循环干旱锻炼对在干旱胁迫下烟草植株光合参数及叶绿素荧光参数的影响

[目的]研究循环干旱锻炼对在干旱胁迫下烟草植株叶片光合参数及叶绿素荧光参数的响应差异,从一个侧面了解干旱锻炼提高烟草抗旱性的机制。[方法]通过对漂浮育苗的烟草幼苗进行控水—半萎蔫—复水—恢复的循环干旱锻炼及后续干旱胁迫,测定烟草光合参数及叶绿素荧光参数。[结果]循环干旱锻炼后烟草植株在随后的干旱胁迫下烟叶净光合速率(Pn)、PSⅡ最大光化学量子效率(Fv/Fm)、PSⅡ实际光化学量子效率(ΦPSⅡ)、光化学淬灭系数(qP)比未锻炼的对照高,而非光化学淬灭系数(NPQ)下降。[结论]循环干旱锻炼提高了烟草植株光合系统对干旱胁迫的适应能力。

Effect of Circular Drought Hardening on Photosynthesis and Chlorophyll Fluorescence Parameters of Tobacco(Nicotiana tabacum L.) under Drought Stress

[Objective] To investigate the differential responses of photosynthesis and chlorophyll fluorescence parameters of tobacco(Nicotiana tabacum L) plants with and without circular drought-hardening to drought stress,and to understand the mechanisms of enhancement of drought resistance by the drought-hardening from one profile.[Method] Circular drought-hardening was applied to tobacco seedlings raised on floating trays by water control-half wilting-rehydration-recovery circle and subsequent drought stress,the changes of photosynthesis and chlorophyll fluorescence parameters were measured in tobacco leaves.[Result] The drought-hardened tobacco plants could maintain higher net photosynthetic rate(Pn),optimal quantum yield of ΦPSⅡ(Fv/Fm),actual photochemical efficiency of PSⅡ(ΦPSⅡ),and photochemical quenching(qP),and lower non-photochemical quenching(NPQ) under drought stress as compared with control without the drought-hardening.[Conclusion] The circular drought-hardening enhanced adaptive capacity of photosynthetic system of tobacco plants to drought stress.