genes and alleles affecting six-rowed vs. two-rowed spikes are known, there are a number of other genes that affect additional spike morphological traits such as number of seeds per head, length of head, and compaction of spikelets. Here, a two-rowed Nested Association Mapping (NAM) population was used to genetically dissect barley spike and seed morphology. To create the population, 13 diverse founder lines of barley were crossed with Conlon, a high yielding, plump, spring variety. Approximately 80 progenies were selected from each of the Conlon by founder crosses, and then backcrossed to Conlon in hopes of exposing the advantageous traits while adapting lines to the Great Plains of the Northwest. The population varying for spike and seed morphology was grown out in a field trial in Bozeman, MT and Logan, UT where phenotypic data was collected throughout the stages of growth and harvest. At maturity (Zadok's 50) stage five heads from each of the lines were collected. Digital Image Analysis was used to measure spike length, kernel count, density, and seed size. Genetic maps were created for each family as well as a consensus map for the whole population. Associations between the phenotypic data and the genotypic data observed in the individual families and consensus map allowed us to identify QTLs conserved across multiple families as well as unique to individual families. Evidence of pleiotropic effects between traits was observed. Some of the QTLs previously were identified, and some are novel. One of the families was of particular interest due to unique QTLs impacting seeds per spike and seed weight. Additionally, several novel QTLs were identified on chromosome 7H that highly impact seed traits.Item Potato and potato virus Y: the effect of cultivar, seed type, and dfense-inducing agents differences in incidence(Montana State University - Bozeman, College of Agriculture, 2016) Boyd, Elisa Kirk; Chairperson, Graduate Committee: Michelle Flenniken; Eileen Carpenter, Michelle Flenniken and Nina Zidack were co-authors of the article, 'Potato cultivar and seed type affect incidence of potato virus Y (PVY N-WI) infection' submitted to the journal 'Plant disease' which is contained within this thesis.; Eileen Carpenter, Michelle L. Flenniken and Nina Zidack were co-authors of the article, 'Examination of resistance-inducing compounds to limit potato virus Y (PVY N-WI) infection in potatoes' which is contained within this thesis.Potato (Solanum tuberosum subsp. tuberosum) is an important crop grown worldwide. Propagated vegetatively, a sustainable potato industry relies on pathogen free, tissue culture-produced plantlets to maintain low disease incidence in seed potato stock. Potato virus Y (PVY) infection is the most significant threat to seed potato production. Therefore, determining the influence of cultivar and seed type on PVY incidence could lead to improved management practices. Data from seed potato certification inspection in Montana indicated that plants grown from seed produced in sterile conditions (plantlets and minitubers) had a greater incidence of PVY than plants grown from field-produced tubers. We hypothesized that differences in cultivar, seed type and growth conditions (i.e., sterile vs. field grown) impacted PVY incidence. Systemic acquired resistance (SAR) is a plant immune response that is induced by pathogens and resistance-inducing agents. Resistance-inducing agents are effectively used to limit fungal pathogens, and we hypothesized that they may also limit PVY infection. To test these factors, potato plants (cultivars Russet Burbank and Norkotah Colorado 3) were grown from multiple seed types (i.e., plantlet, minituber, and Generation 3 tuber (G3)) and mechanically inoculated with PVY strain Wilga in the presence and absence of Systemic Acquired Resistance (SAR) inducing agents. Percent infection (incidence) was measured with double-antibody sandwich enzyme-linked immunosorbent assay (DASELISA) at three time points post-inoculation. These studies resulted in the following conclusions: (1) incidence of PVY infection varies by cultivar, specifically, the Russet Burbank cultivar had a lower incidence of PVY than the Norkotah Colorado 3 cultivar, (2) Russet Burbank plants grown from tissue culture plantlets had a higher incidence of PVY infection than Russet Burbank plants grown from field-produced G3) tubers, and (3) phosphorous acid (Phostrol®), an inducer of Systemic Acquired Resistance (SAR) may reduce PVY infection, particularly in Russet Burbank plantlets. These findings advance our understanding of the differences in PVY incidence by cultivar and seed type, and in turn provide valuable information for maintaining pathogen free potato seed.Item Increasing harvestability of Phacelia hastata seed using plant growth regulators(Montana State University - Bozeman, College of Agriculture, 2014) Keating, Rosemary Ljung; Chairperson, Graduate Committee: Tracy A. O. DougherPhacelia hastata, an excellent pollinator plant that is highly drought resistant, winter hardy, and tolerant of acid and heavy metal soils, has limited commercial availability due to inadequate seed supplies. Indeterminate flowering, lodging and seed shatter of this species make mechanical seed harvest difficult. This study was undertaken to evaluate the effects of four plant growth regulator formulations (PGRs) on seed yield, seed quality and growth characteristics of P. hastata. These PGRs were gibberellin, paclobutrazol, ethephon, and a hormone compound containing gibberellic acid, cytokinin and indolebutyric acid. In field experiments, foliar sprays of PGRs were applied at two rates and two timings. Plots were sprayed once, at early vegetative stage, or twice, with a sequential spray three weeks later. The exception was ethephon, which was sprayed once at time of full bloom. Treatments included plots sprayed with (1) 100 and 200 ppm gibberellic acid (2) 30 ppm paclobutrazol, (3) 2000 ppm ethephon, (4) 2500 ppm Ascend (a hormone compound consisting of cytokinin, gibberellic acid and indolebutyric acid), and (5) deionized water (Control). Two foliar applications of paclobutrazol, at a rate of 30 ppm, at one-month rosette stage and three weeks later, increased seed yield of P. hastata in thinned plots by 337%. In plots treated with ethephon, seed shatter was eliminated but seed yield and germination decreased. Results suggest foliar sprays of the plant growth regulator paclobutrazol on P. hastata regulate the flowering process, increasing harvestable seed.Item Population improvement of seedling traits in beardless and Altai wildrye (Leymus spp.)(Montana State University - Bozeman, College of Agriculture, 2003) Foster, Neal RobinItem The effects of soil moisture stress on water utilization, seed yield components, and grain and baking quality of selected spring wheat accessions(Montana State University - Bozeman, College of Agriculture, 1988) Bunker, James ReedItem Seed development in shrunken endosperm, high lysine mutants of barley (Hordeum vulgare L.)(Montana State University - Bozeman, College of Agriculture, 1982) Fastnaught, Christine ElizabethItem Relationship between seed vigor tests and field performance in winter and spring wheat (Triticum aestivum L.)(Montana State University - Bozeman, College of Agriculture, 1983) Ram, Chandgi