Announcement of Final Thesis Defense Plant Pathology Ph.D. Degree: candidate Qiurong Fan
July 17, 2026 1:00PM - 2:00PM
A Combined Approach to Managing SoybeanTaproot Decline, caused by Xylaria necrophora
Date: July 17, 2026
Time: 1:00 pm EST in PSSB A271
Members of the Examining Committee and their Department:
- Dr. Alejandro Rojas - Plant, Soil and Microbial Sciences
- Dr. Martin I. Chilvers - Plant, Soil and Microbial Sciences
- Dr. Addie Thompson - Plant, Soil and Microbial Sciences
- Dr. Rich Adams – Entomology and Plant Pathology, University of Arkansas
ABSTRACT
Soybean taproot decline (TRD), caused by Xylarianecrophora, is an emerging root disease of increasing concern in soybean production. Disease symptoms may range from seedling death and root deterioration to foliar chlorosis, necrosis, and reduced yield later in the season. However, knowledge of its diagnosis, pathogen detection, host interactions, field dynamics, and genome resources remains limited. This research integrates diagnostic, controlled environment assay, field, and genomic approaches to advance understanding of TRD. First, a diagnostic guide and a TaqMan quantitative PCR assay were developed to support identification and detection of X. necrophora in soybean roots and soil. The assay was applied to field samples toexamine pathogen distribution and to support disease assessments. Controlled environment experiments then evaluated the susceptibility of common cover crop species, showing that all evaluated species could be affected by the pathogen, although cereal crops generally showed less severe responses than legumes and brassicas. A multi-year field study further examined how cereal rye and pathogen inoculation influenced soybean stand establishment, disease expression, canopy development, root pathogen density, and grain yield. Inoculation was consistently associated with reduced stand establishment and yield, while cereal rye responses varied among years, cultivars, and disease conditions. Finally, high-quality genome assemblies were generated for multiple X. necrophora isolates, providing resources for future studies of pathogen diversity and biology. Together, this work provides foundational diagnostic, epidemiological, and genomic tools that may help advance future research and management strategies for soybean taproot decline.
Print
Email