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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 Seed dormancy and greenhouse propagation of arrowleaf balsamroot (Balsamorhiza sagittata) and silverleaf phacelia (Phacelia hastata var. hastata)(Montana State University - Bozeman, College of Agriculture, 2015) Bujak, Charissa Maria; Chairperson, Graduate Committee: Tracy A. O. DougherNative plant material, defined by the United States Forest Service, includes all indigenous terrestrial and aquatic plant species that evolved naturally in a defined ecosystem. Native plant material is important for horticultural and restoration purposes; however, propagation protocols for many Montana native plant species remains unknown. This study addressed the following: greenhouse propagation, seed dormancy classification, and seed-dormancy release treatments for arrowleaf balsamroot (Balsamorhiza sagittata) and silverleaf phacelia (Phacelia hastata var. hastata). Additionally, an assessment was completed to better understand current challenges, successes of the Montana native plant market. In this study gibberellic acid (GA3) significantly increased final germination of arrowleaf balsamroot to 81% + or = 2%. Utilizing the Baskin and Baskin (1998, 2004) seed dormancy classification scheme, arrowleaf balsamroot seed dormancy was classified as: 1) nondeep physiological dormancy type 2, 2) intermediate physiological dormancy type 2, and 3) deep physiological dormancy type 1 and 3. Following the Schewienbacher (2011) reclassification scheme, arrowleaf balsamroot seeds were indicative of physiological deep dormancy type 3. In the greenhouse, fertilizer rates up to 200 mg nitrogen/L (20-10-20 NPK of Jack's Professional Peat Lite Special TM) resulted in positive shoot growth but beyond 100 mg nitrogen/L reduced the root-to-shoot value. The Ray Leach Cone-tainer TM was an effective container type. For silverleaf phacelia, 87% + or = 5% germination was achieved within four days with scarification for at least 90 seconds. After 1 year of storage at 5 + or = 1°C, following the Baskin and Baskin (1998) classification scheme, silverleaf phacelia seed dormancy was classified as 1) nondeep physiological dormancy type 1, 2, and 5, and 2) intermediate physiological dormancy type 1 and 2. Addressing nondeep physiological dormancy type 5 would be most effective in breaking seed dormancy. In the greenhouse, fertilizer rates beyond 50 mg nitrogen/L (20-10-20 NPK of Jack's Professional Peat-Lite Special) resulted in positive shoot growth but beyond 50 mg nitrogen/L reduced root mass. The 4-inch square pot was an effective container type. A survey of 30 Montana native plant growers indicated a demand for native plants in the Montana nursery industry. However, more work needs to be completed to develop and stabilize the native plant market.