PEG-6000模拟干旱对水稻苗期根系形态和部分生理指标影响的研究

Study on Effect of Drought Stress with PEG-6000 on Root Morphology and Some Physiological Indices in Rice Seedling

随着全球气候变化,干旱对农作物的产量的影响越来越大,植物地上部分对干旱逆境的响应的研究较多,地下根系在干旱逆境时的变化研究较少,笔者研究了不同PEG浓度处理对2个不同抗逆性的水稻品种根体积、根粗、最长根长3个形态指标和SOD活性、MDA含量、Pro含量、根系活力4个生理指标的影响。结果如下:耐旱品种和敏感品种根部的形态指标都受严重干旱(T3处理)抑制,敏感品种更为明显;形态指标在T0、T1、T2、T3处理下随着处理时间的增加而增大,不同浓度处理之间一般处理3～4天后才会产生明显差异;CAT活性和SOD活性随处理浓度增加而增大,随处理时间延长,抗旱品种SOD的活性增加的速度快于敏感的品种,下降的速度慢于敏感品种;MDA含量和Pro含量随着处理浓度升高而增加,随处理时间增加而增大,敏感品种高于耐旱品种,作为抗旱选择指标并不合适,作为胁迫敏感指标更合适;根系活力随处理时间增加而增大,其最适的处理浓度为T1;相关分析表明根系活力与形态指标正相关极显著,根粗、CAT活性和SOD活性与MDA含量和Pro含量负相关显著或极显著,MDA含量和Pro为极显著的正相关关系,CAT活性和SOD活性也为极显著的正相关关系。

With the change of climate, more and more effect of drought stress on plant production. Two different drought resistant varieties had been treated by PEG-6000 grades （T0, T1, T2 and T3） in rice seedling. Their morphology and physiological indices were surveyed and concluded as followed： The morphology indices of 2 varieties were restrained by strictness drought （T3 treatment） and the sensitive one was more effective than the resistant one. The morphology indiced augment with treatment time prolonging by all PEG-6000 grades and their difference appeared after 3-4 days. CAT and SOD activity augmented with treatment time prolonging and PEG-6000 concentration increasing. The resistant one augments faster than the sensitive one and descends slower than the sensitive variety. MDA and Pro content augmented with treatment time prolonging and PEG-6000 concentration increasing. The effect of the sensitive variety was stronger than the resistant one. So they were not adapted to be drought resistant indices. Root activity augmented with treatment time prolonging.The consistent with or coincide with or et al optimum treatment was T~. Correlation analysis showed that there were very significantly positive correlations between root activity and morphology indices, and significantly or very significantly negative correlations between root diameter, CAT activity, SOD activity and MDA content, praline content. MDA content was very significantly positively related to praline content, CAT activity was very significantly positive correlation to SOD activity.