Genetic Improvement in Grain Yield and other Traits of Wheat Grown in Western Canada

Abstract

Breeding efforts have been important in addressing the challenges of wheat production in western Canada. We studied the effect of breeding on grain yield and other important traits of 100 wheat cultivars released in Canada from 1885 to 2012. The cultivars were grown in seven environments during 2011 to 2013. Grain yield was positively correlated with days to maturity and kernel weight but negatively correlated with plant height, lodging, and grain protein content. Results indicate that grain yield increased at a rate of 0.28% year–1 in 62 cultivars of Canada western red spring (CWRS) class, 1.2% year–1 in 9 cultivars of Canada prairie spring (CPS) class, but not in 14 studied cultivars of Canada western amber durum (CWAD) class due to breeding efforts. Grain protein content exhibited an increasing trend in cultivars of CWRS (0.05% year–1) and CPS (0.79% year–1) classes, and a decreasing trend in those of CWAD (0.23% year–1). Days to maturity decreased in CWRS (0.02% year‐1) and CWAD (0.09% year‐1) classes but remained unchanged in CPS class. Plant height exhibited a gradual decline in cultivars of CWRS (0.16% year–1) and CWAD class (0.44% year–1), but an increase in those of CPS class (0.50% year–1). Test weights showed an increasing trend in CWRS (0.04% year–1) and CPS (0.17% year–1) classes but not in CWAD class. Grain weight also increased over time in CWRS (0.06% year–1) and in CPS (0.41% year–1), but not in CWAD class. These results suggest that breeding efforts have improved yield, quality and other attributes in wheat cultivars of different Canadian wheat classes over the last 100 years.