PLP894 Seminar Spring 2026: Pranavasri Maddi (Linda Hanson Lab)
April 27, 2026 1:30PM - 2:30PM
Room A271
Seedling Diseases of Sugarbeet in Michigan.
Pranavasri Maddi, Linda E. Hanson, Tom R. Goodwill.
Abstract
Sugarbeet (Beta vulgaris subsp. vulgaris) production in Michigan is affected by seedling diseases that limit stand establishment and slow early growth. Sugarbeet damping-off has historically been largely caused by Aphanomyces cochlioides and Rhizoctonia solani, however, a recent survey and an ongoing survey of Michigan sugarbeet fields have been done from 2023 to the present shows some potential additional pathogens. Findings from this survey are consistent with a survey conducted in Michigan between 2008 and 2014. Fusarium species were isolated from symptomatic plants in over half of surveyed fields and was the sole pathogen isolated from some fields. This study aims to assess pathogens causing seedling disease. Because of finding Fusarium spp. as a consistently high level of pathogens in diseased seedlings, the work further aims to evaluate the pathogenicity of representative Fusarium spp. and isolates of the more common species. For the survey, symptomatic seedlings were collected based on agriculturalist observations. Potential pathogens were isolated and identified using morphological characteristics and molecular techniques. For pathogenicity screening, an initial 54 Fusarium isolates were selected to include the more commonly isolated species and some species that had not previously been reported to cause damage to sugarbeet seedlings. A subset of 13 representative isolates from eight different species was evaluated on two sugarbeet breeding lines (C869 and FC309) using colonized barley grain inoculum. These breeding lines were chosen for differences in resistance to Fusarium wilt in adult plants. Assays were conducted in greenhouse conditions with eight Fusarium species: F. acuminatum, F. avenaceum, F. circinatum, F. equiseti, F. graminearum, F. oxysporum F. proliferatum, and F. semitectum. All tested isolates caused significant seedling symptoms, such as yellowing, damping-off, chlorosis, and stunting. No significant differences were observed in disease response between breeding lines. These results confirm that diverse Fusarium species can contribute to seedling diseases in Michigan sugarbeet. This was the first report of seedling damage from three species. These results indicate that consideration of Fusarium species may be needed in seedling disease management. The survey and isolate screening will continue to better understand the composition and variability of the Fusarium species affecting sugarbeet in Michigan.
Print
Email