以玉米自交系郑58(抗旱性强)和丹340(抗旱性弱)为材料,采用盆栽控水试验,设置中度干旱和正常灌水处理,研究了干旱胁迫对玉米自交系苗期、抽雄吐丝期和灌浆期叶片叶绿素荧光指标的影响。结果表明：不同生育时期,玉米自交系叶片光系统II(PS II)的最大荧光(Fm)、原初最大光能利用效率(Fv/Fm)、潜在光化学效率(Fv/F0)、有效光化学量子产量(Fv’/Fm’)、实际光化学量子效率(ΦPSII)和光化学猝灭系数(qP)均随干旱胁迫的加剧而下降,初始荧光(F0)和非光化学猝灭系数(qN)均随干旱胁迫的加剧而升高,且与丹340相比,郑58的Fm、Fv/Fm、Fv/F0、Fv’/Fm’降幅均相对较小。不同时期干旱胁迫下,郑58的Fm、Fv/Fm、Fv/F0、Fv’/Fm’、ΦPSII和qP均高于丹340。这些结果暗示,与丹340相比,干旱胁迫下,郑58光系统II具有较高的光能转化和利用效率、实际光化学量子效率和有效光化学量子产量,通过调节碳同化能力和激发能利用效率,有效地耗散过剩光能减轻光抑制,保护光合机构,维持较高的光合性能是其抗旱的主要生理原因。根据试验结果,光系统II中Fm、Fv/Fm和Fv/F0可以用来鉴定玉米自交系抗旱性。
英文摘要:
Effect of water stress on leaf chlorophyll fluorescence characteristics in maize inbred lines was carried on with Zheng 58(higher drought resistance) and Dan 340(lower drought resistance). This experiment was studied by pot treatment under 2 soil water content ranges (70%-80% and 50%-60%) in green house. Water stress stage was V6, R1 and R3, respectively. The result showed that Fm, Fv/Fm, Fv/F0, Fv’/Fm’,ΦPSII and qP of PSII was decreased, F0 and qN was increased with the water stress increasing. The decreased range of Fm, Fv/Fm, Fv/F0 and Fv’/Fm’ in Zheng 58 was lower than that of in Dan 340. Fm, Fv/Fm, Fv/F0, Fv’/Fm’, ΦPSII and qP of Zheng 58 was higher than that of Dan 340 at 3 water stress stages. The results indicated that main physiological reason of drought resistance is higher conversion and utilization efficiency of light energy, ΦPSII and Fv’/Fm’. And dissipating excess light energy to reduce photoinhibition, protecting the photosynthetic mechanism, maintaining higher photosynthetic performance by adjusting carbon assimilation ability and excitation energy use efficiency. According to this study results, Fm、Fv/Fm and Fv/F0 in PSII could be used to evaluate and identify drought resistance in maize inbred lines.
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