PSII performance obtained by JIP-text in detached leaf segments during senescence.

<p>The maximum quantum yield of PSII (Fv/Fm) (A), the efficiency of electron move beyond Q_A⁻ (ETo/TRo, B), the absorption flux per CS (ABS/CSo, C), the density of Q_A⁻ reducing PSII reaction centers (RC/CSo, D), quantum yield for electron transport further than Q_A⁻ (ETo/ABS, E) and normalized relative variable fluorescence at the K step (W_K, F) in leaf segments from the two inbred lines of maize (Q319 and HZ4) treated with 0.7 mmol L⁻¹ ethephon or water for different days. The means±SE of six replicates are presented. Different letters indicate significant differences between the parameters in different days after ethephon treatments, P<0.05. The differences was analyzed by LSD (least significant difference).