【摘要】 研究了不同浓度甲基紫精(MV)对水稻幼苗进行浸根处理,对不同耐冷品种常温和低温下叶绿素荧光参数的影响。结果发现,常温下,低浓度短时间的MV处理引起水稻原初光能转换效率(Fv/Fm)、光合电子传递量子效率(ΦPSⅡ)和光化学猝灭系数(qP)较对照增加,高浓度、长时间的MV处理则使各参数下降并低于对照,耐冷品种可以维持较高的非光化学猝灭系数(NPQ)。低温下只有5μmol/L甲基紫精(简称MV5)短时间处理时两品种的Fv/Fm增加,各处理引起ΦPSⅡ和qP下降,低浓度、短时间MV处理时NPQ增加。这说明轻度氧化胁迫可以刺激水稻的光合能力增加,但氧化胁迫会加剧水稻的低温伤害,耐冷品种也可以通过维持较高的线性电子传递速率和热耗散来避免这种过氧化伤害,表现出强的抗冷性。更多还原

【Abstract】 The roots of rice seedlings were treated with different concentrations of Methyl Viologen(MV)solutions,and the effects of different oxidative stress on the chlorophyll fluorescence parameters of different cold-sensitive cultivars at normal and low temperature were studied.The results showed that at normal temperature,Fv/Fm,ΦPSⅡ and qP of rice seedlings were higher,whereas the parameters were lower treated by higher concentration of MV in longer time than that in their controls,and the cultivar with cold-tolerance had higher NPQ.At low temperature,Fv/Fm increased only when treated by MV5 in shorter time,ΦPSⅡ and qP both decreased with all treatments,and NPQ increased with treatments of less concentration MV in shorter time.This suggests that less oxidative stress may promote the photosynthetic capacity of rice,but oxidative stress could prick up the hurt to rice at low temperature,and the cold-tolerant cultivar showed stronger cold-tolerance because it could relieve the excessive oxidative hurt through maintaining higher linear electron transport rate and heat dissipation ability.更多还原