Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/14/2000
Publication Date: 5/1/2001
Citation: Bradley, C.A., Hartman, G.L., Nelson, R.L., Mueller, D.S., Pedersen, W.L. 2001. Evaluation of ancestral soybean lines for resistance to rhizoctonia root and crown rot. ASA meetings, Minneapolis, MN, November 2000. Agronomy Abstracts. p. 96.
Technical Abstract: Rhizoctonia root and crown rot of soybean, caused by Rhizoctonia solani, can cause damping off or cause lesions on the hypocotyl or root. There have been few reports of cultivars with resistance to R. solani. Ninety ancestral soybean lines were evaluated for resistance to R. solani (root and crown rot) in the greenhouse. Soybeans were planted into trays containing a 2:1 ratio of sand and soil mix. Each tray contained a susceptible cultivar (Jack) and a resistant cultivar (Centennial or Savoy). Plants were inoculated at the hypocotyl regions with a mycelial suspension of R. solani (AG 2-2) at the VE growth stage and were rated for disease severity using a 0-5 scale after 14-21 days. Twenty-one of the lines had disease ratings equal (P < 0.05) to the resistant cultivar Centennial. Of these twenty-one lines, CNS (PI 341.246), Jackson (PI 548.657), and Mandarin Ottawa (PI 548.379) are in the background of cultivars previously reported as being resistant to Rhizoctonia root and crown rot.