Table 3. Test for evolutionary forces shaping IFS1, IFS2, F3H2 gene, only CDS were considered.

Gene	Tajima’s D		Ka/Ks
	C	W	C	W
IFS1	−1.38	−2.20**	0.16	0.27
IFS2	−2.39***	−2.22**	0.25	0.56
F3H2	−0.21	0.76	1.19	0.81
Average	−1.33	−1.22
R1
EU450800	−1.39	−1.61	0.68	0.57
L20310	0.14	0.03	5.51	1.82
D13505	−1.28	−1.65	0.10	0.17
Average	−0.84	−1.07
R2
K00821	/	−1.38	0/0	0.33
AF083880	/	−1.16	0/0	1.53e−4/0
AF124148	0.96	−0.49	0.33	0.43
U13987	/	−1.19	0/0	0.34
E00532	−0.40	−0.49	6.93e−4/0	6.18e−4/0
L10292	0.24	−0.26	6.17e−4/0	0.46
AB030491	/	−1.07	0/0	0/0
AF079058	0.74	/	0.00	0/0
D31700	−1.49	−1.50	0.00	0.00
J01298	0.22	0.24	6.40e−4/5.07e−4	0.15
AF089850	0.85	−1.06	0.00	0.12
M94012	1.65	−0.40	1.39e−3/0	1.65e−3/0
AB004062	−0.45	1.61	5.26e−4/0	2.69e−3/0
M11317	1.02	−1.27	0.58	0.60
Average	0.33	−0.65

R1 represents plant-environment interaction related reference genes, which include EU450800, the disease resistance gene Rps1-k-1; L20310, nodulin (nod-20) gene and D13505, early nodulin related gene; R2 signifies other fourteen reference genes.

C, Cultivars; W, Wild soybeans; All, Cultivars and Wild soybeans.

^*0.01<P<0.05;

^**0.001<P<0.01;

^*** P<0.001.