This study aimed to examine the effects of the exogenous application of ascorbic acid (ASA) on the growth and pigment content of Calendula officinalis L. flower heads under salinity stress. A pot experiment performed as a 5 × 3 × 4 factorial based on a completely randomized design (CRD) to evaluate the response of marigold to ASA foliar application (0, 3, and 6 mM) under five salinity levels (0, 25, 50, 75, and 100 mM NaCl). ASA foliar application on plant growth parameters, carotenoid, total phenolic, total flavonoids, flavonol content, the antioxidant activity of the flower heads, proline content of leaves, cell membrane injury, and water content under salinity stress investigated. The results indicated that ASA and NaCl levels had significant effects on all studied characteristics, and ASA application was practical to mitigate the adverse effect of NaCl stress. By increasing NaCl levels, the growth, dry matter, carotenoid, flavonoid, and flavonol contents of marigold flowers were decreased; these characteristics increased by ASA application (especially 6 mM). While by increasing NaCl, the proline and total phenolic contents, antioxidant activity, and cell membrane injury increased, and these traits decreased by using ASA. At the highest NaCl concentration (100 mM), application of 6 mM ASA increased total dry biomass, dry matter of flower, carotenoid, total phenolic, and flavonoid content of the flower by 51.11%, 2.71%, 1.63%, 31.5%, and 1.65%, respectively. Whereas by using 6 mM ASA at 100 mM NaCl concentration, antioxidant activity, proline content, and cell membrane injury decreased by 2.51%, 33.34%, and 6.17%, respectively. Therefore, using 6 mM, ASA had more effective influences than 3 mM. Foliar ASA spraying enhanced secondary metabolites of marigold. Also, ASA application helped the plants resistant to salt stress by several mechanisms, including increasing proline and cell membrane stability.

本研究旨在研究外源施用抗坏血酸 (ASA) 对金盏花生长和色素含量的影响。L. 盐分胁迫下的头状花序。基于完全随机设计 (CRD) 作为 5 × 3 × 4 因子进行的盆栽试验，以评估万寿菊在五种盐度水平（0、25、50 、75 和 100 mM NaCl)。ASA 叶面喷施对植物生长参数、类胡萝卜素、总酚、总黄酮、黄酮醇含量、花头的抗氧化活性、叶片脯氨酸含量、细胞膜损伤和盐分胁迫下的水分含量进行了研究。结果表明 ASA 和 NaCl 水平对所有研究的特性都有显着影响，并且 ASA 的应用可以减轻 NaCl 胁迫的不利影响。通过增加NaCl水平，金盏花的生长、干物质、类胡萝卜素、黄酮和黄酮醇含量降低；这些特性随着 ASA 的应用（尤其是 6 mM）而增加。而通过增加NaCl，脯氨酸和总酚含量、抗氧化活性和细胞膜损伤增加，而使用ASA降低这些性状。在最高 NaCl 浓度 (100 mM) 下，施用 6 mM ASA 使花的总干生物量、干物质、类胡萝卜素、总酚和类黄酮含量增加 51.11%、2.71%、1.63%、31.5% 和分别为 1.65%。而通过在 100 mM NaCl 浓度下使用 6 mM ASA，抗氧化活性、脯氨酸含量和细胞膜损伤分别降低了 2.51%、33.34% 和 6.17%。因此，使用 6 mM，ASA 比 3 mM 具有更有效的影响。叶面喷洒 ASA 增强了万寿菊的次生代谢产物。还，