Stability analysis and genotype environment interaction for grain yield in bread wheat

The objective of this study was to determine stability and genotype X environment interaction of some wheat genotypes and the effect of different environments on grain yield to understand their adaptation to varying environments. Forty wheat genotypes were evaluated at three locations (Gemmieza Nubaria and Mallawy) in Egypt during 2008/2009 and 2009/2010 seasons. Genotypes generally showed variation in their response to changing environment. Combined analysis of variance revealed highly significant variances (P 0.01) due to genotypes (G) locations (L) years (Y) the first order interactions (G x L G x Y an Y x L) and the second order interaction (G x L x Y) for grain yield. Maximum grain yield was produced in Ge eza followed by Mallawy and Nubaria locations. Pooled analysis of variance and stability ysis were performed. The variances due to genotypes (G) environments (E) E + (G x E) G x E E (linear) G x E (linear) and pooled deviation were highly significant (P 0.01). The partitioning of G x E interactiion variance into linear and non-linear components indicated that both predictable and unpredictable components shared the interaction. Wide range of stability statistics was observed among genotypes for all the stability parameters. Maximum grain yield of 21.16 (ardab/feddan) was produced by the promising line 32 followed by the promising 33 28 23 Sakha 93 and Gemmieza 9. The large variation in mean grain yield, phenotypic variance (ó2p) coefficient of variation (C.V. %) regression coefficient (bi) and deviation from regression (S2d) indicates different responses of genotypes to environmental changes. Genotypes Sakha 93 and the promising lines 23 31 and 32 showed high grain yield low deviation. frog regression and their regression coefficient values were close to unity and could be classified as stable genotypes. Stable performance was expressed by the promising line. 32 (Gemmieza 9 / Sids 8) bemuse of higher grain yield (x