NaCl胁迫对甘肃省不同地区盐生草种子萌发特性的影响

Effects of NaCl stress on seed germination of Haloge⁃ ton glomeratus in different regions of Gansu Provience

摘要:

对采集自甘肃省 17 个地区的盐生草(Halogeton glomeratus)种子进行萌发期的盐胁迫试验， 测定种子发芽指标、幼苗生长指标、离子含量以及根系活力，研究 NaCl 胁迫对不同地区盐生草种子萌发特性的影响。结果表明：盐胁迫下，17 个地区的盐生草种子的发芽率和发芽势均降低，其中，12 和 15 号地区盐生草种子的萌发率最高，分别为对照的 88. 20% 和 91. 92%，3 号和 17 号地区盐生草的萌发率最低，分别为对照的 74. 98% 和 73. 85%；各地区盐生草幼苗的株高对盐胁迫的响应不同，有 6 个地区盐生草的株高增大，其他地区的株高受到不同程度的抑制，其中 17 号地区盐生草株高受抑制最严重，为对照的 82. 35%。盐胁迫处理下，有 9 个地区的盐生草幼苗鲜重高于对照，其他地区的幼苗鲜重均低于对照；与对照相比，盐生草幼苗的干重明显升高，升幅最高的是白银市靖远县的盐生草品种，达到 200. 48%，最低的是民勤县收成乡的盐生草品种，为 112. 98%；分别测定两个发芽状况最好和最差的盐生草幼苗的离子含量，发现盐胁迫下盐生草幼苗的 Na⁺含量增多、K⁺含量减少，K⁺/Na⁺显著降低；根系活力分析发现，盐胁迫对不同地区盐生草幼苗根系活力影响不同，其中，白银市景泰县的盐生草幼苗根系活力受到的影响最大，白银市靖远县的盐生草幼苗根系活力受到的影响最小，但均表现出抑制的效果。17 个地区的盐生草品种可分为耐盐性强、耐盐性较好以及耐盐性差 3 个类群。

Abstract:

Experiments were carried out to evaluate the impact of salt stress on the germination of Halogeton glomeratus seeds collected from 17 regions in Gansu Province. The index of seed germination and growth，ion content and root activity were determined. The results showed that the germination rate and germination potential of H. glom- eratus in 17 regions decreased under salt stress. The germination rate of H. glomeratus in Minqin Zhongxing and Lan‐ zhou Xinqu regions were the highest，which was 88. 20% and 91. 92% of the control，respectively. The germination rate of H. glomeratus in Jiuquan and Minle region were the lowest，which reached 74. 98% and 73. 85%，respec‐ tively. The response of plant height of H. glomeratus seedlings to salt stress was different in different regions. The plant height of H. glomeratus seedlings in 6 regions became higher and in other regions was inhibited to varying de‐ grees. The plant height of H. glomeratus seedlings in Minle region was 82. 35% of the control which was the most se‐ verely inhibited. The fresh weight of H. glomeratus seedlings in 9 regions was higher than that of the control under salt stress. Compared with the control，the dry weight of H. glomeratus seedlings increased significantly. The highest was reaching 200. 48% in Dalu town，while the lowest reached 112. 98% in Minqin Harvest region. In the three groups of repeated data of the germination rate of H. glomeratus in each region，the mean value of the two groups with similar germination rate was taken as the basis. H. glomeratus seeds from two regions with the best germination and two regions with the worst germination were screened and the ion content of their seedlings was determined. The results show that under salt stress，the content of Na⁺ of H. glomeratus seedings increased，the content of K⁺ de‐ creased，and K⁺/Na⁺ decreased significantly. The root activity analysis showed that salt stress had different effects on the root activity of H. glomeratus seedlings in different regions. Compared with the control，the root activity of H. glomeratus in Jingtai decreased by 84. 6%，which was the most significant decrease. The root activity of H. glomera- tus in Dalu town decreased by 9. 5%，which was the least. Both of them were inhibited. The cumulative contribution rate of the first three principal components was 72. 40% by principal component analysis of the six traits. Through cluster analysis，H. glomeratus seeds were divided into three groups in 17 regions： strong salt-tolerance，salttolerance and poor salt‐tolerance. The results of this study provide a theoretical basis for the identification，innovation and utilization of H. glomeratus germplasm resources.