GGE biplot analysis of genotype × environment interaction in wheat-barley disomic addition lines.

Abstract

Identification of the genetic architecture of phenotypic stability and management of adaptational genes are prerequisites for improvement of plant adaptation. To locate the genes controlling adaptation in barley, wheat-barley disomic addition lines were used in a randomized complete block design with three replications under rainfed and irrigated conditions for three consecutive cropping seasons (2009-2011). The GGE [genotype main effect (G) and genotype by environment interaction (GE)] biplot graphical tool was applied to analyze multi-environment trials (MET) data. Combined analysis of variance showed that the GE interaction effect accounted for 57.3% of total variation, indicating that the GE interaction is more complex. The first two principal components (PC1 and PC2) were used to display a two-dimensional GGE biplot. Thus, genotypic PC1 scores >0 classified the high yielding genotypes while PC1 scores <0 identified low yielding genotypes. Unlike genotypic PC1, genotypic PC2 scores near zero exhibited stable genotypes whereas large PC2 scores discriminated the unstable ones. The GGE biplot analysis was useful in identifying stable genotypes with high yield performance. Disomic addition line (DAL) H7, was characterized as genotype with the highest mean yield and low stability. In contrast, DAL H2, was identified as the best genotype in integrating mean yield with the highest stability performance. It was concluded that most of the genes controlling yield and yield stability in barley are located on chromosome H2.