土培条件下不同盐分梯度对水稻产量及其生理特性的影响

以南粳9108和甬优2640为材料,设置6个土壤含盐量(0%、0.07%、0.14%、0.21%、0.28%、0.35%),研究不同盐分梯度对水稻产量和生理特性的影响。结果表明:(1)盐胁迫影响水稻的生长和发育进程。株高、叶面积、干物质量等形态指标均随盐浓度的上升而下降;稻谷产量亦随盐浓度增加而下降,在0.14%、0.21%、0.28%、0.35%盐浓度处理时产量显著下降,南粳9108分别减产14.14%、43.65%、58.91%、65.68%,甬优2640分别减产20.25%、31.97%、40.41%、49.82%。(2)随着盐浓度的增加,2个参试品种抽穗期叶片抗氧化酶活性均呈先升后降趋势,在0.07%处理下达最高值。(3)抽穗期叶片中游离脯氨酸含量随盐浓度的上升而增加,盐浓度大于0.14%,游离脯氨酸含量较对照显著增加。(4)盐胁迫下,水稻植株吸收Na~+并置换出K~+,除叶片中K~+变化无规律之外,随着盐浓度上升,各部位K~+含量均下降,Na~+含量均上升,K~+/Na~+均呈下降趋势。茎鞘与叶运输的SK、Na随盐浓度的上升而上升,茎选择性运输K~+而抑制Na~+进入叶片;根与茎的SK、Na随盐浓度的上升而下降,茎吸收Na~+并输出K~+到根系。总体而言,低盐浓度对高产水稻品种产量和生理特性无显著影响,盐浓度大于0.07%时影响显著。

Effects of Different Saline Stress on Yield and Physiological Properties of Rice in Soil Culture

In order to study the effects of different saline stress on yield and physiological properties of rice at six salinity gradient (0％, 0.07％, 0.14％, 0.21％, 0.28％, 0.35％), a comparative experiment was conducted using Nanjing 9108 and Yongyou 2640 as materials. Key findings of this study were the following: (1) Saline stress affected the growth and development of rice. Plant height, leaf area and dry matter weight were decreased with the increase of salt concentration. The yield of rice decreased with the increase of salt concentration. When the salt concentration was higher than 0.07％, the yields were significantly lower compared with the control. Yields of Nanjing 9108 were respectively dropped by 14.14％, 43.05％, 58.91％, 65.68％and Yongyou 2640 were dropped by 20.25％, 31.97％, 40.41％, 49.82％.(2)With the increase of salt concentration, the activities of superoxide dismutase(SOD), peroxidase(POD) and catalase (CAT)of the leaves of two varieties showed a trend of rise first then fall, and the highest value was given at the level of 0.07％. (3)During heading stage, free proline content in leaves increased with the increase of salt concentration. When the salt con-centration was higher than 0.14％, the free proline content increased significantly compared with the control. (4)Under saline stress, rice seedling absorbed Na+from roots and discharged K+. With the increase of salt concentration, the K+concentration in different or-gans decreased and the Na+concentration increased, in addition to the K+concentration in the leaves. K+/Na+ratio of different parts showed downward trend. S K、Na between stem and leaves increased with the increase of salt concentration. The stem selectively trans-ported K+ and inhibited Na+ into the leaves. SK、N between root and stem decreased with the increase of salt concentration, The stem absorbed Na+and outputted K+to the root. Overall, low salt concentration had no significant effect on the yield and physiological char-acteristics of high yielding rice varieties, once the salt concentration is higher than 0.07％, the effect was significant.