【摘要】 以东北玉簪和紫萼玉簪为材料,研究了干旱胁迫及复水对玉簪干物质量、部分形态指标、叶绿素含量、气体交换和叶绿素荧光参数的影响,结果表明,随干旱胁迫时间的延长和干旱程度的增加,干旱胁迫处理对2种玉簪干物质量、部分形态指标、叶绿素含量的抑制作用逐渐增大。此外,干旱胁迫处理能够降低或显著降低2种玉簪的净光合速率(P n)、气孔导度(G s)、蒸腾速率(T r),降低或升高胞间CO2浓度(C i);降低或显著降低PSII最大光能转化效率(F v/F m)、光适应下PSII最大光能转化效率(F v’/F m’)、PSII电子传递量子效率(ΦPSII)和光化学猝灭系数(qP),显著提高非光化学猝灭系数(NPQ)。而干旱胁迫处理15或30 d后复水15 d,各指标均能得到不同程度的恢复;30d的干旱胁迫未造成光合细胞器的不可逆损伤。2种玉簪相关生理指标的比较分析结果显示,东北玉簪抗旱能力强于紫萼玉簪。更多还原

【Abstract】 The effects of drought stress and re-watering on dry weights,some morphological indicators,chlorophyll content,gas exchange and chlorophyll fluorescence parameters of Hosta were studied using H. clausa var. ensata and H. ventricosa as examples. With time and an increase of drought stress,the effect of drought stress on dry weights,some morphological indicators and chlorophyll content of the two Hostas gradually increased. In addition,the net photosynthetic rate( P n),stomatal conductance( G s),and transpiration rate( T r) decreased or significantly decreased,internal CO 2 concentration( C i) decreased or increased,and the maximum quantum yield of PSII photochemistry( F v / F m),the PSII maximum efficiency within light-adapted material( F v ’ / F m ’),actual efficiency of photochemical energy conversion in PSII under light( Φ PSII),photochemical quenching coefficient( qP) all decreased or significantly decreased,but the nonphotochemical Chl fluorescence quenching( NPQ) of the two Hosta species significantly increased. After drought stress for 15 days or 30 days and re-watering for 15 days,the indicators recovered to differing extents. There was no irreversible damage to the photosynthetic apparatus after drought stress for 30 d. The comparative analysis of related physiological indexes showed that the drought resistance of H. clausa var. ensata was stronger than that of H. ventricosa.更多还原