干旱是影响小麦生产的重要逆境，可以造成萌发成苗质量下降。为了解当前小麦品种在干旱胁迫下的种子萌发特性，采用沙培控水法研究了生产上应用广泛的128个小麦品种的干旱萌发特性；筛选出干旱萌发特性差异显著的6个小麦品种(山农28(SN28)、长6878 (C6878)、烟农19 (YN19)、山农23(SN23)、鑫麦296 (XM296)和新麦38 (XM38))进行干旱胁迫下种子萌发过程中的生理生化分析。结果表明，根据活力指数的耐旱系数进行聚类分析，将128个小麦品种的干旱萌发特性分为好、较好、中等、较差、差5类。山农28和长6878等18个干旱萌发特性好的小麦品种种子萌发快，幼苗整齐健壮；新麦38、乐麦185等26个干旱萌发特性差的小麦品种种子萌发慢、萌发时间分散、发芽率低且幼苗整齐度差。进一步对不同干旱萌发特性的小麦品种进行生理生化指标测定表明，干旱萌发特性好的山农28和长6878干旱萌发前期大分子修复基因TDP1表达水平显著高于对照；干旱萌发前期POD活性也显著高于对照；α-淀粉酶和半胱氨酸蛋白酶活性受干旱影响较小，萌发后期的可溶性蛋白含量显著高于对照。而干旱萌发特性差的鑫麦296和新麦38在干旱胁迫下种胚DNA和蛋白质修复基因表达水平上升相对滞后；在干旱胁迫下的半胱氨酸蛋白酶活性显著降低。上述结果表明，干旱萌发特性好的小麦品种在干旱胁迫下萌发成苗过程中种胚大分子修复能力和种子抗氧化能力强，贮藏物质动员早，最终种子萌发速度快，出苗质量高。
Drought is an important stress affecting wheat production, which can reduce the quality of germination and seedling establishment. In order to understand the seed germination characteristics of wheat cultivars under drought stress, the germination characteristics under drought stress of 128 wheat cultivars widely used in production were identified by sand cultivation and water control method. Six wheat cultivars with significant differences in germination characteristics under drought stress ((Shannong 28 (SN28), Chang 6878 (C6878), Yannong 19 (YN19), Shannong 23 (SN23), Xinmai 296 (XM296), and Xinmai 38 (XM38)) were selected for physiological and biochemical analysis during seed germination under drought stress. The results showed that the germination characteristics under drought stress of 128 wheat cultivars were divided into 5 categories according to the drought tolerance coefficient of vigor index: good, the better, medium, the worse, and the worst. Eighteen wheat cultivars with good germination characteristics under drought stress, including SN28 and C6878, had fast seed germination and healthy seedlings. 26 wheat cultivars with poor germination characteristics under drought stress, such as XM38 andLemai 185, had slow seed germination, dispersed germination time, low germination percentage (GP), and poor seedling uniformity. The physiological and biochemical indices of wheat cultivars with different germination characteristics under drought stress were further determined. The results showed that the relative expression level of TDP1 gene at the early stage of germination under drought in SN28 and C6878 with good germination characteristics under drought stress was significantly higher than the control. POD activity at the early stage of germination under drought was significantly higher than the control. The activities of α-amylase and cysteine protease were less affected by drought, and the soluble protein content at the late stage of germination was significantly higher than the control. However, the relative expression levels of DNA and protein repair genes in seed embryos of XM296 and XM38 with poor germination characteristics under drought stress were relatively delayed under drought stress. The activity of cysteine protease decreased significantly under drought stress. The above results indicated that wheat cultivars with good germination characteristics under drought stress showed strong macromolecular repair ability in seed embryos and antioxidant capacity in seed, early mobilization of storage substances during seed germination and seedling establishment under drought stress, and finally had fast germination speed and high seedling quality.