旱涝快速转换对分蘖后期水稻生理特性的影响

采用测筒试验研究了水稻分蘖期旱涝快速转换前后的光合特性和生理活性.结果表明:旱涝快速转换后轻度淹涝处理,叶片的光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Cs)得以逐渐恢复;重度淹涝叶片的Pn,Tr和Cs均显著低于对照,且随时间的推移呈下降趋势.旱后轻涝和旱后重涝处理的叶绿素a、叶绿素b、类胡萝卜素(CAR)的质量分数和叶绿素(a b)的质量分数均低于对照.旱涝快速转换后轻度淹涝处理丙二醛(MDA)的质量摩尔浓度与对照差异不显著,而重度淹涝处理则极显著高于对照.旱后轻涝处理有利于根系活力(TTC还原强度)的提高,表现出超补偿效应,而旱后重涝处理的根系活力则显著降低.

Effects of rapid shift from drought to waterlogging stress on physiological characteristics of rice in late tillering stage

Pot experiments were conducted to study the effects of drought stress and waterlogging stress on photosynthetic and physiological characteristics of rice during the late tillering stage.The results show that the photosynthetic rate(Pn),transpiration rate(Tr) and stomatal conductance(Cs) recover gradually when drought stress is followed by mild waterlogging stress(HQ),but they remain significantly lower under severe waterlogging stress(HZ) than they do under flooding irrigation(CK) and they continue deceasing with time.Under both HQ and HZ treatment,the mass fractions of the chlorophyll(a b),chlorophyll a,chlorophyll b and carotenoid are all lower than they are under CK.The malondialdehyde(MDA) molality shows no significant difference under HQ or CK,but it is significantly higher under HZ treatment.The root activity(TTC-reducing intensity) increases significantly under HQ treatment compared with that under CK,indicating that there is an over-compensation effect,but it decreases significantly under HZ treatment.