Plant Sciences Doctoral Work

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Adaptation of Quality Protein Maize (Zea Mays L.) to Northern U.S. Corn Belt
(North Dakota State University, 2015) Dong, Naiyuan
There is a need to increase the value of crops and develop the next generation of healthier products. Quality protein maize (Zea mays L.) is an option but has never been adapted to short – season environments. Quality protein maize (QPM) with homozygous embryo and endosperm for mutant allele o2 at the α-zeins regulatory gene opaque-2 shows about 60 to 100% increase in lysine and tryptophan essential amino acids when comparing with non-QPM maize. The objectives of this research were to adapt QPM genotypes to the northern U.S. through the NDSU Early QPM Program, and to evaluate the agronomic potential of early generation QPM lines and hybrids developed by the NDSU maize breeding program for the northern USA. Fifty-four inbred lines, including 47 QPM donor lines from the Iowa State University (ISU) maize breeding program, six experimental lines from the NDSU maize breeding program and one ex-PVP line from industry, were selected to produce 94 early-QPM backcross populations. Based on the earliness, protein content, and amino acid levels of lysine, 218 BC1S2 lines were selected for testcrosses with industry testers. Experiments evaluating testcrosses were arranged in 12 x 12 and 10 x 10 partially balanced lattice designs across three environments in 2013 and 2014. Based on this evaluation, totally 48 S2 lines were selected for further development, 17 of them representing the Stiff Stalk (SS) heterotic group and 31 representing the non-SS-group. Selected lines provided unique advanced inbred lines with hybrid combinations showing not only above average grain yield, dry down, and protein content but also, high levels of lysine, tryptophan, and methionine. The results of this research show, for the first time, the successful adaptation of QPM genotypes to short-season environments. The NDSU maize-breeding program has developed the first high quality maize products through the EarlyQPM and EarlyQPMF (for feedstock) national programs.
Advanced Cropping Systems for Oil and Biomass Feedstock Production in the Northern Great Plains
(North Dakota State University, 2015) Zayas, Alfredo Aponte
Video summarizing a Ph.D. dissertation for a non-specialist audience.
Agronomic Practices that Impact Grain Quality Factors of Durum Wheat (Triticum Turgidum L. Var. Durum Desf.)
(North Dakota State University, 2016) Forster, Shana M.
Durum wheat is a type of wheat primarily used for pasta production. North Dakota is the leading producer of durum wheat in the US with average yields of 2700 kg ha-1. Durum wheat price discounts are common and occur due to disease, heavy metal contamination, and environmental issues that impact grain quality. Studies were conducted in order to determine how agronomic approaches might impact durum quality. Experiments were conducted in order to determine what impact planting date, cultivar, and seeding rate had on the agronomic performance and quality of end-use traits. In general, a delay in planting date resulted in a significant decrease in yield and test weight for all cultivars. Cultivars differed for many of the end-use traits evaluated such as protein content, falling number, and vitreous kernel. Seeding rate had little impact on the traits evaluated. No combination of planting date and cultivar was identified that consistently resulted in grain marketed as US Grade 1 hard amber durum (HAD), or ‘choice durum’. Cultivar selection remains the best option for maintaining end-use traits. The effect of Zn fertilizer source and placement on grain Cd were evaluated. Treatments evaluated had no negative impact on grain yield or test weight. The foliar application of 1.1 kg Zn ha-1 Zn-EDTA in combination with 33 kg N ha-1 in the form of UAN applied at Feekes 10 growth stage (boot stage) resulted in the lowest grain Cd, and highest grain Zn, Fe and protein and represents an approach of biofortification for durum wheat.
Agronomic Studies of Forage Brassicas as Full-Season and Cover Crops for Grazing in North Dakota
(North Dakota State University, 2017) Teuber Winkler, Osvaldo Roberto
Annual forages represent a good feed resource to extend the grazing season into fall and winter, providing a good quality forage for the livestock, allowing more efficient use of rangeland, and at the same time improving soil properties. Many species in the Brassicaceae family are used as forages for grazing. Forage brassicas are characterized by high forage yield, with high nutritive value, low establishment and harvest cost (direct grazing), while providing many ecosystems services. Forage brassicas can be grown as full season forage crops or as cover crops planted after a grain crop. The objectives of this study were: 1) to identify brassicas species and cultivars with high biomass production and forage quality when grown as full-season and as cover crops in North Dakota; 2) to determine their optimum sowing date, plant density and the response to different N and S fertilization rates. Replicated experiments were conducted at four sites Fargo, Prosper, Carrington and Walcott, ND in 2012-2014. Results indicate swede (Brassica napus L. var. napobrassica) and kale [B.oleraceae L. convar. acephala (DC)] were the highest forage yielding brassicas when established in full-season and turnip [Brassica rapa L. var. rapa (L.) Thell).], cv. ‘Appin’ was the highest yielding sown after August. In full-season brassicas, delaying sowing date reduced total forage yield in all species but did not influence forage quality. In brassicas sown after August, total forage yield decreased significantly only in radish in the second sowing date. Plant density did not have an effect on forage yield or N accumulation averaged across environments and species in full-season forage brassicas. This was different in brassicas sown after August, where the highest forage yield was obtained with the highest plant density (≥200 plants m-2). Kale and swede leaf, root/stem, and dead matter yield increased up to 200 kg N ha-1 in a linear response. Sulfur and the interaction between N and S did not have an effect in forage yield and quality. Both full-season and cover crops forage brassicas have great potential as supplemental high quality forage for grazing in North Dakota.
Allelic Relationship of A. strigosa Crown Rust Resistance Factors and their Relationship to Pc38 Suppression
(North Dakota State University, 2018) Ardayfio, Naa Korkoi
An investigation of the suppression effect of Pc38 on Pc94 was conducted by developing F2 segregating populations from genotypes possessing Pc38 and Pc94, together with a population void of the Pc38. Segregating phenotypic ratios were used to determine the crown rust resistance suppression at the Pc38 locus. A Leggett/Df-38 F2 population, possessing no Pc38 gene, produced resistant to susceptible ratios of 3:1 and 2:1. Leggett/Dumont and Leggett/Steele population possessing a copy of Pc38 each, produced resistant to susceptible ratios of 1:3, 1:2 and 3:13. Leggett was the resistant parent possessing Pc94 while Dumont and Steele were the susceptible parents possessing Pc38. Df-38, a susceptible parent, contained neither Pc94 nor Pc38. CR91 was used to identify resistant and susceptible plants in the segregating populations. A factor closely linked to Pc38 or the gene itself was confirmed to suppress the resistance effect of Pc94 in this study. A second experiment was conducted to determine the allelic relationship of crown rust resistance genes in 08BT26-2, 08BT70-1, BT1020-1-1 and BT1021-1-1. The genotypes possessed resistance genes introgressed from A. strigosa similar to Leggett. Leggett is homozygous for Pc94. Four different F2 segregating populations were developed from Leggett by 08BT26-2, 08BT70-1, BT1020-1-1 and BT1021-1-1. A crown rust race virulent to Pc94 was used to determine resistant to susceptible ratios of the populations. Crown rust race 16MN (100- 3) was used to discriminate between resistant and susceptible plants. The allelism test confirmed that the resistance gene present in 08BT26-2 and 08BT70-1 genotypes were the same as Pc94 in Leggett while genotypes BT1020-1-1 and BT1021-1-1 were different.
Altering Grapevine Crop-load and Canopy Architecture Through Cultural and Genetic Methods
(North Dakota State University, 2020) Svyantek, Andrej William
North Dakota's extremely short growing season leads to premature harvest of unripe, high acid grapes with atypical fruit chemistry. To combat the short growing season, grape growers utilize labor intensive grapevine canopy management practices to expose grape clusters to sunshine for enhanced ripening potential. This research examined leaf removal and shoot-thinning, two widely utilized canopy management practices, for their effect on fruit chemistry of two regionally important, cold-hardy grapevines, ‘Frontenac’ and ‘Marquette’. These management techniques were effective at altering fruit chemistry as measured by sugar; however, they are costly to employ commercially due to yield reduction and labor requirements. Furthermore, they rarely impacted the targeted fruit component, acidity of grape must. Ultimately, we sought to mitigate labor expenses associated with on-farm canopy management practices by breeding cold-hardy grapevines with reduced single leaf area. To accomplish this goal, we utilized a novel mutant grapevine with highly dissected, technically compound leaves, ‘Chasselas Cioutat’. After crossing ‘Chasselas Cioutat’ with native, North Dakota isolated, wild riverbank grapes (V. riparia) and two interspecific breeding parents (‘Frontenac gris’ and ‘E.S. 5-8-17’), we observed developmental transitions within leaf shape of young seedling grapevines. Newly emerged leaves became progressively more lobed between main veins as seedlings exited juvenility. However, the targeted compound leaf form was not observed in outcrossed progeny, with one rare exception. For these reasons, grapevines were maintained under greenhouse conditions and advanced to the next generation. Within the first generation of inbreeding, segregation was observed for the distinct compound leaf trait. On-going work to isolate quantitative trait loci is merging genetic maps from multiple sequencing technologies with image analysis to create the first high-resolution understanding of genetic control of compound leaf shape in grapevines. Overall, these efforts have provided the foundation for future breeding aimed at incorporating functional leaf shapes (compound leaf morphology) in the vineyard. Future work in North Dakota grapevine management may need to focus on techniques that promote winter survival and early ripening. Future breeding efforts should continue to focus on the use of novel germplasm material to overcome biotic stresses, improve fruit quality, and increase environmental resistance.
Analysis and Identification of QTL for Resistance to Sclerotinia Sclerotiorum in Pea (Pisum sativum L.)
(North Dakota State University, 2018) Ashtari Mahini, Rahil
White mold caused by Sclerotinia sclerotiorumi s one of the most devastating diseases infecting field pea (Pisum sativum L.) which causes severe yield loss worldwide. Population 17 (Lifter/ PI240515), and Population 19 (PI169603/ Medora) were developed by single seed descent and screened by greenhouse evaluation and detached stem assay to identify potential sources of white mold resistance. Twenty-two partial resistant inbred lines were identified with short internode which met at least two resistance criteria based on lesion expansion inhibition (LEI) and nodal transmission inhibition (NTI). To find SNPs (single nucleotide polymorphism) responsible for white mold resistance, Populations 17 and 19 were genotyped using GBS (genotyping by sequencing) methodology and analyzed with the GBS-SNP-CROP pipeline. Linkage maps were constructed for each population and a composite map based on shared SNPs between the two populations was also generated. Nineteen QTL were identified as contributing to resistance to white mold. Seventeen were associated with LEI and two were associated with NTI. The QTL responsible for lesion expansion on LG VII were duplicated in the short internode subset of both populations. Partially resistant inbred lines and QTL responsible for white mold resistance identified in this study can be useful as resources for resistance to S. sclerotiorum in further experiments aimed at developing resistant cultivars.
Association Mapping and Genetic Diversity Studies of Agronomic and Quality Traits in Durum Wheat [Triticum turgidum L. var. durum (Desf.)]
(North Dakota State University, 2017) Johnson, Marina
Genetic diversity studies in breeding programs are important to identify parental lines for hybridization and introgression of desirable alleles into elite germplasm. The genetic diversity analysis of 283 North Dakota State University (NDSU) advanced durum wheat breeding lines developed during the last 20 years indicated that the population was structured according to its breeding history. Total genetic diversity analysis (HT = 0.334) showed adequate level of genetic variation. The results will help in breeding efforts to broaden the genetic base and select lines for crossing as well as for genetic and genomic studies to facilitate the combination of desirable alleles. The quantitative nature of important target traits, combined with environmental effects, makes it difficult to bring the desirable improvement in durum wheat to meet the expectations of all the stakeholders involved in the durum wheat industry. With an objective to identify molecular markers for marker-assisted breeding (MAB), the present study attempted to identify marker-trait associations for six agronomic and 29 quality traits using a genome-wide association study (GWAS) mapping approach. The study used two types of phenotypic datasets, a historic unbalanced dataset belonging to a total of 80 environments collected over a period of 16 years and a balanced dataset collected from two environments, to identify the applicability of historic unbalanced phenotypic data for GWAS analysis. A total of 292 QTL were identified for agronomic and quality traits, with 10 QTL showing major effects (R2 >15%). Over 45% of QTL for agronomic and quality traits were present in both the unbalanced and balanced datasets, with about 50% of those present in both environments in the balanced dataset. Genome-wide association mapping studies identified several candidate markers for use in marker-assisted selection (MAS) for height, gluten strength, distribution of small kernels, polyphenol oxidase (PPO) activity, and yield.
Characterization of Common Wheat Translocations Carrying Leaf Rust Resistance Genes from Alien Species
(North Dakota State University, 2016) Ibrahim, Mohamed Somo
Leaf rust caused by Puccinia triticina Erikss may inflict significant yield losses in wheat; however, can be controlled by breeding for increased host resistance. In earlier studies, effective, resistance has been transferred to common wheat from the wild relatives Thinopyrum ponticum (Lr19), Aegilops sharonensis (Lr56), Ae. peregrina (Lr59), and Ae. neglecta (Lr62). Each translocation was subsequently re-engineered by the induction of homoeologous chromosome exchanges with a normal wheat chromosome to remove unneeded alien chromatin. For each gene the 3-8 most promising recombinants that retained the least linkage drag, but could not be differentiated, were identified. This study employed physical and genetic mapping in conjunction with molecular markers and genomic in situ hybridization to identify those recombinants that are best suited for breeding. For each gene, the recombinant with the least alien chromatin that also appeared to be fully compensating was identified and marker loci suitable for marker-assisted selection were suggested.
Characterization of Surfactant Quality and Validation of Standard Water Conditioning Testing
(North Dakota State University, 2018) Adams, Jason Wayland
Adjuvants are products added to pesticide applications to increase pest control. There are many different types of adjuvants designed to solve certain problems. Surfactants are a major class of agricultural adjuvant used to increase the efficacy of pesticides. Many companies use physical and chemical characteristics to market surfactants. However, producers do not understand these characteristics. Field efficacy data should be used to effectively market surfactants, but is somewhat limited. The objective of the first study was to evaluate if chemical and physical characteristics of agricultural surfactants can be used to predict field performance. Chemical and physical characteristics tested included HLB, dynamic surface tension, contact angle, and absorption through isolated cuticles. When individual characteristics were used as covariates with field efficacy data, no consistent results were observed. Therefore, physical and chemical characteristics cannot be used to accurately predict field performance of surfactants. In 2011, Zollinger et al. published a paper titled “A test method for evaluating water conditioning adjuvants” as a standardized test method. While this has been an effective test method, a comparison of salt type used has never been conducted. The objective of this research was to validate the standardized test method using three artificially mixed hard water samples with calcium chloride, calcium formate, and calcium nitrate. Field trials were conducted near Hillsboro, ND in 2016 and 2017. Glyphosate and mesotrione were applied at 342 and 70 g ai ha-1, respectively. Three types of water conditioners were evaluated with glyphosate: diammonium sulfate (AMS), AMS replacement, and monocarbamide dihydrogen sulfate (AMADS). Herbicide antagonism was similar between the simulated hard water samples. Within each type of water conditioning adjuvant, antagonism was overcome similarly in all water types. The results of these studies validate the test method established by Zollinger et al. (2011).
Cloning and Characterization of the Iron-Regulated Transporter (IRT) Genes and Their Transcription Factors in Populus
(North Dakota State University, 2015) Huang, Danqiong
Iron deficiency causes chlorosis in many plant species, resulting in yield loss and poor quality. Many tree species including poplar are susceptible to iron deficiency. Trees suffering from iron deficiency often show interveinal chlorotic leaves and in severe cases, branches or an entire tree may die. In this study, two trees of Populus tremula L.‘Erecta’ growing near each other but with contrasting leaf color phenotypes were used to study the causes of chlorosis and the mechanisms of tolerance or susceptibility to iron chlorosis in poplar. A leaf analysis revealed that the iron deficiency tolerant tree (PtG) had a higher level of dry matter content, chlorophyll (a+b), Chl a/b ratio, Zn and Fe content than the iron chlorosis susceptible tree (PtY). A hydroponic culture confirmed the differences in aforementioned physiological parameters between PtG and PtY responding to iron deficiency. Two iron-regulated transporter genes (PtIRT1 and PtIRT3), the native promoter of the PtIRT1 gene (PtIRT1-pro), and two basic helix-loop-helix (bHLH) transcription factors (PtFIT and PtIRO) were cloned and characterized for their responses to iron deficiency in PtG and PtY. Deduced amino acid analysis revealed that PtIRT1, PtIRT3, PtFIT, and PtIRO in PtG were identical to those in PtY. Phylogenetic and putative domain analyses showed that PtIRT1, PtFIT, and PtIRO may function in iron homeostasis, while PtIRT3 may play a role in zinc transport in poplar. The expression of PtIRT1 and PtFIT are root-specific and up-regulated by iron deficiency. The expression of a GUS gene derived by PtIRT1-pro in tobacco was also up-regulated by iron deficiency, but was not root-specific. The expression of PtIRT3 is ubiquitous and up-regulated by iron deficiency, but significantly down-regulated by zinc deficiency. A high correlation in the expression between PtFIT and PtIRT1 was observed in PtG, but not in PtY. Transgenic poplars overexpressing PtIRT1 or PtIRT3 did not have enhanced Fe accumulation; however, an enhanced tolerance to iron deficiency was found in transgenic plants overexpressing PtFIT. The results suggested that the transcription factor PtFIT may be involved in iron deficiency response through regulation of PtIRT1 and PtFIT itself may be regulated by other factors in poplar.
Delineating Root System Architecture in Rapeseed/Canola (Brassica napus L.) through Molecular and Transcriptomic Approaches
(North Dakota State University, 2018) Arif Uz Zaman, Muhammad
Root system architecture of plant plays a key role in water and nutrient uptake from the soil, provides anchorage and acts as a storage organ. In this current research, we have focused on the molecular and physiological basis of root system variation in canola (Brassica napus L.). Genome wide association mappings in a diverse canola germplasm panel with ~37,500 and ~30,200 single nucleotide polymorphism (SNP) markers were conducted under greenhouse and field conditions, respectively. A total of 52 significant SNP markers associated with different root architectural traits were identified in the greenhouse study. Majority of the markers were distributed on five chromosomes, A01, A02, A04, C03 and C06, of B. napus. Twenty-two candidate genes related to root growth and development were detected within 50 kbp upstream and downstream of the significant markers. Three of these candidate genes, P-glycoprotein 6 (PGP6), Tetraspanin 7 (TET7) and ARABIDILLO-2, were co-localized with three markers on chromosome C03, A01 and A04, respectively. In the field study, 31 significant SNP markers associated with different root traits were detected. A total of 15 root related candidate genes were identified within 100 kbp upstream and downstream of different significant markers. We also analyzed and compared the transcriptomes from the root systems of spring (weak root system) and winter (vigorous root system) growth habits at two different time points, 30 and 60 days. A total of 169,646 transcripts were analyzed, of which, 582 and 555 transcripts were found to be significantly differentially expressed between spring and winter types at 30 and 60 days, respectively. Several cytokinin and gibberellin associated genes and genes sets were found to be upregulated in spring type compared to winter type at 60 days. Cytokinin has proven inhibitory effect on root system architecture in different crops, whereas, gibberellin promote root elongation but inhibit lateral root growth. Therefore, we suggest that cytokinin and gibberellin may play an important role in root system variation between spring and winter growth habits. Significant marker loci, candidate genes and transcriptome profile identified in this research will assist future research to understand the root system variation in rapeseed/canola.
Determining Optimum Seeding Rates for Diverse Hard Red Spring Wheat (Triticum Aestivum L.) Cultivars
(North Dakota State University, 2016) Mehring, Grant Harry
Seeding rate for maximum grain yield can differ for diverse hard red spring wheat (HRSW) (Triticum aestivum L.) cultivars and can be derived from a seeding rate response curve. Six groups of HRSW cultivars with combinations of Rht-B, Rht-D, and Ppd-D with two cultivars per group were planted in 2013-2015 at five seeding rates in 23 trials throughout Minnesota (MN) and eastern North Dakota (ND), USA. Seeding rates ranged from 1.59 – 5.55 million seeds ha-1. Planting dates represented optimum and delayed seeding dates. Agronomic measurements for plant height, lodging, stems per plant, protein, and yield were obtained. Stand loss measurements, defined as the amount of viable seeds that did not become established plants, ranged from 11-19% across seeding rates most commonly planted in the region. There was a seeding rate by cultivar interaction for plant height, protein, lodging, stems plant-1, and yield. As seeding rate increased stems per plant consistently decreased and there were large differences in tillering capacity between cultivars. Increased seeding rate caused increased lodging for those cultivars with a capacity to lodge. Seeding rate for maximum yield of the cultivars differed. Combined over all cultivars, the seeding rate for maximum yield increased as the average yield of an environment decreased. An analysis of covariance (ANCOVA) predictive model was built for yield and tillering. The model for yield across all environments was not predictive with a validation R2 of 0.01. However, when only the bottom six yielding environments out of the total 21 environments were used to build a yield model the predictions were more accurate with a validation R2 of 0.44. The model built and validated for tillering was predictive for the validation environments with an R2 of 0.71 for validation environments. Seeding rate trials continue to be useful for producers making seeding rate decisions for a range of agronomic reasons. Additionally, using regression predictions and separate training and validation datasets to predict yield and tillering with HRSW, genetic and geographic predictors show promise for recommending seeding rates for future environments.
Developing a DNA Fingerprint for Midwest Six-rowed Malting Barley
(North Dakota State University, 2012) Lewis, Magan Friskop
The requirements for brewing beer from barley (Hordeum vulgare L.) malt are specific and unique for each brewer. Anheuser-Busch InBev and Miller Coors Brewing Company (MillerCoors) are two major brewers in the United States that target different malt quality profiles for six-rowed barley malt. Two closely related cultivars developed by the University of Minnesota, Robust and Stander, differ greatly in agronomic and malt quality performance. Robust malt fits the requirements of MillerCoors and Stander malt has many of the parameters desired by Anheuser-Busch InBev. The close relationship between these two cultivars increases the chance of recognizing chromosome regions with the genes controlling malt quality traits. A total of 53 doubled-haploid (DH) lines (original population) and the parents from the Robust x Stander cross were grown at eleven locations in North Dakota and one location in Idaho the past six years. An additional 138 Robust x Stander DH lines were generated in 2009 and were evaluated alongside the original DH population in the summer of 2011 at two North Dakota locations. Agronomic data were collected at all locations and cleaned grain samples of the original population from six of the locations were micro-malted at NDSU. Three linkage maps were developed using the original and 191 DH line (entire) populations. The first linkage map was constructed using the original DH population, along with a total of 102 SNP, SSR, and DArT markers. The second and third linkage maps were developed using only 67 SNP markers, with the original and entire Robust x Stander DH population, respectively. The first map was used to identify QTL controlling malt quality and wort carbohydrate traits on chromosomes 4H, 5H, and 6H. The SNP map constructed using the original DH population was used to identify QTL controlling agronomic traits on chromosome 6H. The third map was used to identify QTL controlling agronomic traits on chromosomes 4H and 6H. The ultimate goal for this research in years to come is to develop a genetic haplotype that helps distinguish six-rowed barley lines suitable for MillerCoors and Anheuser-Busch InBev.
Development and Characterization of Wheat Germplasm for Resistance to Stem Rust UG99 in Wheat
(North Dakota State University, 2013) Zhang, Qijun
World wheat production is currently threated by stem rust (caused by Puccinia graminis f. sp. tritici) Ug99 race (TTKSK). The ongoing global effort to combat Ug99 is focusing on the identification and deployment of Ug99-resistant genes (Sr) into commercial cultivars. The objectives of this study were to identify TTKSK-effective Sr genes in untapped durum and common wheat germplasm and introgression of TTKSK-effective Sr genes from tetraploid wheat (Triticum turgidium) and Aegilops tauschii into hexaploids through production of synthetic hexaploid wheat (SHW). For identification of TTKSK-effective Sr genes, 177 durum and common wheat cultivars and lines were first evaluated using three highly virulent races TTKSK, TRTTF, and TTTTF and 71 cultivars and lines with TTKSK resistance were identified. The TTKSK-resistant cultivars and lines were then evaluated using six local races and the molecular markers that are diagnostic or tightly linked to the known TTKSK-effective Sr genes. The race specification and marker analysis showed that several previously deployed TTKSK-effective Sr genes such as Sr2, Sr24 and Sr42 were present in some of the cultivars and lines. A number of resistant cultivars and lines derived from wheat relatives such as Thinopyrum ponticum, Th. elongatum, Th. intermedium, and Ae. speltoides may carry novel Sr genes. For SHW development, 200 new SHW lines were developed by crossing 181 tetraploid wheat accessions to 14 Ae. tauschii accessions. Sixty-six of the new SHW lines, 14 previously-developed SHW lines, and their parents were evaluated for resistance to TTKSK, TRTTF, TTTTF and six other races and genotyped using molecular markers linked to the known genes in T. dicoccum and Ae. tauschii. The evaluation data showed that 44 SHW lines were resistant to TTKSK. The race specification and marker analysis showed that Sr2 from T. dicoccum and Sr33 from Ae. tauschii were present in some of the SHW lines and a number of SHW lines have novel genes conferring TTKSK resistance. The durum and wheat cultivars and lines and SHW lines with known and novel Sr genes conferring resistance to TTKSK will be useful resources for improving wheat resistance to TTKSK and other emerging races of stem rust.
Dual Role of Phenolic Bioactives in Improving Functional Health Benefits and Abiotic Stress Resilience in Barley
(North Dakota State University, 2021) Ramakrishna, Ramnarain
Food insecurity, climate change, and public health challenges are interconnected and pressing issues facing humanity in the 21st century. Therefore, it is imperative to address key obstacles underlying food and nutritional insecurity by developing strategies to concurrently improve the nutritional benefits and environmental stress resilience of food crops. The metabolic and physiological roles of plant-derived phenolic compounds are particularly relevant in addressing these challenges. Phenolic compounds are an integral part of plant adaptive defense responses against biotic and abiotic stresses. When consumed as part of diet, certain phenolic compounds from plant-based foods also provide wider protection against metabolic breakdowns and related health risks associated with non-communicable chronic diseases (NCDs). Therefore, the central theme of this dissertation is to delineate the dual protective roles of phenolic compounds in improving crop stress resilience and their human health protective functions, specifically antioxidant and anti-hyperglycemic benefits supporting management of early stages of type 2 diabetes. Barley was used as a model crop; initially several malting barley samples were screened based on their phenolic-linked antioxidant and anti-hyperglycemic functions using in vitro assay models. Following metabolically driven screening, novel bioprocessed elicitor treatments such as marine protein hydrolysates and chitosan oligosaccharides were used as seed and foliar treatments to improve type 2 diabetes supporting dietary functions through upregulation of proline-associated pentose phosphate pathway (PAPPP), which is linked to the biosynthesis of phenolic metabolites. Improvement of phenolic biosynthesis and type 2 diabetes related benefits were observed in grains and sprouts with targeted elicitor treatments. Further, elicitor treatments were also found to positively improve PAPPP-linked metabolic responses under abiotic stresses, such as high soil salinity and water logging stress. From a human health perspective, food barley tea and coffee were found to have significant phenolic-linked antioxidant, and anti-hyperglycemic benefits. Additionally, integrated bioprocessing strategy by combining sprouting with mixed Kefir culture-mediated fermentation was found to improve phenolic-linked antioxidant, anti-hyperglycemic, and human gut health benefits relevant functionalities in pigmented and unpigmented food barley substrates. Therefore, these metabolically driven strategies can be targeted to screen both abiotic stress resilience and human health protective functions in malting and food barley varieties.
Early-Season Weed Control in Direct-Seeded Onion (Allium Cepa L.)
(North Dakota State University, 2012) Loken, James Ryan
Onion is a poor competitor with early-season broadleaf weeds. In addition, there are no current herbicide labels that allow POST application prior to the onion two-leaf stage in ND and PRE herbicide options provide inconsistent results. Bromoxynil and oxyfluorfen at reduced rates plus adjuvants were evaluated in the greenhouse for common lambsquarters and redroot pigweed control and crop safety when applied to onion prior to the two-leaf stage. Bromoxynil and oxyfluorfen plus methylated seed oil (MSO) or petroleum oil concentrate (POC) had the greatest onion safety compared to other tested adjuvants and provided acceptable weed control 12 d after three sequential applications. 14C-oxyfluorfen absorption was evaluated in the laboratory 24 h after treatment and oxyfluorfen absorption was greatest at 35 C compared to 15 and 25 C. Multiple applications of bromoxynil and oxyfluorfen at reduced rates were further evaluated with MSO or POC in field experiments. Bromoxynil provided 12% better common lambsquarters control and 9 t/ha greater large-grade onion yield than oxyfluorfen. Greater reduced rates resulted in greater common lambsquarters control and reduced common lambsquarters stand density. Common lambsquarters control was 24 to 32% greater when POC or MSO were used, respectively, compared to no adjuvant. Bromoxynil did not reduce onion stand/m as rates increased, but oxyfluorfen reduced onion stand as rates increased. Four or five sequential bromoxynil or oxyfluorfen applications every 7 d resulted in 14 to 19% greater weed control than three sequential applications. Onion stand was severely reduced by PRE herbicide and multiple reduced-rate application combinations.
Environmental Influence on Cold-Climate Grapevine (Vitis Spp.) Fall Acclimation Response and Fruit Ripening
(North Dakota State University, 2016) Stenger, John
Two experiments were conducted to determine differences in sensitivity to temperature among cold-climate grapevine genotypes in fall-acclimation response. One experiment utilized a growth chamber to compare grapevine plantlets under reducing photoperiod in two static temperatures through the quantification of seven predictor variables. Reduction models were compared for their effectiveness in interpreting the interaction among cultivars, traits, photoperiodic times, and temperatures. All models identified three similar axes relating the genotypes. Tucker decomposition was better able to separate wild genotypes from hybrids, was more consistent in the subspace defined, and was more readily interpretable, thus was preferred over SVD. Adapted types, V. riparia and ‘Frontenac’, showed increased tip responsiveness to temperature while V. riparia and ‘MN 1131’ more temperature response in their relative active growth to tissue maturation compared with marginal types including ‘Marquette’. Overall, it seems at least one strategy for temperature adaptive response is required in addition to early onset of acclimation for successful adaptation to the Northern Plains Region. In a second study, mature plants of three locally important cultivars were evaluated under five environmental conditions for similar acclimation traits along with fruit maturation traits under naturally decreasing photoperiod and temperature regimes. Reductions of phenotypic and temperature trends lead to a correlation between axes contrasting investigated years. Unique responses to temperature reduction were found in all cultivars, while ‘Marquette’ was additionally more responsive under temperature increases as it reverted to an active growth state. These alterations were speculated to be caused by differential partitioning of phloem resources within the plant through control of stomatal conductance. Lastly, a unique genotype was discovered. The genotype was determinate in both growth and reproduction in contrast to the indeterminate vining growth habit that defines members of Vitis. The natural mutant may have use in research on plant reproductive and vegetative growth regulation. Overall, insight was gained into the contrasts among acclimation processes within Vitis hybrids, and the use of growth chamber based evaluations of V. riparia derived progeny for background selection may lead to more rapid introgression of adaptive traits into favorable quality backgrounds in cold-climate Vitis breeding.
Genetic Analysis of Frost Tolerance in Rapeseed/Canola (Brassica Napus L.)
(North Dakota State University, 2017) Fiebelkorn Wrucke, Danielle
Frost can be detrimental to canola (Brassica napus L.) production. Depending on the severity, the entire field can be killed. Having frost tolerance in canola would benefit growers by allowing them to plant early, utilize early season moisture, and avoid high heat during flowering. However, frost tolerance in canola has not been well studied. A protocol was developed that determined 14 day old seedlings should be acclimated at 4°C for 7 days before being exposed to overnight frost (-4°C) in a small freezing chamber. However, when a larger chamber was used for freezing, the protocol was optimized to -8°C instead. A greenhouse study was conducted on a diverse collection of 231 genotypes and genome-wide association scan (GWAS) was conducted to identify potential genes that were related to frost tolerance or abiotic stress tolerance. Thirty-eight significant single nucleotide polymorphism (SNP) markers were selected based on 10,000 bootstraps and 0.1 percent tail of the empirical distribution. The markers were located on chromosomes A01, A02, A03, A04, A07, A08, A09, A10, C03, C05, C06, C07, and C09. Stepwise regression highlighted a QTL located on chromosomes A02. Another GWAS was done on 147 canola germplasm lines phenotyped under natural conditions. Thirty-eight significant SNPs identified from this study were located on chromosomes A05, A07, A09, C01, C02, C03, C04, C05, C06, C07, and C09. Stepwise regression identified a QTL located on chromosome C04. A protocol was developed to measure the freezing induced electrolyte leakage from leaves of rapeseed/canola. A total of 157 germplasm lines were evaluated for freezing induced (-12°C for 2 h) electrolyte leakage. Thirty-six significant SNPs located on chromosomes A01, A02, A03, A04, A05, A06, A07, A08, A09, A10, C01, C02, C04, C05, C06, C07, and C09 were identified. Stepwise regression identified 10 QTL located on chromosomes A01, A02, A04, A06, A07, C02, C05, C07, C09, and one that could not be assigned. All GWAS studies identified potential genes of interest that were related to frost tolerance, abiotic stress, and transcription factors.
Genetic and Physiological Relationships between Oat Grain Quality Components
(North Dakota State University, 2013) Dorcinvil, Ronald
The use of oats for human consumption is increasing every day due to the health benefits of oat products. With the objective to study relationships among factors affecting oat grain quality, two Recombinant Inbred Lines (RIL) mapping populations (`ND030299' x `ND991151' and `ND030299' x `Souris') have been used in this study. The two populations with their parents and three check cultivars were evaluated in a square lattice design in 2008 and 2009 at two North Dakota locations. Data were recorded on the following agronomic traits: grain yield, test weight, 1000 kernel weight, thin kernels, heading date, and plant height. Chemical and grain physical analysis were performed for â-glucan, oil, and groat percentage. A total of 4975 SNP markers were assessed on the two populations using a 32-bead chip platform developed by Illumina. QTLs for agronomic and grain physical traits were mapped and characterized in the two populations using Windows QTL Cartographer. Grain yield was positively correlated with test weight, thin kernels, plant height, â-glucan content, and associated negatively with 1000 kernel weight. Thirty linkage groups using 1168 polymorphic markers were formed for population 05021, whereas population 05026 comprised 33 linkage groups using 1024 polymorphic markers. The 30 linkage groups of population 05021 contained from 3 to 62 markers, and varied in size from 15.8 to 225.3 cM for a total map size of 2601.7 cM. The 33 linkage groups of population 05026 comprised from 2 to 42 markers, and varied in size from 2.3 to 143.2 cM for a total map size of 1174.2 cM. Nineteen genomic regions on 14 linkage groups were significantly associated with agronomic and grain chemical traits in the population 05021. Fourteen genomic regions on 12 linkage groups were identified for agronomic traits in the population 05026. The same genomic region on LG 05021-16 was associated with thin kernels, test weight, 1000 kernel weight, and oil content. LG 05026-19 loci, from position 23.7 to 47 cM, had strong effects on heading date, plant height, and grain yield. The QTLs consistently detected across environments and between the two populations could serve as starting points for marker-assisted selection.

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