不同浓度氟对茶树幼苗叶片叶绿素荧光特性的影响

Effects of Fluoride Stress on Chlorophyll Fluorescence in Leaves of Tea Seedlings

摘要:

为探讨氟对茶树[Camellia sinensis (L.) O. Kuntze]叶片叶绿素荧光特性的影响,采用盆栽沙培法,用不同浓度的NaF 溶液处理6 周,对茶树叶片的叶绿素荧光特性进行研究。结果表明,用600 mg L^-1 的氟处理,茶苗叶片的OJIP 曲线O 相呈小幅度上升,P 相下降得非常明显,IP 相显著下降,出现清晰的L 点(150 μs)和K 点(300 μs);经过氟处理的茶苗叶片I 点、J 点的相对可变荧光和耗散能增加;荧光参数RC/CS_o、ET_o /ABS、PI_abs、PI_cs 等明显下降,而DI_o/RC、DI_o/CS_o 和DI_o/ABS 等参数大幅度增加;叶片氟含量与ET_o/TR_o、RE_o/ABS、PI_CS 呈负相关,与DI_o/RC 呈正相关。因此,氟胁迫处理削弱了茶树叶片的光合电子传递能力,影响了光合机构的作用,同时叶片以增加自身热耗散来防止受到光抑制和光破坏。

Abstract:

The objective was to understand the effect of fluoride (F) stress on chlorophyll fluorescence in tea [Camellia sinensis (L.) O. Kuntze ‘Ruixiang’] leaves. Tea seedlings at 10-month-old grown in pots were fertilized with NaF three times weekly for 6 weeks. The results showed that O phase in OJIP curve rose a little treated with 600 mg L^-1 NaF, and P phase and IP phase decreased obviously, L-step at about 150 μs and K-step at about 300 μs appeared. Under F stress, the fluorescence parameters, such as RC/CS_o, ET_o/ABS, RE_o/ET_o, RE_o/ABS, PI_abs and PI_cs decreased in tea leaves, while V_J, V_I, DI_o/RC, DI_o/CS_o, DI_o/ABS and dissipated energy increased. There were negative correlations between F content in tea leaves and ET_o/TR_o, RE_o/ABS and PI_CS, but a positive correlation with DI_o/RC. Therefore, the ability of photosynthetic electron transfer in tea leaves was weakened under F stress, the whole electron transport chain from PSII to PSI was affected, meanwhile, leaves could prevent light suppression and light damage by increasing heat dissipation itself.