Drought is a main stressor affecting plant production worldwide. Safflower (Carthamus tinctorius L.) is known to exploit biochemical strategies to tolerate drought stress. However, the little so far known about these strategies does not guarantee safflower yield stability in future. To fill the gap, changes in the biochemical traits and antioxidant activities of safflower were monitored using 100 genotypes under the two non-stress and drought-stress field conditions in two subsequent years (2017 and 2018). While drought stress was observed to give rise to reversible increases in total phenolics (TPC), total flavonoids (TFD), total flavonols (TFL), total anthocyanin (Ant), proline, malondialdehyde (MDA), and antioxidant activity, it decreased total chlorophyll (ChlT) and total carotenoid (Car) contents in safflower. Under drought stress, the highest values for TPC (21.55 16.07 mg GAEg⁻¹ fresh weight [FW]), Car (0.08 mg g⁻¹ FW), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity (98%) were measured in G₁₆, averaged over the two study years. Also the highest values for TFD (5.17 mg QEg⁻¹ FW), TFL (1.99 mg QEg⁻¹ FW), Ant (234.1 µmol g⁻¹ FW), ChlT (0.67 mg g⁻¹ FW), and proline (851 μmol g ⁻¹ FW) were recorded for G₈₀, G₆₀, G₂₃, G₆₂, and G₃₃. The least MDA content (2.8 µmol g⁻¹ FW) was denoted to G₉₁ under drought stress. The results of both principal component and correlation analyses demonstrated the effective role of total flavonoids in safflower drought tolerance. The high genetic variance was seen to result in the high heritability of biochemical traits under drought stress, thereby improving drought tolerance in safflower cultivated in drought prone regions. The significant genetic variations in all the biochemical traits indicated that these traits, especially TPC and TFD, could be used as screening criteria for genotypic selection in arid climates.

干旱是影响全球植物生产的主要压力源。红花（红花L.）可以利用生化策略来耐受干旱胁迫。但是，迄今为止对这些策略知之甚少并不能保证将来的红花产量稳定。为了填补这一空白，在随后的两年（2017年和2018年）的两个非胁迫和干旱胁迫条件下，使用100个基因型监测了红花的生化性状和抗氧化活性的变化。虽然观察到干旱胁迫导致总酚类（TPC），总黄酮类（TFD），总黄酮醇（TFL），总花色苷（Ant），脯氨酸，丙二醛（MDA）和抗氧化剂活性可逆地增加，但总含量却降低了红花中的叶绿素（ChlT）和总类胡萝卜素（Car）含量。在干旱胁迫下，TPC最高（21.55 16.07 mg GAEg ^-1在G ₁₆中测量了这两个研究年的平均值，得出汽车的新鲜重量[FW]，汽车（0.08 mg g ^-1 FW）和2,2-二苯基-1-吡啶并肼基（DPPH）活性（98％）。同样是TFD（5.17 mg QEg ^-1 FW），TFL（1.99 mg QEg ^-1 FW），Ant（234.1 µmol g ^-1 FW），ChlT（0.67 mg g ^-1 FW）和脯氨酸（851μmol）的最大值记录了G ₈₀，G ₆₀，G ₂₃，G ₆₂和G _33的g ^-1 FW）。最小的MDA含量（2.8 µmol g ^-1 FW）表示为G ₉₁在干旱的压力下。主成分和相关分析的结果均表明总黄酮在红花抗旱性中的有效作用。较高的遗传方差被认为导致干旱胁迫下生化性状的高遗传力，从而提高了在干旱多发地区种植的红花的耐旱性。所有生化特性的显着遗传变异表明，这些特性，尤其是TPC和TFD，可以用作干旱气候中基因型选择的筛选标准。