Table 2 Experimental and coded levels used in central composite design for studying the effects of protoplast concentration (x1), total plasmid DNA (X2), and endosperm age (x3) on protoplast transfection efficiency along with the predicted mean and observed responses
From: Optimization of isolation and transfection conditions of maize endosperm protoplasts
Experimental factor | Coded symbol | Coded variable levels | ||||||
|---|---|---|---|---|---|---|---|---|
Lowest | Low | Centre | High | Highest | ||||
-α (−1.68) | −1 | 0 | +1 | +α (+1.68) | ||||
Protoplast Conc. (× 106) cells/ml | X1 | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 | ||
Total plasmid DNA (µg) | X2 | 5 | 7 | 10 | 13 | 15 | ||
Endosperm age (DAP) | X3 | 6 | 7 | 8 | 9 | 10 | ||
Test number | Coded levels | Actual levels | Response | |||||
|---|---|---|---|---|---|---|---|---|
Transfection efficiency, Y1 (%) | ||||||||
X1 | X2 | X3 | X1 | X2 | X3 | Observed Y1 | Predicted Y1 | |
Coded levels for the three factors selected for protoplast transfection | ||||||||
1 | +1 | +1 | +1 | 2 | 13 | 9 | 35.0 | 35.1 |
2 | +1 | +1 | −1 | 2 | 13 | 7 | 44.6 | 43.2 |
3 | +1 | −1 | +1 | 2 | 7 | 9 | 38.3 | 37.1 |
4 | +1 | −1 | −1 | 2 | 7 | 7 | 34.3 | 36.9 |
5 | −1 | +1 | +1 | 1 | 13 | 9 | 30.6 | 31.3 |
6 | −1 | +1 | −1 | 1 | 13 | 7 | 37.4 | 41.5 |
7 | −1 | −1 | +1 | 1 | 7 | 9 | 27.7 | 33.5 |
8 | −1 | −1 | −1 | 1 | 7 | 7 | 31.5 | 34.9 |
9 | +1.68 | 0 | 0 | 2.5 | 10 | 8 | 43.8 | 45.2 |
10 | −1.68 | 0 | 0 | 0.5 | 10 | 8 | 46.4 | 41.3 |
11 | 0 | +1.68 | 0 | 1.5 | 15 | 8 | 43.5 | 43.0 |
12 | 0 | −1.68 | 0 | 1.5 | 5 | 8 | 42.9 | 39.4 |
13 | 0 | 0 | +1.68 | 1.5 | 10 | 10 | 28.1 | 26.6 |
14 | 0 | 0 | −1.68 | 1.5 | 10 | 6 | 39.6 | 36.3 |
15 | 0 | 0 | 0 | 1.5 | 10 | 8 | 64.3 | 64.8 |
16 | 0 | 0 | 0 | 1.5 | 10 | 8 | 63.3 | 64.8 |
17 | 0 | 0 | 0 | 1.5 | 10 | 8 | 68.4 | 64.8 |
18 | 0 | 0 | 0 | 1.5 | 10 | 8 | 66.2 | 64.8 |
19 | 0 | 0 | 0 | 1.5 | 10 | 8 | 64.4 | 64.8 |
20 | 0 | 0 | 0 | 1.5 | 10 | 8 | 65.1 | 64.8 |
21 | 0 | 0 | 0 | 1.5 | 10 | 8 | 64.2 | 64.8 |
22 | 0 | 0 | 0 | 1.5 | 10 | 8 | 59.6 | 64.8 |
23 | 0 | 0 | 0 | 1.5 | 10 | 8 | 66.7 | 64.8 |