Yield and yield component response of barley in subarctic and temperate environments

Abstract

Plant breeders are continually searching for new sources of genetically diverse germplasm from which superior genotypes might be developed. The objective of this study was to assess the performance of subarctic- and temperate-adapted barley cultivars when grown in reciprocal areas of adaptation to determine their potential for use in breeding programs. Four subarctic-adapted and four temperature-adapted barley (Hordeum vulgare L.) cultivars were grown at two environments each in Alaska (subarctic) and Nebraska (temperate) for 2 yr. Subarctic-adapted cultivars were earlier heading and earlier maturing in both environments, although differences were larger in subarctic environments. Grain yield of the two classes of cultivars was similar in subarctic environments, but temperate-adapted cultivars were far superior when grown intemperate environments. Kernel weight of all cultivars was higher in subarctic environments than in temperate environments. Maturity differences alone did not account for the poor performance of subarctic-adapted cultivars in temperate environments. Yield was positively correlated with all three yield components in temperate environments, but only with spikes per square meter in subarctic environments. Results from this study suggest that greater potential exists for the utilization of temperate-adapted germplasm to favourably increase the genetic diversity of subarctic-adapted germplasm than vice versa.Key words: Barley, Hordeum vulgare L., adaptation, yield components