Grain yield stability analysis of rainfed barley varieties and lines using GGE biplot method

This study was conducted to determine grain yield stability of rainfed promising barley genotypes in six Iranian rainfed research stations (Maragheh، Sararood، Uromieh، Ghamloo، Zanjan and Ardabil) under cold and semi-cold conditions during three cropping seasons (2006-2009). The studied genotypes were 10 promising barley lines along with two checks (one local variety and newly released variety of Abidar). In each environment، the experiment was arranged in randomized complete block design (RCBD) with four replications. Results of combined ANOVA showed that location، year، genotype، interaction oflocation and genotype، and interaction of year، location and genotype had significant effect on grain yield. The genotypes showed the highest and the lowest grain yield in Sararood (2549 Kg/ha) and Zanjan (1578 Kg/ha) stations، respectively. Line No. 9 produced the highest grain yield (2061 Kg/ha). To study the interaction of genotype and environment، GGE biplot method was used. Based on the polygonal graphs related to genotypes، genotype No. 1 (G1) produced the highest yield in Ardabil and genotype No. 5 (G5) showed the highest yield in Zanjan، Maragheh and Uromieh. Besides، genotype 3 (G3) and genotype 4 (G4) produced the highest yield in Ghamloo and Sararood stations، respectively. Based on the theoretical ideal environments graph، Uromieh was closer to the ideal environment. Regarding to the imaginary ideal genotype graph and biplot of genotypes and environments، genotype No. 5 was identified as the best one due to its higher yield and better yield stability.