水培番茄侧根对盐胁迫的响应

以番茄品种石头为试材，采用分根水培装置，剪除主根同侧侧根，对番茄根系进行盐胁迫试验。设盐胁迫浓度分别 为0（CK）、0.1%、0.2% 和0.3% 4 个处理，通过测定侧根的根系活力、根系干质量和根系形态参数等指标，研究番茄根系 在盐胁迫下的生长状况和耐盐阈值。结果表明：侧根的生长符合慢- 快-慢的Logistic 生长模型，盐浓度为0.1% 的胁迫推 迟了根系的生育进程，根系活力、根系干质量和根系形态参数均高于对照；盐浓度为0.2% 和0.3% 的胁迫下根系生育进程 均提前，根系干质量和根系形态参数均较对照下降，根系生长受到抑制。当主根受到伤害会激发侧根的生存潜力，进行补偿 生长。根系的形态参数对耐盐性的贡献较大，总根长、根表面积和根体积可作为根系的耐盐指标。综上，对侧根生长有利的 盐胁迫环境为浓度0.1% 的盐溶液，通过Logistic 模型可以预测根系生长的始盛点、高峰点和盛末点，从而采取有效措施对 盐胁迫下侧根的生长进行调控。

Response of Tomato Lateral Root to Salt Stress Under Hydroponic Condition

Taking tomato variety‘stone’as test material，the paper carried out salt stress test on tomato root system by hydroponic device and wiping out main root and lateral root．Four treatments of salt stress concentration were 0（CK），0.1%，0.2% and 0.3%，respectively．The paper studied the growth status and salt tolerance threshold of tomato root system by testing lateral root system activity，dry root weight and root morphological parameters，etc. indexes．The results showed that the growth of lateral roots all accorded with the slow-fast-slow Logistic growth model．Stress with 0.1% salt concentration could delay the development progress of root system．The root system activity，dry root weight and root system morphological parameters were all higher than that of the contrast．Under stress with 0.2% and 0.3% salt concentration，the root system development progress was all ahead of schedule，then the dry root weight and root morphological parameters were all lower than that of the contrast．The growth of root system was inhibited．The injuried main root would stimulate the survival potential of lateral roots conducting compensatory growth．The root morphological parameters had bigger contribution to salt tolerance．Total root length，root superficial area and root volume could be taken as salt tolerance indexes．To sum up，the salt stress environment benificial to lateral root growth is 0.1% salt concentration．The Logistic model can be used to predict the origin，peak and terminal points of root growth，so that effective measures can be taken to regulate the growth of lateral root under salt stress．