Submitted to: European Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/13/2013
Publication Date: 4/12/2013
Citation: Babiker, E.M., Hulbert, S.H., Schroeder, K., Paulitz, T.C. 2013. Evaluation of Brassica species for resistance to Rhizoctonia solani and binucleate Rhizoctonia (Ceratobasidum spp.) under controlled environment conditions. European Journal of Plant Pathology. Volume 136, Issue 4, pp. 763-772. Interpretive Summary: The roots and stems of canola are attacked by a number of groups of Rhizoctonia in the Pacific Northwest. In this work, we screened a collection of canola varieties and genotypes for resistance or tolerance to four of these pathogen groups. No resistance was found for R. solani AG 2-1, them most aggressive pathogen. Three promising genotypes with moderate levels of resistance to R. solani AG 10, R. solani AG 8 and binucleate Rhizoctonia were identified.
Technical Abstract: Isolates of R. solani AG 2-1, AG 8, AG 10 and binucleate Rhizoctonia (Ceratobasidium spp.) were tested for virulence on Brassica crops in growth chamber experiments. Isolate virulence and genotype resistance were determined based on percent of seedling survival, shoot length, and shoot fresh weight. Isolates had significant effects on all tested measurements, compared to the non-inoculated controls. R. solani AG 2-1 appears to be the most aggressive pathogen on all tested genotypes followed by R. solani AG 8, binucleate Rhizoctonia and R. solani AG 10, respectively. Genotype by isolate interaction effects were found to be significant for percent of seedling survival and shoot length reduction in the both trials of the experiments. None of the tested genotypes exhibited any level of resistance or tolerance to R. solani AG 2-1, but three promising genotypes with moderate levels of resistance to R. solani AG 10, R. solani AG 8 and binucleate Rhizoctonia were identified. Seed age had significant effects on the percent of seedling emergence. Regardless of the genotype, old seeds were more susceptible to damping- off from R. solani AG 8 than newly harvested seeds. Moderate heritability (0.57) was observed for the percent of seedling survival in the resistant genotype KS4022.