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

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Na F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(150μs)和K点(300μs);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/CSo、ETo/ABS、PIabs、PIcs等明显下降,而DIo/RC、DIo/CSo和DIo/ABS等参数大幅度增加;叶片氟含量与ETo/TRo、REo/ABS、PICS呈负相关,与DIo/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。

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 fertilizedwith NaF three times weekly for 6 weeks. The results showed that O phase in OJIP curve rose a little treated with600 mg L^–1 NaF, and P phase and IP phase decreased obviously, L-step at about 150 μs and K-step at about 300μs appeared. Under F stress, the fluorescence parameters, such as RC/CSo, ETo/ABS, REo/ETo, REo/ABS, PIabs andPIcs decreased in tea leaves, while VJ, VI, DIo/RC, DIo/CSo, DIo/ABS and dissipated energy increased. There werenegative correlations between F content in tea leaves and ETo/TRo, REo/ABS and PICS, but a positive correlationwith DIo/RC. Therefore, the ability of photosynthetic electron transfer in tea leaves was weakened under Fstress, the whole electron transport chain from PSII to PSI was affected, meanwhile, leaves could prevent lightsuppression and light damage by increasing heat dissipation itself.