Plant Pathology Commons^™

The Effects Of Residue Amounts And Variety Selection On The Development Of Wheat Fungal Pathogens In South Dakota, Abrielle Tembreull

Electronic Theses and Dissertations

Roughly 50% of South Dakota cropland is under the practice of no-till, with large increases in acres of no-till in the last 20 or so years. No-till is beneficial for Great Plains states, such as South Dakota, as soil residues are withheld. Residues are shown to increase soil health through retention of moisture and increase of microorganisms, but residues can serve as a source of inoculum for fungal pathogens that can overwinter on them. As wheat is one of the most important food crops in the world, it is important to protect this vital crop from diseases. Diseases of wheat …

Unveiling Race Diversity And Fungicide Sensitivity Profiles Of Pyrenophora Tritici Repentis Populations In South Dakota Collected From 2021-2023, Jaswinder Kaur

Electronic Theses and Dissertations

Tan spot, a foliar disease of wheat caused by the ascomycetes fungus Pyrenophora tritici repentis (Ptr), poses a significant threat to wheat crops globally. The disease gained economic importance in the late 1970s due to shifts in farming practices, such as minimal tillage and planting on crop residues, providing favorable conditions for the pathogen to overwinter and cause infections. Ptr is classified into eight races based on the production of necrotrophic effectors—Ptr ToxA (necrosis-inducing), Ptr ToxB, and Ptr ToxC (chlorosis-inducing on respective susceptible and sensitive cultivars)—resulting in distinct symptoms on susceptible wheat differentials. The inverse gene-for-gene hypothesis of Ptr suggests …

Fusarium Head Blight Resistance Assessment In Barley, Tasneem Fathima

Electronic Theses and Dissertations

Fusarium head blight (FHB), commonly called scab is the most devastating disease of wheat and barley caused by the ascomycete fungus, Fusarium graminearum. FHB affects both the quality and quantity of cereal grains affecting the supply chain of the food and feed industry and the marketability of the produce. Barley (Hordeum vulgare L.) is among the several crop species most vulnerable to FHB infection. An estimated 25% of Spring barley grain production in the United States is used to make malted beverages such as beer. Malting barley is a relatively high-value crop with high demands regarding grain quality. FHB directly …

The Role Of Map Kinases, Transcription Factors, Callose Binding Proteins In Systemic Acquired Resistance, Xinyu Yuan

Theses and Dissertations--Plant Pathology

Systemic acquired resistance (SAR) is a broad-spectrum disease resistance induced upon local infections that provides protection against secondary infections. Earlier work has shown that SAR is regulated by two parallel pathways, one of which is regulated by salicylic acid (SA), and the other one involves pipecolic acid (Pip), nitric oxide (NO), reactive oxygen species (ROS), azelaic acid (AzA), and glycerol-3-phosphate (G3P). Pip acts upstream of NO, ROS, AzA, and G3P in the local leaves but the distal accumulation of Pip depends on the biosynthesis and transport of SA and G3P.

Normal induction of SAR also requires mitogen-activated protein kinase (MPK) …

Exploring The Effects Of Environmental Factors On Rice Blast Disease, April Ellen Lamb

Theses and Dissertations--Plant Pathology

Rice blast disease, caused by the ascomycete fungus Magnaporthe oryzae, occurs in over 85 countries and results in an annual crop loss of 10-30%, a corresponding nutrient value of meals for 60 million people. As a result, it is listed as a critical plant disease by the United Nations. Understanding factors affecting disease severity is of critical concern for food security. M. oryzae has been used as a model system for studying effector-triggered immunity (ETI) by understanding that ETI is primarily a plant response. M. oryzae has been used as a model to study fungal pathogenicity, host specificity, genome …

Fungicide Sensitivity In P. Tritici-Repentis Diverse Population And Phenotyping Of Spelt Wheat For Multiple Diseases, Zunera Shabbir

Electronic Theses and Dissertations

Pyraclostrobin, a QoI fungicide, is extensively used in the management of fungal leaf spot diseases. In this study, 215 P. tritici-repentis isolates collected from wheat fields in South Dakota were evaluated for their sensitivity to Pyraclostrobin. Of 215 isolates, 48 isolates (22%) exhibited insensitivity based on G143A mutation and EC50 values using spore germination assay. Our results indicate reduced sensitivity to insensitivity to pyraclostrobin in some isolates suggesting regular monitoring of the P. tritici-repentis population to QoI fungicides is essential to track the evolution of insensitive population. Spelt wheat (Triticum spelta L.) is an ancient cereal that is gaining small …

Biological Control Of Bacterial Leaf Streak Of Wheat Using Antagonistic Rhizobacteria, Ashley Frederickson

Electronic Theses and Dissertations

Wheat (Triticum aestivum L.) is one of the world’s most valuable crops, and the primary food grain produced in the United States. A major disease in wheat production is Bacterial Leaf Streak (BLS) caused by the gram-negative bacterium Xanthomonas translucens pv. undulosa (Xtu). Very few management strategies are available to growers to manage this disease, as common chemicals do not provide adequate control. A number of studies have been conducted on biological control using Rhizospheric bacteria for the control of various plant diseases, but limited data is available on the efficacy of biological control using Rhizospheric bacteria for controlling Bacterial …

Opportunities And Challenges In Augmenting Honey Bee Forage Resources With Pasture Legumes In Southern Australia, M. Kratz, M. Brown, M. T. Newell, R. C. Hayes

IGC Proceedings (1977-2023)

More than 80% of Australian honey is produced from native tree and shrub species. However, with increasing demands on public lands along with production risks posed by drought, floods and wildfires, there is a need to identify alternative forage resources to augment Australian honey production. With over 30 pasture legumes now available for agriculture in southern Australia, opportunity exists to increase the utilisation of some species with co-benefits to multiple production industries. However, there is little understanding of the potential value of most pasture legumes for honey production, and side by side comparisons are complicated by factors such as differences …

Data Curation For Modeling Tall Fescue Biomass Dynamics With Dssat-Csm, M. B. Hanson, P. D. Alderman, T. J. Butler, A. Caldeira Rocateli

IGC Proceedings (1977-2023)

While models for predicting forage production are available to aid management decisions for some forage crops, there is limited research for a yield model designed specifically for tall fescue (Schedonorus arundinaceus). Therefore, our objective was to adapt an existing perennial forage model, the Decision Support System for Agrotechnology Transfer Cropping Systems Model (DSSAT-CSM) for predicting forage biomass of tall fescue in the southern Great Plains. To evaluate model performance, there must first be a high level of data manipulation and cleaning. In this project, a cohesive dataset combining biomass, weather, soil, and management data were structured into DSSAT …

Can Changing Breeding Structure Serve As A Climate Adaptation Strategy? Evidence From A Comparative Study Of China And Mongolia, Y. Zhang, Z. Huang, J. Wang, Y. Huang, T. Hao, G. Xu

IGC Proceedings (1977-2023)

Under the influence of climate change, the vulnerability of grassland ecosystems in the Mongolian Plateau has increased. Correspondingly, herdsmen need to adopt more livelihood adaptation strategies to cope with changes in climate and grassland environment. The purpose of this study is to analyze the impact of breeding structure on grassland quality in Mongolian plateau. We select 20 border provinces/banners of Mongolia and Inner Mongolia Autonomous Region for research, and combined statistical data with remote sensing data of 2007-2016. The Normalized Difference Vegetation Index (NDVI) is used to quantify the grassland vegetation quality. Results show that there are differences in livestock …

Natural Transmission Of Grapevine Vein Clearing Virus, Matthew Manu

Graduate Theses/Dissertations

More than 60 million tons of grapes are produced annually in the world, making them one of the most widely grown fruit crops. Despite grapes’ economic and health benefits, biotic stressors, such as viruses, cause significant loss to the grape and wine industry. One such virus is grapevine vein clearing virus (GVCV) which seriously threatens grape cultivation in the Midwest region of the United States. This virus has caused the removal of seven commercial vineyards since its discovery in 2004. About 34% of Ampelopsis cordata wild vines are infected with GVCV and serve as a primary inoculum for the spread …

Distribution Patterns Of Allorhizobium Vitis In Missouri Vineyards And Non-Vineyard Soils, Jacquelyn M. Wray

Graduate Theses/Dissertations

Crown gall disease causes significant economic loss to the grape and wine industry. Preventive strategies are most effective for mitigating the loss of grapevines in vineyards, as there is no known cure for this disease. The bacterium Allorhizobium vitis carrying a tumor-inducing (Ti) plasmid is the causative agent. A. vitis bacteria live systemically in the grapevine before causing visible symptoms and can survive in residual plant tissues and soil for more than two years. Diagnostic methods have been developed to detect A. vitis bacteria in grapevines and soil. However, more reliable, specific, and high-throughput diagnostics are still needed for screening …

Investigation Of Fungal Pathogens And Woodboring Beetles Of Sugarbush Stands In The Central Appalachian Region, Molly A. Sherlock

Graduate Theses, Dissertations, and Problem Reports (ETD)

The production of maple syrup is a valuable source of income and cultural identity for many rural communities throughout the central Appalachian region. Regardless, maple syrup producers face difficulties maintaining the health and productivity
of their stands due to various impacts of climate change, which have given rise to extreme weather events that exacerbate damage caused by pests and diseases. To ensure the long-term sustainability of the maple syrup industry, it is crucial to obtain a comprehensive understanding of the current biotic threats within the region, particularly woodboring insects and fungal pathogens. However, insufficient information exists regarding the community assemblages …

Screening Of Rice Genotypes Against Brown Spot Disease At Rampur, Chitwan, Nepal, Sanjok Timalsina

Graduate Student Scholarship

Brown spot of rice caused by Bipolaris oryzae (Breda de. Haan) Shoemaker is one of the major constraints of rice production in all rice growing regions of Nepal. To identify and select the sources of brown spot resistance in rice genotypes, a field experiment was conducted under the natural epiphytotic condition at National Maize Research Center, Rampur, Chitwan in 2022. A total of 10 genotypes, including susceptible check (Sabha Mansuli SUB-1) and resistant check (Sabitri) were tested. The field experiment was laid out in a randomized complete block design with three replications. Brown spot disease assessment was done based on …