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Crosscutting Understandings Of Fusarium Resistance In Sorghum And Wheat For Development Of Breeding Strategies And Novel Opportunities In Germplasm Improvement, Arlyn Ackerman

All Dissertations

Fusarium causes widespread disease in crops resulting in yield and quality loss across a range of host taxa that results in global incidence of carcinogenic mycotoxins contaminating the world’s food systems. This research sought to crosscut frameworks developed across the Fusarium host crop species of wheat (Triticum aesitivum) and sorghum (Sorghum bicolor [L] Moench) to further understand mycotoxin suppression and resistance. A deeper understanding of the biochemical resistances available in sorghum grain mold (SGM) was built by following research of wheat based upon deoxynivalenol resistance to Fusarium head blight (FHB). Through this research, phenotyping methods for Fusarium damaged kernels …

Genetic Control Of Prickles And Plant Height In Blackberry, Carmen Johns

Graduate Theses and Dissertations

The fresh-market blackberry (Rubus L. subgenus Rubus Watson) industry has been expanding for the past two decades. Blackberry market growth can be attributed to many factors including expanded production regions, improved production systems, and release of superior cultivars. Blackberry breeding is a time- and labor-intensive process which would benefit from implementation of molecular markers for highly heritable, important traits. Next generation sequencing, a high-quality reference genome, and software capable of analyzing this complex genome were applied in a genome-wide association study (GWAS) to reveal maker-trait associations related to prickles and plant height variation in fresh-market blackberry. In 2020 and 2021, …

Multi-Year Data Analysis And Genomic Selection To Improve The Efficiency Of A Rice Breeding Program, Tommaso Cerioli

LSU Doctoral Dissertations

Plant breeding dramatically improved crops performances during human history and will play a pivotal role in shaping the future of agriculture. However, this activity requires large amount of time and resources. The availability of multi-year datasets and abundant DNA information enables new analyses and breeding approaches that can increase the productivity and efficiency of a breeding program. In recent years, the LSU Rice Breeding Program has implemented marker assisted selection (MAS) and genomic selection (GS) to predict performance of rice genotypes before field testing. The goal of this project was to conduct analyses and test molecular approaches to increase the …

Qtl Mapping Of Panicle Architecture And Yield-Related Traits Between Two U.S. Rice Cultivars 'Lagrue' And 'Lemont', Adam D. Rice

Graduate Theses and Dissertations

Grain yield in rice consists of multiple yield components such as number of panicles/plant, number of tillers/plant, and number of seeds/panicle. Panicle architecture is an important yield trait yield as the number of seeds on a panicle greatly contributes to the overall panicle yield. A QTL analysis and mapping study on panicle architecture and yield-related traits was performed to identify major QTL and candidate genes associated with the traits. The first objective of the project was to do a yield study evaluating 15 agronomic traits between each of the four U.S. rice cultivars, ‘LaGrue’, ‘Lemont’, ‘Bengal’, and ‘Mars’, to determine …

Genetic Resistance To The Downy Mildew Pathogen And Mapping The Rpf Resistance Loci In Spinach, Gehendra Bhattarai

Graduate Theses and Dissertations

Spinach (Spinacia oleracea) is an important cool-season leafy vegetable crop in the United States (US). Downy mildew, caused by the obligate oomycete Peronospora effusa, is the most economically important disease of spinach. A total of 17 races of P. effusa have been reported on spinach, and many of these races (>10) have emerged in the last three decades. The new races of the pathogen are continually overcoming the genetic resistances used in the newly released cultivars.

A detached leaf inoculation assay was evaluated, standardized, and validated as a new method to differentiate resistant and susceptible spinach genotypes. Disease response …

Linkage Mapping For Soybean (Glycine Max) Flood Tolerance, Wade Stiles Hummer

Graduate Theses and Dissertations

Flood tolerance in soybean (Glycine max) is not a well-characterized trait, yet flooding damage is second only to drought stress in terms of yield reduction. The objectives of this study were to determine genetic variation for flooding tolerance in two populations of soybean recombinant inbred lines (RILs) and to identify and confirm flood tolerant QTL. Population A (WHA) consisted of 111 RILs derived from the cross 5002T by 91210-350 and Population B (WHB) consisted of 79 RILs from the cross RA-452 by Osage. Experiments were conducted at the Rice Research and Extension Center (RREC) near Stuttgart, AR in 2015 and …

Foraging Quality And Performance Of Yearlings Grazing Switchgrass Strains Selected For Differing Digestibility, Bruce Anderson, J. K. Ward, K. P. Vogel, M. G. Ward, Francis A. Haskins, Herman J. Gorz

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum) is a native, perennial warm-season grass commonly used as summer pasture. Three strains of switchgrass with different in vitro DM disappearance (IVDMD) values were evaluated with yearling cattle (Bos taurus) in three replicated grazing trials. All strains were similar in genetic background, maturity and yield potential. 'Trailblazer' (high-IVDMD) resulted in higher (P < .05) ADG than 'Pathfinder' and 'low-IVDMD'. Available forage of Trailblazer had higher IVDMD than Pathfinder and low-IVDMD. The IVDMD differences among strains were similar throughout the season; IVDMD declined between 0.3 and 0.5 percentage units per day. Forage availability, CP, NDF and ADF, permanganate lignin and ash were similar among strains. This study documents that plant breeders can select switchgrass plants for higher IVDMD and that strains consisting of progeny of these plants can result in higher animal gains than strains consisting of progeny of unselected or low-IVDMD plants with similar genetic background, forage yield, maturity, morphology and chemical composition.

Forage Quality And Performance Of Yearlings Grazing Switchgrass Strains Selected For Differing Digestibility, Bruce Anderson, J. K. Ward, K. P. Vogel, M. G. Ward, Herman J. Gorz, Francis A. Haskins

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum) is a native, perennial warm-season grass commonly used as summer pasture. Three strains of switchgrass with different in vitro DM disappearance (IVDMD) values were evaluated with yearling cattle (Bos taurus) in three replicated grazing trials All strains were similar in genetic background, maturity and yield potential. 'Trailblazer' (high-IVDMD) resulted in higher (P < .05) ADG than 'Pathfinder' and 'low-IVDMD'. Available forage of Trailblazer had higher IVDMD than Pathfinder and low-IVDMD. The IVDMD differences among strains were similar throughout the season; IVDMD declined between .3 and .5 percentage units per day. Forage availability, CP, NDF and ADF, permanganate lignin and ash were similar among strains. This study documents that plant breeders can select switchgrass plants for higher IVDMD and that strains consisting of progeny of these plants can result in higher animal gains than strains consisting of progeny of unselected or low-IVDMD plants with similar genetic background, forage yield, maturity, morphology and chemical composition.