Table 7. Changes in gas exchange parameter of wild and soybean leaves under control and salt stress conditions.

The values are shown as mean ± SE. Different letters (A–G and a–g) mark significantly different values at P < 0.05 according to Duncan’s method. W, wild soybean; C, cultivated soybean; CK, Control; L-NS, M-NS, and H-NS represent low (10 mmol L⁻¹), medium (20 mmol L⁻¹) and high (30 mmol L⁻¹) concentrations of saline salt stress, respectively; while L-AS, M-AS and H-AS represent low (10 mmol L⁻¹), medium (20 mmol L⁻¹) and high (30 mmol L⁻¹) concentrations of alkaline salt stress, respectively.

Variety	Treatment	Pn (CO2m−2 s−1)	Gs (mol m−2 s−1)	E (µmol H2O m−2 s−1)	WUE (Pn/E)	Ci/Ca (cm3m−3)
	CK	12.57 ± 0.24B	1670.33 ± 8.95C	10.33 ± 0.15B	1.22 ± 0.04BC	0.97 ± 0.00A
	L-NS	12.70 ± 0.12B	1680.67 ± 10.59C	11.13 ± 0.12A	1.14 ± 0.01CD	0.91 ± 0.00B
	M-NS	12.73 ± 0.26B	1767.00 ± 28.00B	9.93 ± 0.09B	1.28 ± 0.01B	0.87 ± 0.00C
W soybean	H-NS	13.80 ± 0.10A	1891.33 ± 6.64A	9.10 ± 0.15C	1.52 ± 0.03A	0.83 ± 0.01D
	L-AS	11.43 ± 0.03C	1477.67 ± 8.09D	9.03 ± 0.48C	1.27 ± 0.07B	0.86 ± 0.01C
	M-AS	9.43 ± 0.20D	1398.00 ± 40.38E	8.43 ± 0.12C	1.12 ± 0.03CD	0.83 ± 0.01D
	H-AS	8.27 ± 0.34E	1386.67 ± 5.70E	7.57 ± 0.27D	1.09 ± 0.03D	0.78 ± 0.01E
	CK	11.07 ± 0.03a	1167.33 ± 21.67ab	9.43 ± 0.12a	1.17 ± 0.02a	0.93 ± 0.00a
	L-NS	10.53 ± 0.03a	1199.67 ± 39.83a	9.23 ± 0.09a	1.14 ± 0.01a	0.89 ± 0.03b
	M-NS	9.67 ± 0.07b	1151.67 ± 23.47ab	8.53 ± 0.15ab	1.13 ± 0.01a	0.79 ± 0.00d
C soybean	H-NS	6.83 ± 0.03d	793.33 ± 3.28bc	7.07 ± 0.09b	0.97 ± 0.02a	0.68 ± 0.00f
	L-AS	8.43 ± 0.9c	1132.33 ± 7.88ab	8.07 ± 0.09ab	1.05 ± 0.00a	0.84 ± 0.00c
	M-AS	7.93 ± 0.29c	871.67 ± 105.73abc	7.30 ± 1.30b	1.18 ± 0.26a	0.75 ± 0.01e
	H-AS	5.13 ± 0.42e	609.67 ± 29.18c	5.50 ± 0.17c	0.94 ± 0.09a	0.63 ± 0.00g