Effect of different LED-lighting quality conditions on growth and photosynthetic characteristics of saffron plants (Crocus sativus L.)

Abstract

Abbreviations: B -blue light; Ci -intercellular CO2 concentration; DI0/RC -dissipated energy flux per reaction center; E -transpiration rate; ET0/RC -electron transport flux from QA to QB; Fm -the maximum fluorescence in the OJIP curve; Fo -the minimum fluorescence in the OJIP curve; gs -stomatal conductance; M0 -the initial slope from 0.02 ms to 300 ms in a linear time scale; OEC -oxygenevolving complex; PItotal -performance index for the conservation of energy from photons absorbed by the PSII antenna to the reduction of PSI acceptors; PN -net photosynthetic rate; PQ -plastoquinone; QA -primary quinone acceptor of PSII; QA --reduced primary quinone acceptor of PSII; QA + -oxidized primary quinone acceptor of PSII; QB -secondary quinone acceptor of PSII; R -red light; RC -reaction center; RC/CSm -reaction centers per CS (t = m); VI -normalized variable fluorescence at 30 ms (I point); VJ -normalized variable fluorescence at 2 ms (J point); VPD -vapor pressure deficit; Vt -normalized variable fluorescence at time t; WUE -wateruse efficiency; δRo -efficiency with which an electron from QB is transferred until PSI acceptors; φEo -quantum yield of the electron transport flux from QA to QB; φPo -maximum quantum yield of primary photochemistry; φRo -quantum yield of the electron transport flux until the PSI electron acceptors; ψEo -electron transport efficiency from QAto the PSI electron end acceptors; ψRo -electron transport efficiency except QA.

High-nitrogen fertilizer alleviated adverse effects of drought stress on the growth and photosynthetic characteristics of Hosta ‘Guacamole’

“…To further understand the effect of drought stress on photosynthesis in Hosta ‘Guacamole’, the measurement and analysis of fast chlorophyll a fluorescence is a useful and efficient method for the assessment of many external or intrinsic adverse effects on PS II photochemistry [ 29 ]. In OJIP curve, the positive ΔL-, ΔK-, ΔJ-, and ΔI-bands appeared in T3, indicating that drought stress perhaps resulted in uncoupling of the OEC, accumulation of Q A − , or destroying the acceptor side of PS II [ 26 ].…”

“…The relative fluorescence parameters were calculated by double normalization of the moment chlorophyll fluorescence values to the end point within different intervals with the OJIP part of the transient-OP, OK, OJ, and OI. Following formulae were used for the calculations to clarify the structure and function of the photosynthetic apparatus by describing the primary photosynthetic reactions in PS II [ 29 , 39 ]. The fluorescence parameters are listed in Table 3 .…”