水分胁迫下不同抗旱类型胡麻苗期生理生化指标变化

采用盆栽人工控水方法,研究了不同水分处理对苗期胡麻叶片相对含水量(RWC)、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性以及过氧化产物丙二醛(MDA)含量和游离脯氨酸(Pro)含量的影响。结果表明:在干旱胁迫下,不同抗旱类型的胡麻品种RWC均有不同程度的降低,在中度和重度胁迫下,RWC平均比CK降低4.36%和13.74%,即随胁迫强度的增加RWC下降幅度变大,强、弱抗旱性品种平均比CK降低7.67%和10.42%,即抗旱性强的品种RWC下降幅度相对较小;抗旱性强的品种其CAT和POD活性在中度和重度胁迫下平均比CK升高12.46%、15.14%和65.01%、156.01%,均随胁迫的增强而增加,但抗旱性弱的品种却为46.84%、29.85%和58.73%、38.20%,呈现先增后减的趋势;MDA含量均随胁迫加剧呈上升趋势,但抗旱性强的品种MDA含量随胁迫的增强增幅较小,为2.99%;Pro含量随水分胁迫程度的加剧不断增加,且抗旱性强的品种体内游离脯氨酸积累量较高,平均升高108.64%。RWC和Pro可作为胡麻苗期抗旱性鉴定的生理指标。

Physiological and biochemical characteristics of drought resistance for oil flax at seedling stage under water stress

This article reports the influence of water on oil flax leaf relative water content(RWC), activity of catalase (CAT) and peroxidase (POD), content of lipid peroxidation products malondialdehyde (MDA) and free proline (Pro) at the seedling stage, using pot experiments with three water treatments. The results showed that the RWC of different drought resistance varieties have different degrees of reduction. Under the moderate and severe water stress, the average RWC decreased by 4.36% and 13.74% compared with CK, the average RWC of drought-resistant and drought-sensitive varieties respectively decreased by 7.67% and 10.42% compared with CK, the deought-resistant varieties decreased less; and the average CAT and POD activity of drought-resistant varieties increased by 12.46%, 15.14% and 65.01%, 156.01%, respectively. The CAT and POD activity enhanced with the increasing of the stress, but the drought-sensitive varieties increased by 46.84%,29.85% and 58.73%,38.20% compared with CK; it appears increasing at first and then decreasing. The content of MDA increased with the increasing of the stress, while that of drought-resistant had a smaller increase (2.99%) than that of drought-sensitive. The content of Pro increased with the increasing of the water stress, and the drought-resistant varieties had a higher accumulation of the proline; average increase 108.64% compared with CK. Overall, RWC and Pro content can be regarded as physiological and biochemical indexes of drought resistance for oil flax at seedling stage.