Genetic improvement of yield shapes the temporal and spatial root morphology of soybean (Glycine max) grown in north-east China

Figures & data

Fig. 1  Root growth rate in high- and low-yielding soybean pools across all growth stages. Note: * indicates growth stages at which the root growth rates of the two yielding pools were significantly different at P < 0.05; bars represent standard error of the mean (n = 4)

Fig. 2  Root biomass (A) and root-to-shoot ratio (B) in high- and low-yielding soybean pools across all growth stages. Note: * and ** indicate growth stages at which root biomasses or root-to-shoot ratios of the two yielding pools were significantly different at P < 0.05 and P < 0.01, respectively; bars represent standard error of the mean (n = 4)

Fig. 3  Root length (A) and average root diameter (B) in high- and low-yielding soybean pools across all growth stages. Note: * and ** indicate growth stages at which root lengths or root diameters of the two yielding pools were significantly different at P < 0.05 and P < 0.01, respectively; bars represent standard error of the mean (n = 4)

Table 1  Root length among seven root-diameter classes in real value and percentage distribution for two yielding soybean pools at the R6 stage

	Root length (mm)			Percentage
Diameter classes (mm)	High-yielding	Low-yielding	t- test	High-yielding	Low-yielding	t-test
0.0–0.5	5178±287^a	4332±197	**	72.0±5.3	73.9±4.1	n.s.
0.5–1.0	1262±117	958±212	*	17.5±1.5	16.3±1.9	n.s.
1.0–1.5	390±45.6	295±46.1	*	5.4±0.61	5.0±0.64	n.s.
1.5–2.0	165±21.6	126±22.1	n.s.	2.2±0.22	2.1±0.24	n.s.
2.0–2.5	79±9.7	58±11.7	n.s.	1.1±0.11	1.0±0.14	n.s.
2.5–3.0	42±4.6	33±6.3	n.s.	0.6±0.05	0.6±0.09	n.s.
>3.0	78±3.5	56±9.7	n.s.	1. 1±0.01	1.0±0.11	n.s.
*significance at P < 0.05
**significance at P < 0.01
n.s. no significance
^a±standard error of the mean (n = 4)

Fig. 4  Relationship between root length duration (RLD) and leaf area duration (LAD) in high (A) and low (B)-yielding soybean pools. Note: ** indicates a linear correlation coefficient significant at P < 0.05

Fig. 5  Root biomass density in high- and low-yielding soybean pools along soil profiles, for each of following positions: on plant (A); at halfway between plants (B); at halfway between rows (C). Note: *, ** and *** indicate depths at which root biomass densities of the two yielding pools were significantly different at P < 0.05, P < 0.01 and P < 0.001, respectively; bars represent standard error of the mean (n = 4)

Fig. 6  Root length density in high- and low-yielding soybean pools along soil profiles, for each of following positions: on plant (A); at halfway between plants (B); at halfway between rows (C). Note: * and ** indicate depths at which root densities of the two yielding pools were significantly different at P < 0.05 and P < 0.01, respectively; bars represent standard error of the mean (n = 4)

Fig. 7  Average root diameter in high- and low-yielding soybean pools along soil profiles, for each of following positions: on plant (A); at halfway between plants (B); at halfway between rows (C). Note: * and ** indicate depths at which average root diameters of the two yielding pools were significantly different at P < 0.05 and P < 0.01, respectively; bars represent standard error of the mean (n = 4)

Fig. 8  Root-to-soil volume ratio in high- and low-yielding soybean pools along soil profiles, for each of following positions: on plant (A); at halfway between plants (B); at halfway between rows (C). Note: * and *** indicates depths at which root-to-soil volume ratios of the two yielding pools were significantly different at P < 0.05 and P < 0.001, respectively; bars represent standard error of the mean (n = 4)

Fig. 9  A diagram describing the characteristics of root morphology of high-yielding soybean in the north-east of China