Plant Pathology Commons^™

Insect Pest Management With Sex Pheromone Precursors From Engineered Oilseed Plants, Hong-Lei Wang, Bao-Jian Ding, Jian-Qing Dai, Tara J. Nazarenus, Rafael Borges, Agenor Mafra-Neto, Edgar B. Cahoon, Per Hofvander, Sten Stymne, Christer Löfstedt

Center for Plant Science Innovation: Faculty Publications

Pheromones have become an environmentally friendly alternative to conventional insecticides for pest control. Most current pheromone-based pest control products target lepidopteran pests of high-value crops, as today’s manufacturing processes cannot yet produce pheromones at low enough costs to enable their use for lower-value crops, especially commodity crops. Camelina sativa seeds genetically modified to express (Z)-11-hexadecenoic acid, a sex pheromone precursor of several moth species, provided the oil from which the precursor was isolated, purified and transformed into the final pheromone. Trap lures containing this pheromone were then assessed for their capacity to manage moth pests in the field. Plant-derived pheromone …

Helping Utah Landowners Reduce Pesticide Use Through A Statewide Ipm Program, Nick Volesky, Mair Murray

Outcomes and Impact Quarterly

The Utah Integrated Pest Management (IPM) program provides outreach and education to Utahns to reduce pesticide use and ultimately protect human and environmental health. In 2022, the IPM program responded to stakeholders’ needs by partnering with county Extension offices to deliver eight (8) in-person workshops across the state. The workshops connected Extension specialists and county faculty with managers of home landscapes and farms. The objective of the workshops was to provide participants with IPM skills to identify, monitor, and manage pest problems in preparation for the upcoming growing season.

Arkansas Corn And Grain Sorghum Research Studies 2021, Victor Ford, Jason Kelley, Nathan Mckinney Ii

Arkansas Agricultural Experiment Station Research Series

The 2021 edition of the Arkansas Corn and Grain Sorghum Research Studies Series includes research results on topics pertaining to corn and grain sorghum production, including weed, disease, and insect management; economics; sustainability; irrigation; post-harvest drying; soil fertility; mycotoxins; cover crop management; and research verification program results. Our objective is to capture and broadly distribute the results of research projects funded by the Arkansas Corn and Grain Sorghum Board. The intended audience includes producers and their advisors, current investigators, and future researchers. The Series serves as a citable archive of research results.

Increasing The Resilience Of Plant Immunity To A Warming Climate, Jong Hum Kim, Christian Castroverde, Shuai Huang, Chao Li, Richard Hilleary, Adam Seroka, Reza Sohrabi, Diana Medina-Yerena, Bethany Huot, Jie Wang, Sharon Marr, Mary Wildermuth, Tao Chen, John Macmicking, Sheng Yang He

Biology Faculty Publications

Extreme weather conditions associated with climate change affect many aspects of plant and animal life, including the response to infectious diseases. Production of salicylic acid (SA), a central plant defence hormone, is particularly vulnerable to suppression by short periods of hot weather above the normal plant growth temperature range via an unknown mechanism. Here we show that suppression of SA production in Arabidopsis thaliana at 28 °C is independent of PHYTOCHROME B (phyB) and EARLY FLOWERING 3 (ELF3), which regulate thermo-responsive plant growth and development. Instead, we found that formation of GUANYLATE BINDING PROTEIN-LIKE 3 (GBPL3) defence-activated biomolecular condensates (GDACs) …

Interdisciplinary Team Addresses Cotton Leafroll Dwarf Virus In Alabama, Kassie N. Conner, Edward Sikora, Jenny Koebernick, Marcio Zaccaron

Journal of Extension

A multi-state and interdisciplinary team was formed to address the Extension and research needs of CLRDV, an emerging cotton disease with high potential impact for U.S. cotton production. In 2017, CLRDV was identified in AL and Auburn University immediately formed an interdisciplinary working group composed of plant breeders, plant pathologists, entomologists, and agronomists. Since then, scientists from ten other states have joined the CLRDV group. Thus, allowing research to be coordinated efficiently and best deploy limited resources to attend the stakeholder’s needs. The CLRDV group produces and shares new and relevant information with the scientific community and cotton producers alike.

Michigan Conifer Growers’ Perspectives On Disease Management, Emily S. Huff, Monique L. Sakalidis

Journal of Extension

A survey of commercial nursery and Christmas tree growers was implemented online and by mail in 2018 to understand disease issues and information preferences. Overall, the majority of the respondents reported that they prefer online sources of information and many are using Extension bulletins and sources. Cultural, chemical, and weed control methods were considered extremely effective by participants and very few used biological control methods to control disease. Participants identified spruce decline, boxwood blight, and hemlock woolly adelgid as emerging disease threats, so future information to growers should focus on identification and management of these threats.

The Pho1;2a'-M1.1 Allele Of Phosphate1 Conditions Misregulation Of The Phosphorus Starvation Response In Maize (Zea Mays Ssp. Mays L.), Ana Laura Alonso-Nieves, M. Nancy Salazar-Vidal, J. Vladimir Torres-Rodríguez, Leonardo M. Pérez-Vázquez, Julio A. Massange-Sánchez, C. Stewart Gillmor, Ruairidh J. H. Sawers

Center for Plant Science Innovation: Faculty Publications

Plant PHO1 proteins play a central role in the translocation and sensing of inorganic phosphate. The maize (Zea mays ssp. mays) genome encodes two co-orthologs of the Arabidopsis PHO1 gene, designated ZmPho1;2a and ZmPho1;2b. Here, we report the characterization of the transposon footprint allele Zmpho1;2a'-m1.1, which we refer to hereafter as pho1;2a. The pho1;2a allele is a stable derivative formed by excision of an Activator transposable element from the ZmPho1;2a gene. The pho1;2a allele contains an 8-bp insertion at the point of transposon excision that disrupts the reading frame and is predicted to …

Divergent Evolution Of Extreme Production Of Variant Plant Monounsaturated Fatty Acids, Lu Gan, Kiyoul Park, Jin Chai, Evan M. Updike, Hyojin Kim, Adam Voshall, Sairam Behera, Xiao-Hong Yu, Yuanheng Cai, Chunyu Zhang, Mark A. Wilson, Jeffrey P. Mower, Etsuko Moriyama, Chi Zhang, Sireewan Kaewsuwan, Qun Liu, John Shanklin, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Metabolic extremes provide opportunities to understand enzymatic and metabolic plasticity and biotechnological tools for novel biomaterial production. We discovered that seed oils of many Thunbergia species contain up to 92% of the unusual monounsaturated petroselinic acid (18:1Δ6), one of the highest reported levels for a single fatty acid in plants. Supporting the biosynthetic origin of petroselinic acid, we identified a Δ6-stearoyl-acyl carrier protein (18:0-ACP) desaturase from Thunbergia laurifolia, closely related to a previously identified Δ6-palmitoyl-ACP desaturase that produces sapienic acid (16:1Δ6)- rich oils in Thunbergia alata seeds. Guided by a T. laurifolia desaturase crystal structure obtained in this study, …

Epistatic Interaction Between Rhg1‑A And Rhg2 In Pi 90763 Confers Resistance To Virulent Soybean Cyst Nematode Populations, Pawan Basnet, Clinton G. Meinhardt, Mariola Usovsky, Jason D. Gillman, Trupti Joshi, Qijian Song, Brian Diers, Melissa G. Mitchum, Andrew M. Scaboo

Biomedical Sciences

Key message

An epistatic interaction between SCN resistance loci rhg1-a and rhg2 in PI 90763 imparts resistance against virulent SCN populations which can be employed to diversify SCN resistance in soybean cultivars.

Abstract

With more than 95% of the $46.1B soybean market dominated by a single type of genetic resistance, breeding for soybean cyst nematode (SCN)-resistant soybean that can effectively combat the widespread increase in virulent SCN populations presents a significant challenge. Rhg genes (for Resistance to Heterodera glycines) play a key role in resistance to SCN; however, their deployment beyond the use of the rhg1-b allele has been …

Plectus Of The Prairie: A Case Study Of Taxonomic Resolution From A Nematode Biodiversity Survey, Abigail Borgmeier, Kaitlin Gattoni, Timothy Harris, Rebecca Higgins, Peter Mullin, Dorota Porazinska, Kirsten S. Powers, David A. Wedin, Tom Powers

Department of Plant Pathology: Faculty Publications

Taxonomic resolution is a critical component of biodiversity assessments. In this case study, we examined a single taxon within a larger study of nematode diversity to evaluate the taxonomic resolution of different diversity assessment methods. The selected taxon was the microbial-feeding genus Plectus, a group considered to include multiple cosmopolitan species. The methods included a morphological evaluation by light microscopy, Sanger sequencing of PCR amplicons of COI and 18S gene regions, and 18S metabarcoding sequencing. The study sites were 15 remnant tallgrass prairie plots in eastern Nebraska. In the morphological analysis, we observed two basic morphotypes, a short-tailed form …

Association Mapping Across A Multitude Of Traits Collected In Diverse Environments In Maize, Ravi V. Mural, Guangchao Sun, Marcin Grzybowski, Michael C. Tross, Hongyu Jin, Christine Smith, Linsey Newton, Carson M. Andorf, Margaret R. Woodhouse, Addie M. Thompson, Brandi Sigmon, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

Classical genetic studies have identified many cases of pleiotropy where mutations in individual genes alter many different phenotypes. Quantitative genetic studies of natural genetic variants frequently examine one or a few traits, limiting their potential to identify pleiotropic effects of natural genetic variants. Widely adopted community association panels have been employed by plant genetics communities to study the genetic basis of naturally occurring phenotypic variation in a wide range of traits. High-density genetic marker data—18M markers—from 2 partially overlapping maize association panels comprising 1,014 unique genotypes grown in field trials across at least 7 US states and scored for 162 …

Efficacy And Timing Of Application Of Fungicides, Biofungicides, Host-Plant Defense Inducers, And Fertilizer To Control Phytophthora Root Rot Of Flowering Dogwoods In Simulated Flooding Conditions In Container Production, Krishna Neupane, Bhawana Ghimire, Fulya Baysal-Gurel

Agricultural and Environmental Sciences Faculty Research

Phytophthora root rot caused by Phytophthora cinnamomi Rands is one of the major diseases of flowering dogwoods (Cornus florida L.). The severity of root rot disease increases when the plants are exposed to flooding conditions. A study was conducted to determine the efficacy and timing of application of different fungicides, biofungicides, host plant defense inducers, and fertilizer to manage Phytophthora root rot in month-old seedlings in simulated flooding events for 1-, 3-, and 7- days. Preventative treatments were drench applied 3 weeks and 1 week before flooding whereas curative treatments were applied 24 hrs. after flooding. Dogwood seedlings were inoculated …

Characterization Of Corynespora Cassiicola Resistance To The Quinone Outside Inhibitor Fungicides, Elucidation Of Fitness Parameters, And Defining Alternative Fungicide Product Strategies In Mississippi Soybean, Xiaopeng Wang

Theses and Dissertations

Target spot, caused by Corynespora cassiicola, is a common lower canopy disease of soybean in the southern United States. Given the recent resurgence of target spot and increasing reports of resistance to the quinone outside inhibitor (QoI) fungicide class within C. cassiicola, a survey of C. cassiicola from the Mississippi soybean production system was initiated in 2019 to determine the nature of its resistance mechanisms. A total of 819 monoconidial isolates were collected from 228 geographic field locations in 75 Mississippi counties. The molecular mechanism of resistance was determined using a PCR-RFLP analysis by comparing nucleotide sequences in …

Epidemiology And Impacts Of A Leaf Spot Disease In Veratrum Viride (Melanthiaceae), Leeah R. Sutton, Foster Levy

Undergraduate Honors Theses

Fungal phytopathogens can cause disease epidemics in crops, weeds, and
populations of native plants. To investigate the impact of a foliar phytopathogen on the native herbaceous species, Veratrum viride, a demographic and disease assessment was carried out on two high elevation grassy bald populations on Roan Mountain, Tennessee. A leaf spot disease impacted all plants in both populations, causing widespread premature senescence of leaves and stems. Disease severity increased over the course of the growing season. Based on host disease symptoms and fungal conidia morphology, Pseudocercosporella sublineolata was shown to be the causal pathogen. A study of herbarium specimens …

An In Vitro Approach To Identify Sources Of Resistance To Fusarium Wilt Caused By Fusarium Oxysporum F. Sp. Vasinfectum Race 4 In Domesticated Cotton, Stephen Parris

All Theses

Cotton lint produced by the plants Gossypium barbadense L. (pima cotton) and Gossypium hirsutum L. (upland cotton) is the world’s leading source of renewable textiles. The fibers of the cotton plant have been woven so intricately into our society that it would be hard to imagine life without their products. Cotton breeders must then not only continue to work to improve the quality of cotton fibers (fineness, strength, dyability, etc.) but also to improve the resilience of the plant against biotic and abiotic factors. Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4) is an aggressive fungal pathogen, which causes Fusarium …

Identification Of Cytospora Species Isolated From Canker In Peach Trees In South Carolina, Stephen T. Baker

All Theses

In 2016, a survey was conducted into the causes of twig blight on peach (Prunus persica) in five orchards across South Carolina. From this survey, isolates from the fungal genus of Cytospora (Sordariomycetes, Diaporthales) were reported on peach, for the first time, within the state. Cytospora species are known to cause oozing cankers on a wide range of woody hosts leading to dieback, loss of limbs, and reduction in yield, prompting concern for important economic crops. Past methods of identification of Cytospora species have been confounded by indistinguishable morphology, overlapping host preference among species, and genetic sequencing …

Functional Characterization Of A Putative Alternative Oxidase In Sporisorium Reilianum F. Sp. Zeae., Emma A Lamb

College of Arts & Sciences Senior Theses

Sporisorium reilianum is a pathogenic basidiomycete fungus with two formae speciales, each capable of infecting corn (SRZ) or sorghum (SRS), respectively. This fungus is also a dimorphic variety, meaning it can switch between its haploid, yeast-like sporidia and diploid teliospore stages over the course of its life cycle (Schirawski). When S. reilianum is found in a haploid state and conditions are favorable, it will mate with a compatible non-self mating type to begin filamentous growth and proliferation in the plant host (Zhao). S. relianum, like most fungi, utilizes the four classical components of the electron transport chain to produce …

A Small Stem Assay For Chestnut Blight Resistance In Hybrid American Chestnut Trees, Evelyn Odle

Honors Theses

Cryphonectria parasitica (Murr.) Barr is the causal agent for the chestnut blight disease, which was brought to North America in the late 19th century on nursery stock from Japan (Anagnostakis 1987). A pandemic of chestnut blight lasted for the next half century, nearly wiping out all American chestnut trees (Castanea dentata Borkh.). Restoration works to restoring the American chestnut to its native range in North America’s canopy has been going on for the past century. The American Chestnut Foundation has strived to breed a resistant American chestnut by backcross breeding with Chinese species (C. mollissima Blume) since the 1980s. The …

Site-Specific Pest Management In Nebraska Corn And Soybean Production Systems, Zachary D. Rystrom

Doctor of Plant Health Program: Dissertations and Student Research

Site-specific management (SSM) is widely used by farm producers to fertilize their fields. However, whole field management is currently practiced in integrated pest management (IPM). Site-specific management and agricultural technology can improve IPM especially when precision application of inputs can reduce selection pressure on pest populations, benefit the environment, or save costs of inputs. There is potential for site-specific pest management (SSPM) where pests, or environments vary spatially, and recommended management practices can be applied with precision. Three case studies are evaluated for SSPM to be applied in Nebraska corn and soybean production systems including corn rootworm, preemergence herbicides, and …

Distribution And Genomic Diversity Of Pollen-Borne Viruses And Viroids At The Interface Of Peach And Wild Prunus Spp. In The Southeastern United States, Fabian Omar Rodriguez Bonilla

All Theses

Prunus necrotic ringspot virus (PNRSV), prune dwarf virus (PDV), and peach latent mosaic viroid (PLMVd) are important pollen-borne pathogens that affect peach orchards in the southeastern United States. My aim with this research is to identify potential sources of virus/viroid inoculum sources in the wild and determine pathogen movement and interactions between wild Prunus spp. and cultivars of peach (P. persica). In Chapter I, I review the literature on pollen borne viruses and viroids in peach. In Chapter II, I surveyed for these pathogens near peach production areas in South Carolina and Georgia, sampling from three endemic wild …