Screening of Safflower Genotypes for Enhanced Flavonoid and Anthocyanin Content under Water-Limited Conditions

Drought is the main abiotic stress limiting safflower production in semi-arid regions, with flavonoid and anthocyanin pathways playing a key role in antioxidant defense. A two-year field experiment in Arak, Iran, evaluated ۳۸ safflower genotypes under full irrigation and terminal drought stress, measuring total flavonoid and anthocyanin contents. Drought increased average flavonoids by ۶.۳% (from ۰.۱۳۹۵ to ۰.۱۴۸۳ mg QE g⁻¹ DW) and anthocyanins by ۸.۱% (from ۰.۰۰۳۸۲ to ۰.۰۰۴۱۳ mg g⁻¹ DW). A three-way ANOVA showed significant effects of irrigation and year on both traits, with year accounting for ۶۲.۸% of anthocyanin variance, while genotype effects were not significant (p = ۰.۹۵۳ and p = ۰.۴۹۶), indicating high residual variability (۷۵.۸% and ۲۳.۲%). Using eight drought-tolerance indices, Variety ۳۱ ranked first for flavonoid stability (STI = ۱.۳۱۱), and Variety ۱۴ ranked first for anthocyanin stability (STI = ۱.۹۵۲). Variety ۱۴ was the only genotype among the top five for both traits. The correlation between flavonoid and anthocyanin contents was weak and non-significant (r = −۰.۰۶, p = ۰.۱۸۷), suggesting independent regulation of these two phenylpropanoid branches. These results introduce Variety ۱۴ as a promising multi-trait parent for drought-resilience breeding and highlight that interannual climatic variation, rather than genotype, is the primary factor influencing anthocyanin accumulation in safflower petals.

کلیدواژه ها:

Anthocyanin ، Drought stress ، Environment interaction ، Flavonoid ، Genotype