水分和高温复合胁迫对水稻幼苗光合生理特性的影响

Effects of Water Stress and High Temperature on Photosynthetic Physiological Characteristics of Rice Seedlings

以水稻"辽星1号"幼苗为材料,进行水分(PEG6000浓度分别为0%、10%、15%、20%)和高温(35、40℃)双重胁迫处理,研究水分和高温复合胁迫对水稻幼苗光合生理特性的影响,为探索调控植物光合生理措施、规避高温干旱复合逆境伤害提供理论依据。结果表明,轻度水分胁迫(PEG6000浓度为10%)下,35℃高温处理的水稻幼苗净光合速率(Pn)、气孔导度(gs)、胞间CO2浓度(Ci)、总叶绿素(Chla+b)含量、叶绿素a/b(Chla/b)、初始荧光产量(Fo)、最大荧光产量(Fm)和PSⅡ最大光化学量子产量(Fv/Fm)与对照相比无显著变化;40℃高温处理的水稻幼苗在3种水分胁迫下,Pn、gs、Ci、Chla+b、Chla/b、Fm和Fv/Fm显著低于对照,Fo显著高于对照。说明35℃高温处理水稻幼苗光合生理特性在轻度水分胁迫下未受到明显抑制,表现出对水分胁迫具有一定的适应性;随着胁迫温度的升高,40℃高温处理的水稻幼苗对水分胁迫的适应性显著下降,其光合生理特性受到明显抑制。

Abstract Rice seedings of ＂ Liao Xing No. 1＂ were used as material, to be treated for water stress （ PEG6000 concentration of 0%, 10%, 15% ,20% ） and high temperature （35℃ and 40℃ ） double stress processing,research to study the effect of water stress and high temperature on photosynthetic physiological characteristics of rice seedlings, and provide theory theoretical basis for exploring the regulation of plant photosynthetic physiological measures and avoiding high temperature and drought composite stress damages characteristics. Results showed that under mild water stress （PEG6000 concentration of 10% ） , for 35℃ high temperature processing of rice seedlings, net photosynthetic rate （ Pn）, stomatal conductance （ gs ）, intercellular CO2 concentration （ Ci ）, total chlorophyll （ Chla ＋ b） content, chlorophyll a/b （ Chla/b）, initial fluorescence yield （ Fo ）, the maximum fluorescence yield （ Fm ） and PS Ⅱ maximum quantum yield of photochemical reaction （Fv/Fm） were not significantly changes compared with the control ;40℃ high temperature processing of rice seedlings under three different degrees of water stress, Pn, gs, Ci, Chla ＋ b, Chla/b, Fm and Fv/Fm were significantly lower than control temperature processing, Fo is higher than control temperature treatment, showing that the rice was not obviously inhibited under mild water stress at 35℃ high seedling significantly photosynthetic physiological characteristics temperature treatment and the adaptability of water stress in to a certain degree. With the increase of temperature stress, the adaptability of rice seedlings to water stress at 40℃ high temperature processing significantly decreased, and the photosynthetic physiological characteristics of rice seedlings was significantly inhibited.