Location: Sugarbeet Research
Title: Evaluation of sugar beet breeding lines for resistance to Rhizoctonia crown and root rot, 2023Author
LIEN, AUSTIN - University Of Minnesota | |
Chu, Chenggen | |
CHANDA, ASHOK - University Of Minnesota |
Submitted to: Plant Disease Management Reports
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/9/2024 Publication Date: 3/12/2024 Citation: Lien, A., Chu, C.N., Chanda, A. 2024. Evaluation of sugar beet breeding lines for resistance to Rhizoctonia crown and root rot, 2023. Plant Disease Management Reports. Page:18. Article V002. Interpretive Summary: Rhizoctonia crown and root rot (RCRR) is a serious fungal disease of sugar beet. Utilizing RCRR-resistant varieties is the most effective way for managing this disease. According to evaluations conducted in the 2022 growing season, several breeding lines from the USDA-ARS Sugar Beet Genetics program at Fargo, ND showed resistance or moderate resistance to RCRR. These lines were evaluated again in 2023 in a RRCR field nursery at the University of Minnesota, Crookston, MN. These lines showed similar resistance to that observed during previous growing season, demonstrating that their resistance is stable and will be very useful for sugar beet RCRR breeding programs around the world. Technical Abstract: Rhizoctonia crown and root rot (RCRR) is a serious fungal root disease for sugar beet caused by Rhizoctonia solani. According to RCRR resistance evaluation conducted in the last grown season, ten sugar beet breeding lines that showed RCRR resistance or moderately resistance were evaluated in this year in field nurseries at University of Minnesota, Crookston, MN with three replications included. Ground barley infested with Rhizoctonia solani isolate AG 2-2 was spread directly over sugar beet crowns at a rate of 20 g per row for inoculation. Roots were arbitrarily selected from each replication and rated for the severity of RCRR using a 0 to 10 scale with a 10% incremental increase per each unit of rating. A mixed-model analysis of variance was performed with breeding lines defined as the fixed factor and replication as the random factor. RCRR severity was statistically similar among all tested breeding lines, except for the line 20N0085, which was significantly greater than the resistant check C803. Numerically, three breeding lines (20N0140, 20N0154, and 20N0157) had the lowest RCRR incidence and can be used as genetic source to improve RCRR resistance. |