Abstract

This study was carried out to assess the nature and magnitude of genotype-environment interaction (GEI) and the correlation among some stability parameters. Eleven potato genotypes were evaluated during 2011 rainfed season at three locations with Randomized Complete Block design with three replications in Amhara region. Combined analysis of variance indicated that the main effect due to location, genotype and genotype by environment interaction were highly significant. Location and genotype were the most important source of variation accounted for 46.51 and 33.82% of the total variance respectively. The GxE interaction was further partitioned using GGE biplot model. The first two principal components obtained by singular value decomposition of the centered data of total starch yield (t/ha) explained 96.8% of the total variability caused by (G+GE). Out of these variations PC1 and PC2 accounted 81 and 15.8% respectively. GGE biplot view across test environments indicated that E1 (Adet) was ideal test location. The stability analysis identified Guassa as more stable and high yielder genotype and recommended for commercial production for Amhara region. Significant (P<0.01) and positive correlations were found among, Wi and ASV, implying that anyone of these parameters could be used to describe genotype stability.

Key words: Potato (Solanum tuberosum L.), genotype plus genotype by environment biplot, genotype- environment interaction, principal component, stability parameters.