Recent studies have shown that nocturnal irradiation of rose plants (Rosa × hybrida) with weak irradiation intensity ultraviolet B (UV-B) can prevent infection caused by several pathogens. However, the effects of this low UV-B irradiation at night on the appearance and edible functionality including antioxidant activity of rose flowers have not yet been investigated. Here, UV-B lamps were placed at varying distances in greenhouses, resulting in low (0–0.8 μW/cm2), medium (0.8–4.0 μW/cm2), and high (4.0–8.0 μW/cm2) UV intensities on the top of the plants, and the effects of UV-B irradiation on flower color and antioxidant activity using 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay were investigated. In Experiment 1, the correlation between antioxidant activity and total polyphenol content in petal between 10 different rose cultivars, as well as the correlation between antioxidant activity and each anthocyanin or flavonol, were investigated. The results showed a strong correlation between antioxidant activity and total polyphenol content (R = 0.969), as well as between antioxidant activity and cyanidin-3,5-diglucoside content (R = 0.731). However, antioxidant activity was not correlated with the content of cyanidin-3-glucoside or each flavonol in the petals. Therefore, the antioxidant activity of rose flowers may be determined by their total polyphenol content rather than anthocyanin or flavonol content. In Experiment 2, the correlation between antioxidant activity and total polyphenol content was investigated using UV-B–irradiated rose flowers. The results showed a high correlation between these two parameters (R = 0.84). Among the five cultivars used in this experiment, ‘Crimson Glory’ showed a decrease in total polyphenol content and antioxidant activity with increasing UV-B intensity. For other cultivars, UV-B irradiation had little effect on polyphenol content and antioxidant activity. The effect of weak night-time UV-B irradiation, used for disease and insect control, on the total polyphenol content that determines the antioxidant activity of rose petals varied between cultivars. However, the effect was limited and did not affect the quality as an edible flower.

中文翻译：

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夜间紫外线 B 处理可以防止食用玫瑰花受到植物病害的影响，而不会改变外观和多酚含量


最近的研究表明，夜间照射强度较弱的紫外线 B （UV-B） 的玫瑰植物 （Rosa × hybrida） 可以防止由多种病原体引起的感染。然而，这种夜间低 UV-B 照射对玫瑰花的外观和食用功能（包括抗氧化活性）的影响尚未得到研究。在这里，UV-B 灯在温室中以不同的距离放置，导致植物顶部产生低 （0-0.8 μW/cm2）、中等 （0.8-4.0 μW/cm2） 和高 （4.0-8.0 μW/cm2） 紫外线强度，并使用 2,2'-联氮基-双（3-乙基苯并噻唑啉-6-磺酸）自由基清除测定研究了 UV-B 照射对花色和抗氧化活性的影响自由基清除测定。在实验 1 中，研究了 10 个不同玫瑰品种之间抗氧化活性与花瓣中总多酚含量之间的相关性，以及抗氧化活性与每种花青素或黄酮醇之间的相关性。结果表明，抗氧化活性与总多酚含量 （R = 0.969） 以及抗氧化活性与矢车菊素-3,5-二葡萄糖苷含量 （R = 0.731） 之间存在很强的相关性。然而，抗氧化活性与花瓣中矢车菊素-3-葡萄糖苷或每种黄酮醇的含量无关。因此，玫瑰花的抗氧化活性可能由其总多酚含量决定，而不是由花青素或黄酮醇含量决定。在实验 2 中，使用 UV-B 照射的玫瑰花研究了抗氧化活性与总多酚含量之间的相关性。结果显示这两个参数之间具有高度相关性 （R = 0.84）。 在本实验中使用的五个品种中，'Crimson Glory' 显示总多酚含量和抗氧化活性随着 UV-B 强度的增加而降低。对于其他品种，UV-B 辐照对多酚含量和抗氧化活性影响不大。用于疾病和昆虫控制的弱夜间 UV-B 照射对决定玫瑰花瓣抗氧化活性的总多酚含量的影响因品种而异。然而，效果有限，不影响作为可食用花的质量。