About

Gary N. Odvody is an Associate Professor in the Department of Plant Pathology & Microbiology at Texas A&M University. His educational background includes a B.S. in Botany from the University of Nebraska, obtained in 1969, followed by an M.S. and Ph.D. in Plant Pathology from the same institution, completed in 1973 and 1977 respectively. His research focuses on diseases of cereal crops caused by fungi, bacteria, and viruses, with a primary emphasis on fungal diseases affecting maize and sorghum. Key diseases studied include charcoal rot, sorghum downy mildew, head smut, aflatoxin contamination, sorghum ergot, and grain mold, among others. Odvody's work involves understanding pathogen ecology, survival, initial inoculum, pathogen variability, and host-parasite interactions, especially under stress environments. He is part of a large interdisciplinary sorghum improvement team at Texas A&M that is active globally through INTSORMIL research activities. Additionally, he is a member of Texas A&M AgriLife Extension Service, Texas A&M AgriLife Research, and other related organizations, contributing to research and extension efforts in plant pathology.

Research topics

• Agronomy
• Biology
• Ecology
• Horticulture
• Botany
• Medicine
• Genetics

Selected publications

• Genetic and Pathogenic Variability among Isolates of Sporisorium reilianum Causing Sorghum Head Smut

  Journal of Fungi · 2024-01-12 · 4 citations

  articleOpen access

  (L.) Moench) head smut, is present in most sorghum-producing regions. This seed replacement fungal disease can reduce yield by up to 80% in severely infected fields. Management of this disease can be challenging due to the appearance of different pathotypes within the pathogenic population. In this research, the genetic variability and pathogenicity of isolates collected from five Texas Counties was conducted. Due to the lack of available space, 21 out of 32 sequenced isolates were selected and evaluated for virulence patterns on the six sorghum differentials, Tx7078, BTx635, SC170-6-17 (TAM2571), SA281 (Early Hegari), Tx414, and BTx643. The results reveal the occurrence of a new pathotype, 1A, and four previously documented US pathotypes when the 21 isolates were evaluated for virulence patterns on the differentials. The most prevalent was pathotype 5, which was recovered from Brazos, Hidalgo, Nueces, and Willacy Counties, Texas. This pathotype was followed by 1A and 6 in frequency of recovery. Pathotype 4 was identified only from isolates collected from Hidalgo County, while pathotype 1 was from Burleson County, Texas. It appeared that the previous US head smut pathotypes (2 and 3) are no longer common, and the new pathotypes, 1A, 5, and 6, are now predominant. The phylogenetic tree constructed from the single-nucleotide polymorphism (SNP) data through the neighbor-joining method showed high genetic diversity among the tested isolates. Some of the diverse clades among the tested isolates were independent of their sampled locations. Notably, HS37, HS49, and HS65 formed a clade and were classified as 1A in the virulence study, while HS 61 and HS 66, which were collected from Nueces County, were grouped and identified as pathotype 5.

  PublisherOA PDFDOI

• Identification of naturally occurring atoxigenic strains of Fusarium verticillioides and their potential as biocontrol agents of mycotoxins and ear rot pathogens of maize

  Crop Protection · 2023-02-08 · 12 citations

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  PublisherDOI

• Registration of Tx3440 through Tx3482 sorghum germplasm

  Journal of Plant Registrations · 2021 · 9 citations

  • Biology
  • Agronomy
  • Horticulture

  Abstract The sorghum [ Sorghum bicolor (L.) Moench] germplasm lines Tx3440–Tx3482 (Reg. no. GP‐900–GP‐942, PI 695271–PI 695313) were developed and released by Texas A&M AgriLife Research, Lubbock, TX, in 2020. Breeding crosses from these lines were made in Lubbock, TX, with grow‐out and selection of subsequent generations completed in breeding nurseries throughout Texas over a period of years. Once selected, these lines were test for agronomic performance in replicated trials across multiple locations and years. Within the set, Tx3340–Tx3482 represent diverse pedigrees and an array of combinations of grain color, plant color, and other agronomic traits. The lines are individually resistant to selected abiotic (pre‐ and/or post‐flowering drought) stress and biotic stress (grain weathering caused by diverse genera that include Fusarium spp., Curvularia spp., and Alternaria spp.; and anthracnose caused by Colletotrichum sublineola ). These lines provide the sorghum industry with sources of drought tolerance, grain weathering, and anthracnose resistance in a diverse array of elite genetic backgrounds for use as seed parent lines for hybrid production and for new line development.

  PublisherDOI

• The response of sorghum cultivars to mixtures of compatible and incompatible isolates and different conidia concentrations of Colletotrichum sublineola

  Physiological and Molecular Plant Pathology · 2021-07-23 · 2 citations

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  PublisherDOI

• Genome‐wide association analysis for response of Senegalese sorghum accessions to Texas isolates of anthracnose

  The Plant Genome · 2021 · 22 citations

  • Biology
  • Genetics
  • Botany

  Anthracnose disease of sorghum is caused by Colletotrichum sublineola, a filamentous fungus. The genetic basis of resistance to anthracnose in sorghum is largely unclear, especially in Senegalese sorghum germplasm. In this study, 163 Senegalese sorghum accessions were evaluated for response to C. sublineola, and a genome-wide association study (GWAS) was performed to identify genetic variation associated with response to C. sublineola using 193,727 single nucleotide polymorphisms (SNPs) throughout the genome. Germplasm diversity analysis showed low genetic diversity and slow linkage disequilibrium (LD) decay among the Senegalese accessions. Phenotypic analysis resulted in relatively low differences to C. sublineola among the tested population. Genome-wide association study did not identify any significant association based on a strict threshold for the number of SNPs available. However, individual analysis of the top eight SNPs associated with relative susceptibility and resistance identified candidate genes that have been shown to play important roles in plant stress tolerance in previous studies. This study identifies sorghum genes whose annotated properties have known roles in host defense and thus identify them as candidates for use in breeding for resistance to anthracnose.

  PublisherOA PDFDOI

• Author Correction: Leaf angle distribution in Johnsongrass, leaf thickness in sorghum and Johnsongrass, and association with response to Colletotrichum sublineola

  Scientific Reports · 2021-05-07

  articleOpen access

  An amendment to this paper has been published and can be accessed via a link at the top of the paper.

  PublisherOA PDFDOI

• Leaf angle distribution in Johnsongrass, leaf thickness in sorghum and Johnsongrass, and association with response to Colletotrichum sublineola

  Scientific Reports · 2020-12-18 · 9 citations

  articleOpen access

  Basal leaf angle distribution was surveyed in twenty-one Johnsongrass cultivars near the end of the vegetative stage. The angles increased from the top to the bottom leaves, and compared to cultivated grain sorghums, the average angle was larger in Johnsongrass. When basal leaf angle distribution data were correlated with pathogenicity test data from excised-leaf assays for three isolates of Colletotrichum sublineola, the results showed a weak positive correlation between basal leaf angle and pathogenicity level in Johnsongrass. In order to investigate a protective role of leaf thickness to C. sublineola, leaf thickness was measured in three sorghum cultivars and one Johnsongrass cultivar at the 8-leaf-stage. Leaf thickness near the apex, near the base, and half-way between the two points were measured in the top four leaves of each plant. Thickness of leaf blade and midrib were recorded separately. Using an excised-leaf-assay, the three points were inoculated with C. sublineola, and pathogenicity level was recorded 4-days-post-inoculation. Results showed strong negative correlations between leaf midrib thickness and pathogenicity level in sorghum and Johnsongrass but not in leaf blades.

  PublisherOA PDFDOI

• Late Growth Stages of Johnsongrass Can Act as an Alternate Host of <i>Colletotrichum sublineola</i>

  Plant Health Progress · 2020 · 10 citations

  • Biology
  • Botany
  • Agronomy

  Twenty-six johnsongrass cultivars, collected from seven U.S. states, were spray inoculated with spores of an isolate of Colletotrichum sublineola derived from sorghum. Inoculations were made when plants reached growth stages of 2 (four to five leaves), 3 (seven to eight leaves), and 6 (post panicle emergence). At the earlier stages the johnsongrass cultivars showed hypersensitive responses and small lesions; however, acervulus formation was not observed. When late growth stage johnsongrass plants were spray inoculated, acervulus formation was confirmed in 19 cultivars as early as 5 days postinoculation. Results obtained confirm that johnsongrass can act as an alternate host of C. sublineola under favorable conditions, and growth stages of johnsongrass may be an important factor for cross infection of C. sublineola between johnsongrass and sorghum.

  PublisherOA PDFDOI

• Genome wide association analysis of sorghum mini core lines regarding anthracnose, downy mildew, and head smut

  PLoS ONE · 2019-05-14 · 46 citations

  articleOpen access

  In previous studies, a sorghum mini core collection was scored over several years for response to Colletotrichum sublineola, Peronosclerospora sorghi, and Sporisorium reilianum, the causal agents of the disease anthracnose, downy mildew, and head smut, respectively. The screening results were combined with over 290,000 Single nucleotide polymorphic (SNP) loci from an updated version of a publicly available genotype by sequencing (GBS) dataset available for the mini core collection. GAPIT (Genome Association and Prediction Integrated Tool) R package was used to identify chromosomal locations that differ in disease response. When the top scoring SNPs were mapped to the most recent version of the published sorghum genome, in each case, a nearby and most often the closest annotated gene has precedence for a role in host defense.

  PublisherOA PDFDOI

• Mating type a locus alleles and genomic polymorphism in Sporisorium reilianum: comparison of sorghum isolates to those from maize

  Australasian Plant Pathology · 2019-01-02 · 2 citations

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  PublisherDOI

Frequent coauthors

• Clint Magill

  Texas A&M University

  23 shared

• Louis K. Prom

  Southern Plains Agricultural Research Center

  22 shared

• William L. Rooney

  17 shared

• Debra E. Frederickson

  University of Edinburgh

  16 shared

• Thomas Isakeit

  Texas A&M University

  14 shared

• Noé Montes-García

  Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias

  14 shared

• Ezekiel Ahn

  Beltsville Agricultural Research Center

  11 shared

• D. T. Rosenow

  8 shared

Education

• B.S., Botany

  University of Nebraska

  1969

• M.S., Plant Pathology

  University of Nebraska

  1973

• Ph.D., Plant Pathology

  University of Nebraska

  1977