Table 5 Photosynthetic pigments, chlorophyll fluorescence and gas exchange in young Eucalyptus urophylla plants sprayed with EBR and exposed to Ni toxicity
Photosynthetic pigments | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Ni | EBR | Chl a (mg g−1 FM) | Chl b (mg g−1 FM) |  | Total Chl (mg g−1 FM) | Car (mg g−1 FM) | Ratio Chl a/Chl b | Ratio total Chl/Car | |||||
− | − | 9.46b |  | 3.98b |  | 13.44b |  | 0.67b |  | 2.39c |  | 19.9b |  |
− | + | 10.96a | 16% | 4.66a | 17% | 15.63a | 16% | 0.82a | 22% | 2.36c | -1% | 19.2b | − 4% |
+ | − | 7.76c |  | 2.49d |  | 10.25d |  | 0.45d |  | 3.13a |  | 22.6a |  |
+ | + | 8.86b | 14% | 3.17c | 27% | 12.03c | 17% | 0.59c | 31% | 2.80b | − 11% | 20.4b | − 10% |
Chlorophyll fluorescence | |||||||||||||
Ni | EBR | ΦPSII | qP |  | NPQ | ETR (μmol m−2 s−1) |  | EXC (μmol m−2 s−1) | ETR/PN | ||||
− | − | 0.31a |  | 0.84a |  | 0.72c |  | 45.48a |  | 0.62c |  | 2.44a |  |
− | + | 0.32a | 3% | 0.80a | − 5% | 0.69c | − 4% | 47.08a | 4% | 0.62c | 0% | 2.44a | 0% |
+ | − | 0.16c |  | 0.51b |  | 1.12a |  | 23.97c |  | 0.77a |  | 2.60a |  |
+ | + | 0.23b | 44% | 0.53b | 4% | 0.99b | − 12% | 34.08b | 42% | 0.71b | − 8% | 2.54a | − 2% |
Gas exchange | |||||||||||||
Ni | EBR | PN (μmol m−2 s−1) | E (mmol m−2 s−1) | gs (mol m−2 s−1) | Ci (μmol mol−1) | WUE (μmol mmol−1) | PN/Ci (μmol m−2 s−1 Pa−1) | ||||||
− | − | 18.6a |  | 3.32a |  | 0.45a |  | 269c |  | 5.6a |  | 0.072a |  |
− | + | 19.3a | 4% | 3.37a | 2% | 0.45a | 0% | 259c | − 4% | 5.7a | 2% | 0.079a | 10% |
+ | − | 9.2c |  | 2.53c |  | 0.25c |  | 298a |  | 3.6c |  | 0.034c |  |
+ | + | 13.4b | 46% | 2.85b | 13% | 0.31b | 24% | 286b | − 4% | 4.7b | 31% | 0.052b | 53% |