Table 3. Chlorophyll a (Chl a), chlorophyll b (Chl b), chlorophyll (a+b) and net photosynthetic rate (Pn) of Sorghum bicolor (L.) Moench seedlings under various salt and alkali stresses.
| Treatment | Salinity (mmol/L) | Chl a (mg·g-1) | Chl b (mg·g-1) | Chl (a+b) (mg·g-1) | Pn (μmol/m2/s) |
|---|---|---|---|---|---|
| CK | 0 | 1.29±0.12ae | 1.75±0.06a | 3.04±0.08a | 14.34±2.61a |
| A1 | 100 | 1.53±0.11ab | 1.14±0.04bcd | 2.67±0.15bcd | 39.93±0.04b |
| A2 | 200 | 1.69±0.06bd | 1.27±0.07b | 2.96±0.13ac | 35.30±0.25c |
| A3 | 300 | 1.38±0.04ace | 1.12±0.01bcd | 2.50±0.04bd | 16.08±0.52a |
| B1 | 100 | 1.59±0.09bc | 1.19±0.06bc | 2.78±0.14abc | 21.12±0.21d |
| B2 | 200 | 1.55±0.10ab | 1.24±0.11bc | 2.80±0.19abc | 15.73±0.37a |
| B3 | 300 | 1.86±0.12d | 1.22±0.03bc | 3.07±0.14a | 0.67±0.67e |
| C1 | 100 | 1.26±0.07e | 1.09±0.03cd | 2.35±0.10d | 4.32±0.03f |
| C2 | 200 | 1.60±0.08bcd | 1.24±0.01b | 2.84±0.08abc | 6.98±0.20g |
| C3 | 300 | 0.93±0.08f | 0.98±0.04d | 1.91±0.12e | 0.12±0.04e |
Note: Values represent means±S.E. Values at each treatment group followed by different letters are significantly different (P < 0.05)