红砂种子萌发对盐胁迫及适度干旱的响应

对红砂（Reaumuria soongorica (Pall.) Maxim）种子进行室内萌发实验,采用双因素正交法,设置NaCl 10个梯度(mmol·L-1):0、25、50、75、100、125、150、175、200、250;以PEG模拟干旱胁迫两个PEG浓度（g·L-1）: 0和75,测定种子萌发的12个指标,分析红砂种子萌发对NaCl胁迫及适度干旱的响应。结果表明,盐胁迫降低红砂种子萌发的发芽率,减弱种子活力,抑制胚根和胚轴生长。然而一定程度干旱胁迫（PEG75 g·L-1）可提高种子发芽率,增大种子活力,促进干重累积。耐盐隶属函数分析显示, PEG75处理下红砂种子的耐盐性高于PEG0,由此推测红砂进化出了盐胁迫与干旱胁迫的交叉适应策略。

Responses of Reaumuria soongorica Seed Germination to Salt Stress and Moderate Drought

Experiment on response of Reaumuria soongorica seed germination to drought stress and moderate drought was conducted in laboratory. Using the two-factor orthogonal method, we set 10 NaCl treatments ranging from 0 to 250 mmol·L-1, and 2 PEG grads, 0 g·L-1 and 75 g·L-1. 12 germination indexes were measured. Results showed that germination rate of R. soongorica decreased, seed vitality reduced, and radical length as well as hypocotyl length was inhibited by NaCl stress. However, moderate drought could raise germination rate, increase seed vitality, and promote dry weight to accumulate. Salt-proof membership function analysis revealed that R. soongorica had evolved cross-adaptation strategy to resist salt stress and drought stress.