Search Results

Now showing 1 - 10 of 97
  • Item
    Genetics and Quantitative Trait Loci Mapping of Septoria Tritici Blotch Resistance, Agronomic, and Quality Traits in Wheat
    (North Dakota State University, 2013) Harilal, Vibin Eranezhath
    Most breeding programs aim at developing superior germplasm and better cultivars that combine high yield, disease and pest resistance, and end-use quality to satisfy the requirements of the growers as well as industry. A population, consisting of 138 F2-8 recombinant inbred lines (RILs) derived from a cross between ‘Steele-ND’ and ND 735, was evaluated to study the inheritance pattern of the septoria tritici blotch (STB)-resistant genes, agronomic and quality traits. The framework map made of 392 markers, including 28 simple sequence repeat (SSR) markers and 364 DArT markers, spanned a total distance of 1789.3 cM and consisted of 17 linkage groups. The map position of quantitative trait loci (QTL) found in this study coincided with the map position of durable STB resistance genes, Stb1. Thirteen QTL were detected for agronomic and quality traits. More saturation of the current map is needed to explore more QTL for this population.
  • Item
    Identification of Molecular Markers Linked to X-Disease Resistance in Chokecherry
    (North Dakota State University, 2012) Wang, Hongxia
    X-disease, caused by phytoplasmas, is one of the destructive diseases in stone fruit trees, causing yield loss and poor fruit quality. So far no effective methods are available to control X-disease. X-disease resistance has been first discovered in chokecherry (Prunus virginiana, 2n=4x=32), which is a native woody species of North America. To identify molecular markers linked to X-disease resistance, simple sequence repeat (SSR) markers were used to construct genetic linkage maps for chokecherry and to identify markers associated with X-disease resistance in chokecherry. In this research, three segregating populations of chokecherry were developed by crossing one X-disease resistant (CL) with three susceptible chokecherry lines (a, c, and d), of which the progenies were 101, 177, and 82, respectively. In order to construct a genetic map for chokecherry, 108 pairs of SSR primers were employed from other Prunus species. Additionally, a set of 246 SSRs were developed from chokecherry sequencing by Roche 454 sequencing technology. A total of 354 pairs of SSR primers were used to screen individuals of all three populations. Two software programs, TetraploidMap and JoinMap, were used to construct linkage map based on single-dose restriction fragments (SDRFs) and two parental linkage maps were generated for each population from both software programs. Bulked segregant analysis (BSA) was applied for identification of X-disease resistance markers. As a result, one SSR marker was found to be linked to the X-disease resistance. The set of 246 chokecherry SSRs was later used to test transferability among another 11 rosaceous species (sour cherry, sweet cherry, wild cherry, peach, apricot, plum, apple, crabapple, pear, june berry, and raspberry). As a result, chokecherry SSR primers can be transferable in Prunus species or other rosaceous species. An average of 63.2% and 58.7% of amplifiable chokecherry primers amplified DNA from cherry and other Prunus species, respectively, while 47.2% of amplifiable chokecherry primers can be transferable to other rosaceous species. The genetic information, including genetic map, disease linked marker, chokecherry sequence, and confirmed transferability of the identified chokecherry SSRs to other species, will benefit the genetic research in Prunus and other rosaceous species.
  • Item
    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.
  • Item
    Identification of Molecular Markers for Marker-Assisted Selection of Malting Quality and Associated Traits in Barley
    (North Dakota State University, 2015) Jung, Renata
    Barley (Hordeum vulgare L.) is one of the most important cereal crops in North Dakota, which ranks second amongst all states for barley production in the United States. Barley is used for the production of malt, which is used for brewing beer. The malting and brewing industries set strict standards for malt quality; yet, determining malt quality of experimental barley lines is very expensive. For this reason, quality is typically determined at the latter stages of the breeding program, resulting in rejection of many genotypes after large investments for agronomic performance, disease resistance, and end-use quality evaluations have occurred. High quality malt cultivars must possess numerous genetically controlled characteristics. This limits the effectiveness of phenotypic selection for malt quality. The use of marker-assisted selection (MAS) may enable breeders to eliminate lines with undesirable traits earlier in the breeding process, reducing costs, and improving genetic gain. In spite of the large number of mapped QTLs, few examples exist in the literature in which QTL analysis and MAS have been applied to the genetic improvement of malting barley. This research was initiated to identify robust marker-trait associations for malting quality, disease resistance, and agronomic traits utilizing genome-wide association mapping of selected NDSU two-rowed lines. Our research successfully identified numerous marker-trait associations for the traits evaluated to be used for MAS to improve the North Dakota State University barley breeding program.
  • Item
    Variation in Core and Accessory Parts of Genome of Escherichia Coli Isolated from Soil from Riparian Areas in New York State
    (North Dakota State University, 2016) Maistrenko, Oleksandr
    Escherichia coli is commensal bacteria and is a symbiont of the digestive system of vertebrates. Due to frequent deposition of E. coli into extrahost habitats (soil, water), approximately half of its population exists as free living organisms. It is unclear what genome-wide variation stands behind adaptation for extrahost habitat. This thesis applies a genome-wide association study approach to find genetic variation in core and accessory parts of genome of E. coli that is associated with 1) forest or agricultural field soil habitats and 2) with survival phenotype in soil microcosm. Gene composition analysis suggests that pan-genome of environmental E. coli is unlimited. Core and accessory genome contained variation associated with survival phenotype and with forest or field habitat.
  • Item
    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.
  • Item
    Frontenac' Response to Leaf Removal and Training Systems and a Microvinification and Deacidification Bioassay of Interspecific Hybrids (Vitis SPP.)
    (North Dakota State University, 2016) Olson, Brittany Korynta
    Vineyard production and acid reduction microvinification experiments were conducted on interspecific hybrid grape cultivars in North Dakota. Training system and leaf removal effects on yield and quality for ‘Frontenac’ were assessed. Training system treatments included Geneva Double Curtain, High Cordon, Vertical Shoot Positioned, and 4-Arm Kniffin, and leaf removal treatments applied at bloom, post-bloom, veraison, and no removal. It was found that yield gains due to training system may be reached without negatively affecting fruit quality. The deacidification ability of biological and chemical treatments were assessed on the wines of ‘Frontenac’, ‘La Crescent’, and ‘King of the North’. Biological treatments included Saccharomycetes cerevisiae (Maurivin B and 71B) and Oenococcus oeni (ER1A and EY2d), and the chemical deacification treatment cold stabilization. Greatest reduction of titratable acidity resulted from the combined biological and chemical treatments. This project and future research contributes to the optimization of grape growing and winemaking within our region.
  • Item
    Quantitative Genetic Analysis of 16 Maize Populations Adapted to the Northern U.S. Corn Belt
    (North Dakota State University, 2013) Laude, Tonette
    Genetic diversity is essential for genome sequencing and a key contributor to increase frequency of favorable alleles for maize improvement. The objectives of this study were to determine the genetic components, assess the genetic diversity, and propose the heterotic grouping of a large sample of short-season maize populations based on multiple traits. Sixteen maize populations were included in a diallel mating design that followed Gardner-Eberhart Analysis (GEAN) II to estimate variety (vi) and heterosis (hij) genetic effects. The general combining ability (gi) estimates were also determined and used to classify the populations based on their genetic diversity. Data were generated in partially balanced single lattice experiments across North Dakota (ND) locations in 2010, 2011, and 2012. Combined analyses of variance showed significant differences among genotypes. Heterosis effects explained the most among diallel entries sum of squares for grain yield, while vi effects had greater influence on grain quality traits. The gi effects agreed with the genetic effect that had larger contribution to the total among diallel entries sum of squares for various traits. Three groups were formed based on the genetic distances (GD) of the gi estimates. Four heterotic groups were established based on sij estimates for grain yield. Close correspondence was observed between the groups formed using GD and sij. The heterotic grouping among populations agreed with their genetic background information and heterotic group’s specific and general combining ability (HSGCA) estimates. The EARLYGEM 21 populations having exotic background were assigned to a unique heterotic group. The heterotic groups established among these populations will increase breeding efficiency to improve and develop genetically broad-based populations. Inter-population recurrent selection programs can be employed for population crosses with high grain yield and above average grain quality formed by parental populations belonging to different heterotic groups. Intra-population recurrent selection programs can also be established for the parental populations identified with desirable grain quality traits. These populations will serve as unique germplasm sources of short-season diverse inbred lines to produce the next generation of diverse northern U.S. hybrids. New heterotic patterns have been established as a source of new commercially viable single-cross and population hybrids. [Full abstract in document contains symbols]
  • Item
    Genetic Diversity and Genome-Wide Association Mapping of Agronomic, Disease Resistance, and Quality Traits in Barley Accessions from Ethiopia, Icarda, and the U.S.
    (North Dakota State University, 2015) Daba, Sintayehu Debebe
    Plant breeding is a dynamic process that incorporates new germplasm to introduce genetic variation. Knowledge gained from genetic diversity studies and identification of potentially useful germplasm is critical for efficiently utilizing these new materials for breeding program. Linkage disequilibrium (LD), diversity, and association mapping analyses in barley (Hordeum vulgare L.) were done using a mapping panel that included Ethiopian landraces, and cultivars and breeding lines from the Ethiopian, ICARDA, and NDSU breeding programs. LD decayed within 10 to 20 cM in the mapping panel and large proportions of unlinked loci were found to have large LD estimates, indicating that factors other than linkage contributed to LD. Diversity analyses using phenotypic data and molecular markers indicated that the mapping panel was highly structured according to spike row-type, geographic origin, and breeding history; thus, accounting for population structure and familial relatedness was crucial for association analyses. Comparison of the four models (Naïve, P, K, and P+K) indicated that the P+K model is the best model for the current mapping panel. The genome-wide association study (GWAS) identified 94 QTL for 14 agronomic and disease resistance traits; and 145 QTL for 11 malt and grain quality traits. Association mapping of agronomic and disease resistance traits identified six photoperiod related loci (Ppd_H1, HvFT4, HvGI, HvFT2, HvCO2, and HvCO1) and one vernalization-related locus (VRN-H1) for days to heading, one semi-dwarf locus (sdw3) for plant height, and four resistance loci (Rrs1, Rrs15, rpt.k and rpt.r). The largest number of QTL for malt and grain quality traits was detected in chromosome 5H, followed by chromosome 7H. QTL for malt and grain quality traits were mapped near the Hor1, Hor2, Upg2, Dor4, Ltp1, Amy1, and Amy2 loci. Several unique QTL were identified in the ICARDA and NDSU accessions, with the NDSU materials having the favorable marker genotypes. These regions could be useful to the Ethiopian breeding program for improving malt quality. The current study indicated that association mapping provided useful tool to identify QTL for several traits simultaneously. Because the QTL had small effect and distributed across the genome, genome selection may be warranted for improving these traits.
  • Item
    Improving Efficacy of Metribuzin and Rimsulfuron in Potato Production
    (North Dakota State University, 2016) Winchester, Adam Miller
    Rimsulfuron and metribuzin are postemergence herbicides used to control broadleaf weeds in potato and are applied with adjuvants to improve efficacy. Postemergence weed control often coincides with fungicide treatments. Therefore, studies were conducted to determine the effect of adjuvants or fungicides (chlorothalonil or mancozeb) plus metribuzin and rimsulfuron on weed control, potato safety and yield. Common sunflower and common lambsquarters visual control was ≥ 91% when metribuzin (420 and 210 g ha-1) plus rimsulfuron (26 and 14 g ha-1) combinations were applied with or without fungicides. Past the four leaf stage, metribuzin (340 g ha-1) and rimsulfuron (21 g ha-1) with adjuvants had no effect on hairy nightshade dry weight. Adjuvants and fungicides did not change yield. These studies indicate that including fungicides with metribuzin and rimsulfuron reduce weed populations without negatively impacting yield. Additional research is needed to determine the effect of adjuvants with these herbicides on other weeds.