盐碱复合胁迫对白茎盐生草种子萌发的影响

Effects of salt-alkali mixed stresses on the seed germination of Halogeton arachnoideus

为了解盐碱胁迫对种子萌发的影响,本研究以白茎盐生草(Halogeton arachnoideus)为研究对象,采用室内模拟试验,以盐分种类和盐浓度为控制因素,按照NaCl∶Na2SO4∶NaHCO3∶Na2CO3的顺序,以A (1∶1∶0∶0)、B (1∶2∶1∶0)、C (1∶9∶9∶1)、D (1∶1∶1∶1)、E (9∶1∶1∶9) 5种不同比例进行混合,共5个组别,记为A-E;每个组别分为6个浓度,共30个处理,研究盐碱复合胁迫对其种子萌发的影响。结果表明:随着盐溶液浓度的升高,种子发芽率、发芽势、发芽指数均呈下降趋势;将盐溶液中未萌发的种子转移到蒸馏水中后,种子可以不同程度地恢复萌发。经过回归分析得出,A-E的耐盐阈值依次为0.26、0.24、0.23、0.25、0.16 mol·L^(-1),耐盐极限值分别为0.65、0.62、0.62、0.60、0.52 mol·L^(-1);聚类分析得出,A-E的耐盐阈值依次为0.3、0.2、0.3、0.3、0.1 mol·L^(-1)。对回归与聚类分析结果取均值,得出白茎盐生草种子萌发在盐碱复合胁迫下的耐盐阈值为0.234 mol·L^(-1),耐盐极限值为0.602mol·L^(-1)。盐分浓度对种子萌发的影响大于盐分种类。相较于碱性盐,白茎盐生草更耐受中性盐环境。

To study the influence of salt-alkali stresses on seed germination, indoor simulations were performed on Halogeton arachnoideus to investigate the effect of salt-alkali mixed stresses on seed germination, taking salt type and concentration as control factors. Following the sequence NaCl∶Na2SO4∶NaHCO3∶Na2CO3, mixed in 5 different ratios, we had 5 experimental groups, A-E. Each group was divided into 6 concentrations, for a total of 30 treatments. The results indicate that as salt concentrations increased, the seed germination percentage, germination potential, and germination index of seeds decreased. The seeds that did not germinate in the salt solution were transferred to distilled water, and the seeds of different degrees could resume germination. Via regression analysis, we found the salt tolerance thresholds of A-E to be0.26, 0.24, 0.23, 0.25, 0.16 mol·L^(-1) and the salt tolerance limits of 0.65, 0.62, 0.62, 0.60, 0.52 mol·L^(-1), respectively. Cluster analysis showed that the salt tolerance thresholds of A-E were 0.3, 0.2, 0.3, 0.3 and 0.1 mol·L^(-1), respectively. The mean value of regression and cluster analysis results showed that the salt tolerance threshold of H. arachnoideus seed germination under mixed salt-alkali stresses was 0.234 mol·L^(-1), while the salt tolerance limit was 0.602 mol·L^(-1). The effect of salt concentration on seed germination was larger than that of the salt species. Compared with alkaline salt, H. arachnoideus was more tolerant to a neutral salt environment.