Lavandula genus is a considerable medicinal plant in pharmaceutical and cosmetics industries. Considering increasing threat of drought in the world, it is important to identify genotypes which can tolerate drought. It is also important to characterize quantity and quality of essential oils, and tolerance indicators of these genotypes against drought stress. Therefore, an experiment was conducted in Gorgan University of Agricultural Sciences and Natural Resources, Iran, during 2017 and 2018, to investigate these factors. It was a factorial experiment based on randomized complete block design with two treatments, three genotypes (Lavandula angustifolia cv. Hidcote, Lavandula angustifolia cv. Munstead, and Lavandula stricta), and four levels of drought stress (irrigation regimes) (I₁: 100–90% (control), I₂: 80–70%, I₃: 60–50% and I₄: 30–40% of field capacity) which was done with three repetitions. Drought increased amount of proline in leaves, antioxidant activity, activity of catalase, peroxidase, ascorbate peroxidase, and superoxide enzymes, malondialdehyde content, total flavonoids, total phenol, total sugar and essential oil percentage. The PCA analysis of different irrigation regimes showed that in the first component, the best traits are antioxidant enzymes CAT, SOD, APX, while in the second component, only the trait Catalase is the best trait. The results of PCA analysis in lavender genotypes showed that L. stricta exhibits the most affected physiological changes while trying to adjust to changes in the water status of the environment, under the imposed conditions and shows the highest resistance. But it reduced dry weight of aerial parts, relative water content of leaves, and efficacy of essential oil. Lavandula stricta genotype had the highest amount of essential oil, but the highest dry weight of the aerial parts and essential oil yield were related to L. angustifolia cv. Hidcote and L. angustifolia cv. Munstead genotypes. In all evaluated genotypes, with increasing drought stress, monoterpene compounds were decreased and sesquiterpene compounds were increased. Totally it was shown that drought effect on evaluated traits depends on genotype and nature of traits; this indicates that by choosing drought-tolerant genotypes in breeding programs, high quantity and quality of essential oil, as well as tolerance to drought stress can be achieved.

薰衣草属是制药和化妆品行业的重要药用植物。考虑到世界干旱威胁日益增加，确定能够耐受干旱的基因型非常重要。表征精油的数量和质量以及这些基因型对干旱胁迫的耐受性指标也很重要。因此，2017 年和 2018 年在伊朗戈尔甘农业科学与自然资源大学进行了一项实验，以调查这些因素。这是一项基于随机完全区组设计的析因试验，采用两种处理方法、三种基因型（狭叶薰衣草cv. Hidcote、狭叶薰衣草cv. Munstead 和狭叶薰衣草）)，以及四种干旱胁迫水平（灌溉制度）（I ₁：100-90%（对照），I ₂：80-70%，I ₃：60-50% 和 I ₄：田间持水量的 30-40% ) 重复三遍。干旱增加了叶片中脯氨酸的含量、抗氧化活性、过氧化氢酶、过氧化物酶、抗坏血酸过氧化物酶和超氧化物酶的活性、丙二醛含量、总黄酮、总酚、总糖和精油百分比。不同灌溉方式的PCA分析表明，在第一组分中，抗氧化酶CAT、SOD、APX的性状最好，而在第二组分中，只有过氧化氢酶是最好的性状。薰衣草基因型的 PCA 分析结果表明，L. stricta在施加的条件下，在尝试适应环境水状态的变化时表现出受影响最大的生理变化，并表现出最高的抵抗力。但它降低了地上部分的干重、叶子的相对含水量和精油的功效。Lavandula stricta基因型的精油含量最高，但地上部分的最高干重和精油产量与L. angustifolia cv.有关。Hidcote 和L. angustifolia简历。芒斯特德基因型。在所有评估的基因型中，随着干旱胁迫的增加，单萜化合物减少，倍半萜化合物增加。总的来说，干旱对评价性状的影响取决于性状的基因型和性质；这表明通过在育种计划中选择耐旱基因型，可以实现高数量和高质量的精油，以及对干旱胁迫的耐受性。