Table 2.
Gas exchange and chlorophyll fluorescence parameters in female and male P. cathayana cuttings as affected by solar UV-B radiation.
Treatment | Pn(μmol m−2 s−1) | gs(mol m−2 s−1) | Ci(μmol mol−1) | E (mmol m−2 s−1) | Yield | qP | qN | Fv/Fm |
---|---|---|---|---|---|---|---|---|
MC | 19.55 ± 0.42b | 0.64 ± 0.04b | 314.40 ± 5.10b | 6.32 ± 0.05b | 0.70 ± 0.01ab | 0.96 ± 0.00b | 0.42 ± 0.03a | 0.84 ± 0.00c |
FC | 18.46 ± 0.61b | 0.53 ± 0.03b | 302.11 ± 3.13b | 6.00 ± 0.08b | 0.69 ± 0.03ab | 0.92 ± 0.02b | 0.30 ± 0.07a | 0.82 ± 0.01ab |
MU | 17.72 ± 0.81ab | 0.64 ± 0.02b | 308.36 ± 1.28b | 6.19 ± 0.13b | 0.74 ± 0.01b | 0.96 ± 0.00b | 0.27 ± 0.05a | 0.83 ± 0.00bc |
FU | 15.51 ± 0.24a | 0.34 ± 0.04a | 283.02 ± 7.08a | 4.93 ± 0.28a | 0.62 ± 0.04a | 0.84 ± 0.04a | 0.26 ± 0.05a | 0.81 ± 0.00a |
F: sex | 0.000 | 0.012 | 0.182 | 0.002 | 0.010 | 0.000 | 0.230 | 0.000 |
F: uvb | 0.332 | 0.010 | 0.016 | 0.010 | 0.610 | 0.046 | 0.092 | 0.007 |
F: sex × uvb | 0.009 | 0.000 | 0.001 | 0.000 | 0.024 | 0.028 | 0.354 | 0.427 |
Each value is the mean ± SE (n = 5). MC, males under low UV-B radiation; MU, males under high UV-B radiation; FC, females under low UV-B radiation; FU, females under high UV-B radiation; Fsex, sex effect; F uvb, UV-B effect; Fsex×uvb, the interactive effect of sex and UV-B. Within a column, values followed by different letters are significantly different at P < 0.05 according to Tukey's test. Pn, the net photosynthesis rate; gs, stomatal conductance; Ci, intercellular CO2 concentration; E, transpiration rate; Yield, the effective quantum yield of PSII; qP, photochemical quenching coefficient; qN, non-photochemical quenching coefficient; Fv/Fm, maximum efficiency of PSII.