Table 1. Variance components (%) of morphological, yield-related and physiological traits in the context of 101 wheat cultivars × three timings (developmental phase) × three durations of heat stress using the general linear model.
| Traits | Genotype (G) |
Dev. phase (D) | Duration of heat (H) | G×D | G×H | D×H | G×D×H | Residual |
|---|---|---|---|---|---|---|---|---|
| PH | 81.9*** | 3.2 | 1.4 | 7.4*** | 0.1 | 1.2 | 3.1*** | 1.8* |
| LIN | 53.1*** | 16.1* | 4.7 | 8.6*** | 0.5* | 4.4 | 5.0*** | 7.5*** |
| EaL | 74.1*** | 6.7 | 0.1 | 6.3*** | 0.6** | 0.0 | 1.8 | 10.3*** |
| SPIK | 75.7*** | 0.5 | 0.0 | 11.5*** | 0.3* | 0.0 | 3.5*** | 8.4*** |
| DENS | 66.7*** | 9.5 | 0.0 | 10.8*** | 0.3 | 0.0 | 3.2*** | 9.5*** |
| MEaW | 26.4*** | 9.1 | 28.8* | 10.3*** | 1.9*** | 0.2 | 3.3*** | 19.9*** |
| MSW | 20.9*** | 7.7 | 34.3* | 11.0*** | 2.3*** | 0.4 | 3.6*** | 19.8*** |
| MSN | 30.7*** | 0.1 | 13.4 | 21.7*** | 2.3*** | 4.4 | 8.2*** | 19.3*** |
| SPS | 21.8*** | 0.0 | 15.9 | 23.7*** | 2.1*** | 4.4 | 8.8*** | 23.3*** |
| MTKW | 19.3*** | 18.9* | 16.1 | 6.8*** | 1.3*** | 10.6* | 8.0*** | 19.0*** |
| RT | 28.2*** | 18.7* | 2.5 | 13.3*** | 4.0*** | 8.1* | 7.5*** | 17.8*** |
| SEAW | 22.3*** | 3.4 | 40.1** | 2.3*** | 5.6*** | 8.5 | 4.9*** | 12.9*** |
| SSW | 19.7*** | 3.3 | 45.7** | 2.7*** | 6.0*** | 5.9 | 3.5*** | 13.2*** |
| SSN | 20.9*** | 7.8 | 37.2* | 4.0*** | 4.4*** | 5.8 | 4.0*** | 16.0*** |
| BIOM | 40.8*** | 9.4 | 8.5 | 19.4*** | 0.9*** | 4.5 | 8.5*** | 7.9*** |
| GY | 20.2*** | 3.1 | 51.6*** | 2.2*** | 4.7*** | 4.2 | 2.8** | 11.2*** |
| FBIOM | 32.5*** | 4.4 | 30.8* | 7.3*** | 2.5*** | 5.3 | 5.2*** | 11.9*** |
| HI | 14.6*** | 7.9 | 27.8* | 16.8*** | 4.2*** | 0.5 | 4.8*** | 23.4*** |
| AS | 31.3*** | 2.0 | 38.6* | 4.8*** | 3.7*** | 2.7 | 2.8*** | 14.2*** |
| ASW | 27.8*** | 0.1 | 48.8*** | 5.1*** | 4.7*** | 0.8 | 1.6 | 11.2*** |
| ATKW | 29.1*** | 12.4* | 12.9 | 10.6*** | 3.7*** | 5.7 | 5.8*** | 19.8*** |
| EVP | 6.2*** | 8.4 | 32.9* | 8.7*** | 10.4*** | 4.0 | 2.9** | 26.5*** |
| GS | 4.5*** | 1.7 | 66.0*** | 2.3*** | 11.5*** | 1.2 | 1.5 | 11.2*** |
| PN | 0.7* | 0.6 | 89.4*** | 0 | 2.1*** | 0.3 | 1.0 | 5.8*** |
| ICO | 12.9*** | 2.4 | 0.2 | 11.9*** | 22.7*** | 1.7 | 2.1* | 46.1*** |
| CLR | 36.5*** | 12.5* | 13.8 | 7.9*** | 2.3*** | 4.6 | 4.7*** | 17.8*** |
PH—Plant height, LIN—Last internode length, EaL—Main ear length, SPIK—Spikelet number per main ear, DENS—Spike density (spikelet number/cm), MEaW—Main ear weight, MSW—Main seed weight, MSN—Main seed number, SPS—Grain number per spikelet, MTKW—Main thousand- kernel weight, RT—Reproductive tillers, SEAW—Side ear weight, SSW—Side seed weight, SSN—Side seed number, BIOM—Straw biomass, GY—Grain yield, FBIOM—Total aboveground biomass (straw + all ears), HI—Harvest index, AS—Average seed number, ASW—Average seed weight, ATKW—Average thousand kernel weight, EVP–Evaporation, GS—Stomatal conductance, PN—Net assimilation, ICO—Intercellular CO2 concentration, CLR—Chlorophyll content
***, **, and * indicate differences significant at the 0.1%, 1% and 5% probability levels, respectively