Location: Sugarbeet and Bean ResearchTitle: Screening a dry bean Andean diversity panel for potential sources of resistance to Rhizoctonia root rot and damping-off
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 6/10/2015
Publication Date: 1/1/2016
Citation: Minier, D., Hanson, L.E., Cichy, K.A. 2016. Screening a dry bean Andean diversity panel for potential sources of resistance to Rhizoctonia root rot and damping-off. Phytopathology. 106:S1.6.
Technical Abstract: Rhizoctonia root rot and damping-off, caused by Rhizoctonia solani, are among the most economically important root and hypocotyl diseases in the world and affect a wide range of hosts including the common bean (Phaseolus vulgaris). To identify potential sources of resistance, screening material was chosen from an Andean Diversity Panel (ADP) based on yield data. Twenty four genotypes were grown in a growth chamber at 22oC and inoculated with an AG4 R. solani isolate 14 days after planting. Fourteen days after inoculation, roots were harvested and rated on a scale of 0 (no disease) to 6 (plant dead) and a disease index (DI) calculated. Sixteen phenotypic traits were compared to DI using a correlation matrix and only seed weight was determined to have a significant correlation to DI. These 24 genotypes were mapped onto a neighbor joining tree of 503 ADP lines that had been generated from 4416 SNP markers. Four of the genotypes with the lowest average DI were found to be located within a single clade. Eight genotypes were selected from this clade based on seed weight and screened for disease response as above. Of these eight lines, five (63%) showed reduced disease severity which is an improvement over selection based solely on yield in which only 8 out of the original 24 lines (33%) showed reduced disease severity. Therefore, this correlative approach could provide a promising method for more effectively focusing screening efforts.