Oil and seed yield stability in a worldwide collection of safflower under arid environments of Iran

Abstract

The genotype × environment interaction (GEI) have direct impact on stability of genotypes grown under varied environmental conditions. In the present study, the additive main effects and multiplicative interaction (AMMI) model was employed to investigate GEI, stability and adaptation of a worldwide germplasm of safflower (Carthamus tinctorius L.) for seed and oil yield. The experiments were conducted at seven environments (combination of location, year and irrigation regimes) using 100 safflower genotypes. The results of the AMMI analysis showed that the main effects due to genotype, environment, and GEI as well as the first four interaction principle component axes were significant for both seed and oil yield. Environment was the major source of variability, followed by GEI. The results of AMMI biplot and stability parameters including AMMI stability value (ASV), sum of the absolute value of IPC scores (SIPC) and genotype selection index (GSI) revealed that genotypes G60 (originating from Jordan) and G90 (originating from Kerman, Iran) had general adaptation under drought and normal conditions. Genotype G21, originating from Greece, exhibited high adaptation and yield under the normal environments. The AMMI biplot determined genotypes G65 (originating from USA) and G40 (originating from Tajikistan) as the superior to be grown under drought stress conditions. The results eventually indicated that the AMMI biplot is an informative method to explore the stability and adaptation patterns of genotypes in practical plant breeding.