Table 1 Agronomic traits (mean ± standard deviation) and drought-tolerance index (DTI) evaluated on twelve rice genotypes under well-watered (W) and drought (D) conditions. “*”, “**”, and “***” indicate significant differences between W and D at p < 0.05, p < 0.01, and p < 0.001 via independent t test. DTIB or DTIY is calculated as P_d/P_W*(P_d/P_ad). P_d is referred as biomass/yield in D, P_w is referred as biomass/yield in W, and P_ad is referred as averaged biomass/yield of total rice genotypes in D

S3

IAC1246^b

0.241

68.0 ± 1.4

80.4 ± 6.1

28.35 ± 2.00

19.64 ± 0.75*

10.65 ± 0.32

7.89 ± 0.42**

0.402 ± 0.025

0.378 ± 0.029

1.053

1.680

S6

Hanhui-3^b

0.359

51.0 ± 0.8

23.7 ± 4.5**

27.60 ± 1.99

19.23 ± 1.16*

7.61 ± 0.29

1.17 ± 0.30***

0.063 ± 0.036

0.278 ± 0.035***

1.037

0.052

S9

CICA4^a

0.410

69.2 ± 2.6

56.0 ± 10.6

13.67 ± 1.16

8.03 ± 0.73*

6.34 ± 0.54

2.03 ± 0.53**

0.244 ± 0.082

0.463 ± 0.012**

0.365

0.186

S11

Aimi ^b

0.405

76.9 ± 8.0

82.8 ± 2.9

25.11 ± 3.64

17.56 ± 1.73*

11.17 ± 0.39

7.82 ± 0.50**

0.448 ± 0.027

0.450 ± 0.050

0.950

1.571

S12

Zhonghan-3^a

0.435

79.3 ± 1.9

67.8 ± 4.9

19.78 ± 1.01

8.50 ± 0.63**

9.49 ± 0.47

2.45 ± 0.12***

0.289 ± 0.015

0.480 ± 0.024***

0.283

0.181

S14

Yunlu^a

0.509

73.2 ± 2.3

81.7 ± 2.5

19.70 ± 2.73

11.34 ± 0.62**

7.41 ± 0.50

3.31 ± 0.15***

0.292 ± 0.005

0.378 ± 0.022*

0.505

0.425

S17

Qingsizhan ^b

0.416

88.5 ± 1.8

47.8 ± 3.6**

20.79 ± 0.79

13.69 ± 1.60*

10.49 ± 0.65

2.05 ± 0.20***

0.151 ± 0.023

0.504 ± 0.022***

0.698

0.115

S18

IRAT109 ^a

0.468

77.2 ± 6.9

52.8 ± 13.0

16.45 ± 2.30

7.90 ± 1.00*

8.56 ± 1.45

1.84 ± 0.49*

0.252 ± 0.169

0.517 ± 0.059**

0.293

0.113

S24

IPECA0162 ^a

0.366

87.7 ± 2.8

54.5 ± 14.8

14.20 ± 0.27

6.93 ± 0.64***

7.26 ± 0.34

1.51 ± 0.50**

0.235 ± 0.166

0.511 ± 0.034**

0.261

0.090

S26

Bulebelle ^a

0.435

70.9 ± 0.5

60.7 ± 4.9

18.17 ± 1.10

10.21 ± 0.91*

9.27 ± 0.74

4.26 ± 0.67**

0.413 ± 0.050

0.509 ± 0.018

0.444

0.563

S28

Tresmes ^b

0.441

84.0 ± 2.7

64.3 ± 14.4

29.88 ± 0.26

18.75 ± 2.60*

13.30 ± 0.33

4.76 ± 0.96**

0.270 ± 0.137

0.445 ± 0.015*

0.911

0.488

S31

Huhan-1B ^b

0.384

74.6 ± 0.7

43.8 ± 2.2***

26.14 ± 1.49

13.32 ± 0.96**

11.76 ± 0.44

2.71 ± 0.20***

0.204 ± 0.007

0.451 ± 0.029**

0.525

0.179