Spatial and temporal patterns of associations between quantitative characters and resistance to scald in barley

Abstract

Interrelationships of two character sets, quantitative characters and resistance to Rhynchosporium secalis, were studied in a world barley collection and in an experimental barley population, Composite Cross II (CCII). The characters within each set were found to be more closely correlated with each other than they were with characters in the other set. Canonical correlation analysis showed that the correlations between sets as a whole were substantial; almost every character contributed, to a larger or lesser extent, to the correlation between these two sets of characters in the world barley. The associations of these characters among accessions from four geographical regions were also studied, and these showed that geographical regions differed strikingly in patterns of both within‐ and between‐set correlations. The within‐set correlations for North African accessions appeared to be of the same order of magnitude as the between‐set associations; whereas within‐set correlations were much larger than between‐set associations for the other three regions. No marked correlations between these two sets of characters were detected in various generations of CCII. Copyright © 1991, Wiley Blackwell. All rights reserved