Table 1.
Results of binomial logistic regression analysis of factors affecting likelihood of SRE expression
| Term | Parameter estimate (±SE) | Wald chi-square statistic | df | p | Estimated odds ratio |
|---|---|---|---|---|---|
| Constant |
−2.34 (0.35) |
45.25 |
1 |
0.23 |
- |
| Year = 2008 |
−0.30 (0.20) |
2.27 |
1 |
0.74 |
1.07 |
| Year = 2009 |
0.07 (0.17) |
0.16 |
1 |
1.07 |
0.74 |
| Year = 2010 |
0 |
- |
- |
- |
1.00 |
| Bolting month = June |
2.93 (0.24) |
149.82 |
1 |
< 0.001* |
18.79 |
| Bolting month = July |
2.45 (0.23) |
108.93 |
1 |
<0.001* |
11.61 |
| Bolting month = August |
0.81 (0.24) |
11.49 |
1 |
<0.001* |
2.26 |
| Bolting month = September |
0 |
- |
- |
- |
1.00 |
| Size | 0.02 (0.01) | 3.33 | 1 | 0.07 | 1.02 |
The four bolting groups were experimentally produced using a photoperiod manipulation, and this manipulation was repeated for three years from 2008-10. Prebolting plant size was measured as the length (in mm) of the longest living leaf of the unbolted rosette. The regression model significantly predicts likelihood of SRE expression (χ2 = 274.52, df = 6, p < 0.005). Odds ratios express relative likelihood of SRE expression.
*p < 0.05.