盐胁迫下玉米苗期农艺性状和脯氨酸含量变化的研究

玉米是重要的粮食和饲料作物,但在盐碱地上很难获得高产,盐胁迫是最主要的限制因子。研究玉米在盐胁迫下的性状表现,建立玉米耐盐筛选的技术指标体系,对耐盐机理及分子育种研究有重要意义。本研究采用室内沙培盆栽的方法,对3个不同玉米自交系进行苗期的NaCl梯度胁迫处理,对出苗时间、苗高、地上部鲜重,根系鲜重及游离脯氨酸含量等性状进行考察,分析各性状与盐胁迫处理浓度之间的相关关系。结果表明,3个不同品种中,黄早四和TL94B的耐盐性相对较强,87-1的耐盐性相对较弱;100￣120mM为玉米盐胁迫筛选的下限临界浓度,200￣220mM为玉米盐胁迫筛选的上限临界浓度;出苗时间、苗高、地上部鲜重、根系鲜重、脯氨酸含量等指标与盐浓度的相关性均达到P<0.01的极显著水平,都可作为玉米的耐盐性鉴定的依据;研究还发现,游离脯氨酸含量随盐胁迫浓度升高而升高,但盐浓度超过临界上限后,脯氨酸含量反而下降。

The Changes of Proline Content and Agronomical Traits under Salt Stress in Maize Seedling Stage

Maize is an important food and forage crop, however, it is very difficult to get high yield in saline soil. Salt stress is the uppermost limiting factor. It is very significant to study maize trait performance under salt stress and establish maize salt-tolerant screening system to molecular breeding and understanding salt-tolerance mechanism. In this research, using sand pot-planting method indoors, with three different maize inbred lines stressed by NaCl grads in seedling stage, sprouting time, seedling height, fresh weight of stem and leaf, fresh weight of root, free proline content, and analyzed the correlativity between salt concentration and all traits were investigated. The results were as following: in three maize inbred lines, the salt-tolerance of Huangzaosi and TL94B were higher than that of 87-1 relatively. 100~120mM was the lower limit critical concentration of NaCl in maize salt-tolerant screening, and 200~220mM was the upper limit critical concentration. All the traits investigated in this research, including sprouting time, seedling height, fresh weight of stem and leaf, fresh weight of root, free proline content, were significant correlative to salt concentration at P<0.01 level, and all can be used for identifying index in maize salt-tolerance evaluation. Moreover, free proline content was synchronously rising up with salt concentration, when salt concentration exceeded the critical upper limit, the free proline content declined instead.