Table 1. Effects of Cd on plant biomass, Cd tolerance, and the root/shoot ratio in two cultivars of Italian ryegrass.

Cultivar	Cd supply μM	Plant biomass (mg·plant−1 DW)		TIs		Root/shoot ratio
		R	S	R	S
IdyII	0	22.51 ± 2.77 a	123.98 ± 10.40 a			0.18 ± 0.012 a
	5	22.60 ± 1.94 a	120.19 ± 12.04 a	1.00 ± 0.09 a	0.97 ± 0.10 a	0.19 ± 0.031 a
	10	21.52 ± 2.33 ab	113.92 ± 14.28 a	0.96 ± 0.10 ab	0.92 ± 0.12 ab	0.19 ± 0.005 a
	25	17.54 ± 1.09 bc	103.17 ± 12.63 ab	0.78 ± 0.05 bc	0.83 ± 0.10 abc	0.18 ± 0.036 a
	50	13.30 ± 1.57 cde	80.48 ± 8.41 bcd	0.59 ± 0.07 d	0.65 ± 0.07 c	0.16 ± 0.003 ab
	100	9.26 ± 0.99 ef	78.08 ± 7.86 bcd	0.41 ± 0.04 e	0.63 ± 0.13 cd	0.12 ± 0.014 b
Harukaze	0	15.29 ± 0.99 cd	84.00 ± 5.05 bc			0.18 ± 0.023 a
	5	14.64 ± 0.76 cd	67.99 ± 2.92 cd	0.96 ± 0.05 ab	0.81 ± 0.03 bc	0.22 ± 0.006 a
	10	12.26 ± 0.90 de	63.36 ± 3.64 cd	0.80 ± 0.06 bc	0.75 ± 0.04 bc	0.19 ± 0.011 a
	25	9.69 ± 0.70 ef	55.06 ± 3.74 de	0.63 ± 0.05 cd	0.65 ± 0.04 c	0.18 ± 0.010 a
	50	5.46 ± 0.58 fg	35.20 ± 3.62 ef	0.36 ± 0.04 ef	0.42 ± 0.04 de	0.16 ± 0.017 ab
	100	3.22 ± 0.13 g	29.55 ± 1.43 f	0.21 ± 0.01 f	0.35 ± 0.02 e	0.11 ± 0.007 b
ANOVA (F values)	Cd	153.72**	11.04**	38.32**	11.87**	5.97*
	Cultivar	25.79**	92.04**	15.15**	18.93**	0.017ns
	Cd × cultivar	0.268ns	0.13ns	0.63ns	0.24ns	0.194ns

Notes:

Values (mean ± SE, n = 3) with different letters in the same columns are significantly different according to the Duncan’s multiple range test.

DW, dry weight; TI, tolerance index; R, root; S, shoot.

*P < 0.05, **P < 0.01, ***P < 0.001; ns, not significant.