|Jung, Hans joachim|
Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract only
Publication Acceptance Date: 10/20/1997
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Breeding for increased forage digestibility typically involves a decrease in lignin concentration. Because lignin is often involved in protecting plants from fungal disease attack, such a change might reduce a plant's inherent resistance to fungal pathogens. Clones from four populations of smooth bromegrass have been divergently selected for lignin and etherified ferulic acid concentration. The objective of this research was to assess the role of lignin and ferulic acid in resistance of smooth bromegrass (Bromus inermis) to crown rust (Puccinia coronata). Significant differences among populations and clones within populations were found for all measures of disease. Surprisingly, decreased lignin concentration was associated with increased resistance to P. coronata: 40% fewer pustules, 47% smaller pustules, and 57% less diseased leaf area. Five of 16 low lignin clones were immune to P. coronata. Ferulic acid did not appear to have an effect on disease resistance. Linkage disequilibrium, caused by unconscious selection for crown rust resistance during selection for low lignin concentration, may explain these results.