Table 1.
Phenotype category | Phenotype | Calculation | Definition |
---|---|---|---|
Drought score and water relations | |||
DS | Drought scoring system based on the appearance characteristics of seedlings | ||
Drought score | RWC | (fresh weight (FW) – dry weight (DW)) / (turgor weight (TW) – DW) | Leaf relative water content (RWC) |
Gas-exchange parameters | |||
Pn | Net photosynthetic rate (μmol CO2 m−2 s−1) | ||
Tr | Transpiration rate (mmol H2O m−2 s−1) | ||
gs | Stomatal conductance (mol H2O m−2 s−1) | ||
Gas-exchange | Ci | Intercellular CO2 concentration (μmol CO2 mol−1 air) | |
parameters | Ca | Atmospheric CO2 concentration | |
WUEintri | Pn/gs | WUEintri in μmol CO2 mmol H2O−1 | |
WUEinst | Pn/Tr | WUEinst in μmol CO2 mmol H2O−1 | |
CE | Pn/Ci | An estimate of carboxylation efficiency of Rubisco | |
Fluorescence parameters | |||
F0 | F0 = F50μs | Minimum Fluorescence, when all PSII RCs are open | |
FJ | FJ = F2m | Fluorescence intensity at the J-step (2 ms) | |
Primary | FI | FI = F60ms | Fluorescence intensity at the I-step (60 ms) |
fluorescence | FM | FM = F1s | Maximum fluorescence, when all PSII RCs are closed |
measurements | FV | FV = FM - F0 | Variable fluorescence |
VJ | VJ = (FJ-F0)/(FM-F0) | Variable Fluorescence at the J-step | |
VI | VI = (FI-F0)/(FM-F0) | Variable fluorescence at the I-step | |
FM/F0 | |||
Fluorescence ratios | FV/F0 | Maximum efficiency of photochemistry | |
FV/FM | (FM - F0)/FM | Maximum yield of primary photochemistry | |
M0 | 4(F300μs - F0)/(FM - F0) | Rate of reaction center closure | |
N | (Area/(FM - F0)) × M0 × (1/VJ) | Turn-over number QA reduction events between time 0 and FM |
|
Ψ0 | Ψo = ET0/TR0 = 1- VJ | Likelihood that a trapped exciton can move an electron further than QA− |
|
Derived parameters | φEo | ΦEo = ET0/ABS = (1-(F0/FM)) × Ψ | Quantum yield of electron transport to intersystem electron acceptors (between photosystem II and I) |
φDo | ΦDo = 1- Φp0 = (F0/FM) | Quantum yield at time 0 for energy dissipation | |
Φpav | Φpav = Φp0(1-Vav) | Average quantum yield of primary photochemistry | |
PIABS | (RC/ABS) × (φPo/1- φPo) | Performance Index of PSII normalized for equal absorption | |
ABS/RC | ABS/RC = M0 × (1/VJ) × (1/Φp0) | Energy absorption by antenna per reaction center (indicator of antenna size for PSII) |
|
Energy flux parameters |
TR0/RC | TR0/RC = M0 × (1/VJ) | Flux of excitons trapped per reaction center: reduction of Pheophytin and QA |
ET0/RC | ET0/RC = M0 × (1/VJ) × Ψ0 | Energy flux for electron transport per reaction center: beyond QA− | |
DI0/RC | DI0/RC = (ABS/RC)-(TR0/RC) | Flux ratio of energy dissipation per reaction center |