Table 5.
Mean percentage of spikelet and spikelet weight per spikelet at each position (primary, secondary, tertiary, and quaternary) in the panicles as affected by different CO2 concentrations and genotype averaged for two years (2012 and 2013).
| CO2 concentration | Genotype | Percentage of spikelet | Spikelet weight | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Primary (%) | Secondary (%) | Tertiary (%) | Quaternary (%) | Primary (mg spikelet−1) | Secondary (mg spikelet−1) | Tertiary (mg spikelet−1) | Quaternary (mg spikelet−1) | ||
| CO2 concentration (C) | |||||||||
| FACE | 6.7 | 52.8 | 40.4 | 0.0 | 24.6 | 23.6 | 18.7 | 0.3 | |
| Ambient | 6.9 | 53.6 | 39.6 | 0.0 | 23.9 | 23.3 | 15.5 | 0.0 | |
| Genotype (G) | |||||||||
| Koshihikari | 7.7a† | 57.5a | 34.8b | 0.0 | 24.7a | 24.5a | 19.2a | 0.0 | |
| CSSL-GN1 | 6.2b | 50.5b | 43.3a | 0.0 | 23.6b | 21.9b | 14.3b | 0.0 | |
| NIL-APO1 | 6.6b | 51.5b | 41.9a | 0.1 | 24.5a | 24.0a | 17.8a | 0.5 | |
| C × G | |||||||||
| FACE | Koshihikari | 7.7 | 57.6 | 34.7 | 0.0 | 25.6aA‡ | 25.1 | 21.5 | 0.0 |
| CSSL-GN1 | 6.0 | 49.8 | 44.2 | 0.0 | 23.3b | 21.8 | 15.1 | 0.0 | |
| NIL-APO1 | 6.5 | 51.0 | 42.5 | 0.1 | 24.8a | 24.0 | 19.4 | 1.0 | |
| Ambient | Koshihikari | 7.7 | 57.4 | 34.8 | 0.0 | 23.8B | 23.9 | 16.9 | 0.0 |
| CSSL-GN1 | 6.3 | 51.3 | 42.5 | 0.0 | 23.9 | 22.1 | 13.4 | 0.0 | |
| NIL-APO1 | 6.7 | 52.1 | 41.3 | 0.0 | 24.1 | 24.1 | 16.1 | 0.0 | |
| ANOVA | |||||||||
| CO2 concentration (C) | NS¶ | NS | NS | NS | NS | NS | * | NS | |
| Genotype (G) | ** | ** | ** | NS | §§ | * | * | NS | |
| C × G | NS | NS | NS | NS | § | NS | NS | NS | |
*Significant at P < 0.05. **Significant at P < 0.01. †Means within a column followed by the same lowercase letter do not differ significantly (P < 0.05). ‡Means within a column followed by the same lowercase letter do not differ significantly (P < 0.05) among genotypes for a given CO2 concentration. Means within a column followed by the same uppercase letter do not differ significantly (P < 0.05) between CO2 concentrations for a given genotype. §Significant at P < 0.10. ¶Not significant at P < 0.10.