Delivering improved varieties for hostile environments: Identification and introgression of genetically different sources of adaptation to low rainfall environments

Abstract

In the low rainfall environments of Australia, yield is commonly reduced and downgrading at receival occurs through poor physical grain quality. Improving yield and physical grain quality through better adaptation to the low rainfall environments is a challenge faced by Australian breeding programs. Germplasm from the Mediterranean basin has historically led to the improvement of adaptation to Australia’s low rainfall environments. Recently, a collaborative partnership with ICARDA has enabled the evaluation of germplasm from the Middle East in Australia, using a national low rainfall trial network. ICARDA have utilised wild barley and primitive landraces to improve adaptation to low rainfall environments, and this germplasm offers a genetically different source of adaptation. Both ICARDA and elite Australian breeding lines have been identified with superior yield and physical grain quality characteristics compared with current varieties using multi-environment trial analysis. Genetic analysis has identified genomic regions associated with improved yield and physical grain quality in the low rainfall environments. The importance of genes associated with developmental patterns in yield under drought stress is highlighted. Barley improvement in the low rainfall environments is discussed from the perspective that international germplasm from similar low rainfall target environments are important sources of traits and genes for improved adaptation.