Table 2.
Maximum pollen germination percentage, modified bilinear equation constants, and cardinal temperatures for pollen germination of 12 cotton cultivars in response to temperature
| Equation constants |
Cardinal temperatures (°C) |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cultivar |
Maximum pollen germination (%) |
a |
b1 |
b2 |
R2 |
Tmin |
Topt |
Tmax |
|||||
| DP 458 B/RR | 59·8 | 66·0 | −0·11 | −4·36 | 83·5 | 15·5 | 31·1 | 45·8 | |||||
| STV 825 | 52·8 | 53·4 | 0·09 | −3·36 | 85·0 | 14·3 | 29·8 | 46·2 | |||||
| FM 832 B | 49·8 | 50·4 | −0·06 | −3·70 | 85·5 | 15·8 | 29·6 | 43·0 | |||||
| NuCOTN 33 B | 46·8 | 50·4 | 0·10 | −3·57 | 79·6 | 14·9 | 28·7 | 43·2 | |||||
| ST 4892 BR | 45·9 | 48·7 | −3·35 | −5·58 | 96·0 | 13·6 | 35·4 | 40·8 | |||||
| Acala 1517–99 | 45·5 | 51·0 | −1·87 | −4·61 | 89·6 | 15·5 | 34·2 | 42·0 | |||||
| DP 5415 RR | 44·3 | 56·6 | −1·40 | −4·52 | 89·9 | 14·7 | 32·9 | 42·4 | |||||
| FM 832 | 42·5 | 44·7 | 0·25 | −3·20 | 79·7 | 16·0 | 28·9 | 44·0 | |||||
| ST 4793 R | 36·4 | 38·3 | 0·25 | −2·58 | 94·2 | 14·8 | 28·4 | 44·8 | |||||
| ST 457 | 35·6 | 41·8 | −1·48 | −3·56 | 90·4 | 20·2 | 33·8 | 44·1 | |||||
| BXN 49B | 35·5 | 42·7 | −1·46 | −3·47 | 89·6 | 11·1 | 32·3 | 41·0 | |||||
| NuCOTN 35 B | 33·0 | 38·2 | −0·68 | −2·84 | 97·7 | 14·3 | 31·9 | 42·7 | |||||
| Mean | 43·99 | – | – | – | 88·4 | 15·1 | 31·4 | 43·3 | |||||
| s.e.d. | 4·03*** | – | – | – | – | 0·20*** | 0·38*** | 0·16*** | |||||
***
Significant at P = 0·001 level.
–, Data not analysed statistically.