Stability Analysis of Seed Yield of Safflower Genotypes (Carthamus tinctorius L.)

The selection efficiency of the most desirable safflower genotypes can be improved by incorporating the graphical methods and statistical analysis. This experiment was carried out to determine grain yield stability of safflower genotypes using the graphical and statistical methods. Twenty safflower genotypes were evaluated in Chachsaran, Choram, Behbehan and Dehdasht using randomized complete block design with three replications in three cropping seasons (2001-2004). The results of simple analysis of variance indicated the significance of genotype effect on grain yield. The results of combined analysis of variance revealed significance of genotype, environment, genotype × environment interaction and linear genotype × environment interaction effects. Since the genotype × environment interaction effect was significant, seven stability statistics including Si, CV, Wi2, &sigmai2, bi, Sdi2 and Sdi were calculated for stability analysis and the results indicated genotype 3 (PI250536-2) had the highest grain yield stability. The results of AMMI (Additive main effect and multiplicative interaction) model showed that 98.74% of total genotype ×environment interaction variation was due to four principle components (PCs). Based on the above statistics and the biplots derived from AMMI analysis, genotypes 3 (PI250536&minus2), 10 (Syrian hama 1), 14 (Saffir) and 16 (PI 251268) had grain yield stability. These genotypes were identified as suitable and adapted genotypes with grain stability for the studied environments.