Table 2.

The effects of Cd and IBA on the root and stele diameter, and the cortex thickness of maize (Zea mays L.). The cross section of primary roots was made at the distances of 30%, 60%, and 90% from the root apex. Different letters denote statistically significant differences in the parameters between the treatments at p < 0.05 according to the Tukey test

	Root diameter [μm]
	30%	60%	90%
Control	524.5 ± 22.9a	654.3 ± 15.6b	943.0 ± 5.9b
IBA	511.9 ± 30.8a	632.5 ± 35.4b	1096.8 ± 10.2a
Cd	549.8 ± 22.1a	732.2 ± 0.6a	930.8 ± 47.0b
Cd + IBA	526.8 ± 10.5a	619.8 ± 22.0b	924.3 ± 30.6b
	Stele diameter [μm]
	30%	60%	90%
Control	180.5 ± 11.8c	239.0 ± 5.1b	448.0 ± 5.3a
IBA	219.3 ± 10.8b	262.3 ± 28.1b	424.6 ± 17.5ab
Cd	261.6 ± 6.3a	345.1 ± 3.3a	399.6 ± 23.1b
Cd + IBA	228.2 ± 6.5b	255.9 ± 10.1b	459.2 ± 15.9a
	Thickness of cortex [μm]
	30%	60%	90%
Control	145.3 ± 6.6a	202.7 ± 6.6a	252.0 ± 8.0b
IBA	147.2 ± 6.3a	200.1 ± 21.7a	291.6 ± 4.2a
Cd	157.4 ± 12.1a	182.6 ± 1.3a	204.5 ± 11.4c
Cd + IBA	151.5 ± 5.1a	178.2 ± 8.2a	229.5 ± 11.5bc

Different lowercase letters (a–c) denote statistically significant differences in the parameters between the treatments at p < 0.05 according to the Tukey