Table 4. Pearson correlation coefficient between overall mean of seed germination percentage and rate (mean of four levels of water potential and three replicates), emergence percentage and index and hydrotime parameters (θH, Ψb(50), σφb) at different environmental conditions of control, water stress, salinity stress and field sowing for 10 alfalfa seed lots.
| Variable | θH (MPa•h) | Ψb(50) (MPa) | σ φb | |
|---|---|---|---|---|
| Laboratory | Germination (%) | −0.152 | −0.983 (<0.001) | 0.206 |
| Germination rate (h−1) | -0.641 (0.046) | −0.746 (0.013) | −0.204 | |
| Greenhouse | Control condition | |||
| Emergence (%) | −0.317 | −0.807 (0.005) | 0.086 | |
| Emergence index | −0.136 | −0.841 (0.002) | 0.196 | |
| Water stress | ||||
| Emergence (%) | −0.368 | −0.624 (0.054) | −0.120 | |
| Emergence index | −0.185 | −0.813 (0.004) | −0.011 | |
| Salinity stress | ||||
| Emergence (%) | −0.124 | −0.834 (0.003) | 0.280 | |
| Emergence index | −0.039 | −0.927 (<0.001) | 0.320 | |
| Field | Field experiment | |||
| Emergence (%) | −0.457 | −0.751 (0.012) | −0.043 | |
| Emergence index | −0.424 | −0.728 (0.017) | 0.129 | |
Note:
The θH is constant hydrotime, Ψb(50) is base water potential for 50% of seeds to germinate, σφb is standard deviation of Ψb(50). Numbers in parentheses indicate the significance of the coefficients. Three replications for each treatment of each seed lot.