Table 4.
Correlation coefficients between root and yield traits in three wheat cultivars (CW134, CH58, and CH1) under moderate drought stress (MD) and well-watered conditions (WW; 2015 Rhizobox experiment), or under rainfed (RF) and irrigated (IR) conditions (2016 Field trial).
| Treatments | Grain yield | Spike number | No. of grains | TKW | HI | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2015 Rhizobox experiment | ||||||||||||
| Root mass | Topsoil root | MD | -0.82** | 0.44 | 0.16 | 0.01 | 0.05 | |||||
| WW | -0.97** | 0.90** | -0.24 | -0.11 | 0.56 | |||||||
| Subsoil root | MD | 0.92** | 0.23 | 0.77* | 0.83** | 0.91** | ||||||
| WW | 0.25 | -0.96** | 0.48 | 0.16 | -0.42 | |||||||
| RLD | Topsoil root | MD | -0.56 | 0.39 | 0.72* | 0.36 | 0.54 | |||||
| WW | -0.75* | 0.91** | -0.70* | -0.31 | 0.48 | |||||||
| Subsoil root | MD | 0.82** | -0.25 | 0.35 | 0.44 | 0.49 | ||||||
| WW | 0.95** | -0.84** | 0.10 | 0.02 | -0.78* | |||||||
| 2016 Field trial | ||||||||||||
| Root mass | Topsoil root | RF | -0.87** | -0.02 | -0.51 | -0.76* | 0.15 | |||||
| IR | -0.60 | -0.64 | -0.47 | -0.51 | -0.52 | |||||||
| Subsoil root | RF | 0.78* | -0.42 | 0.39 | 0.92** | 0.03 | ||||||
| IR | 0.24 | 0.21 | -0.09 | 0.52 | -0.08 | |||||||
| RLD | Topsoil root | RF | -0.85** | -0.14 | -0.76* | -0.48 | 0.17 | |||||
| IR | -0.84** | -0.88** | -0.72* | -0.63 | -0.72* | |||||||
| Subsoil root | RF | 0.75* | -0.64 | 0.34 | 0.90** | 0.12 | ||||||
| IR | -0.30 | -0.38 | -0.42 | -0.04 | -0.47 | |||||||
In the rhizobox experiment, root samples were collected in 2015 at maturity while in the field experiment, they were collected in 2016 at anthesis. RLD, root length density. For ANOVA results in each experiment, ∗, ∗∗, Significant at P < 0.05 and 0.01, respectively.