Flax (Linum usitatissimum L.) is a common commercial crop that is widely cultivated for fibre, oil and medicinal products globally. To select flax varieties with lead (Pb) tolerance and explore the associated tolerance mechanism under Pb stress, 19 flax varieties were grown using a hydroponic method with added Pb(NO₃)₂. Our results showed that L. usitatissimum ‘Milas’ displayed the highest tolerance to Pb stress, whereas L. usitatissimum ‘Yuan 2000’ was the most sensitive variety under 1 mM of Pb(NO₃)₂. ‘Milas’ accumulated lesser Pb than ‘Yuan 2000’. In addition, under Pb stress, the activities of peroxidase (POD) and superoxide dismutase (SOD) were higher in ‘Milas’ than in ‘Yuan 2000’, whereas the malondialdehyde (MDA) content of the aerial part and the root were lower in ‘Milas’ than in ‘Yuan 2000’. The expression levels of heavy metal stress-related genes were higher in ‘Milas’ than in ‘Yuan 2000’. Our results provide information about breeding flax varieties with Pb tolerance and the mechanisms underlying the response to Pb stress.

亚麻（Linum usitatissimum L.）是一种常见的商业作物，在全球范围内广泛用于纤维，石油和医药产品。为了选择具有铅（Pb）耐受性的亚麻品种并探索在铅胁迫下的相关耐受机制，使用水培法通过添加Pb（NO ₃）₂种植了19个亚麻品种。我们的研究结果表明，L. usitatissimum “米拉斯”显示的最高耐受Pb胁迫，而L. usitatissimum “元2000”是下的Pb 1mM的最敏感品种（NO ₃）₂。“ Milas”积累的铅低于“ Yuan 2000”。此外，在铅胁迫下，'Milas'中的过氧化物酶（POD）和超氧化物歧化酶（SOD）的活性高于'Yuan 2000'，而地上部分和根的丙二醛（MDA）含量较低。 “ Milas”要比“ Yuan 2000”好。“ Milas”中重金属胁迫相关基因的表达水平高于“ Yuan 2000”。我们的结果提供了有关对铅具有耐受性的亚麻品种育种的信息以及对铅胁迫响应的潜在机制。