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Supporting information
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4
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Supplementary Table 1. Plant type of the tested maize hybrids
Cultivars
Plant type
References
ZD 2
H 417
DY 13
ND 60
YD 13
ND108
ZD 958
XD20
XY335
Spreading leaves
Semi-upright leaves
Spreading leaves
Upright leaves
Upright leaves
Semi-upright leaves
Upright eaves
Upright leaves
Upright leaves
Xing YW, Shi XH, Wang KL et al., 2005
Zhang JP, Zhang YP, Cao HW et al., 2010
Xing YW, Shi XH, Wang KL et al., 2005
Feng HM, 1992
Guo YQ, Dong ST, Wang KJ et al., 2003
Guo J, Guo XY, Wang JH et al., 2005
Wang CH, Ou XQ, Wang H, 2009
Zhang SL, Chang JZ, Cheng XJ et al., 2007
Xu MJ, Liu J, Dong QT et al., 2009
Feng HM (1992) Preliminary study on the cultivation of maize hybrid ND60. Applied Techniques
and Development. 7, 31-32 (In Chinese).
7
Guo J, Guo XY, Wang JH et al. (2005) Characteristics parameters of light responses of corn
8
varieties with different plant shapes. Acta Botanica Boreali-Occidentalia Sinica, 25, 1612-1617
9
(In Chinese).
10
Guo YQ, Dong ST, Wang KJ et al. (2003) Adjustment of colony kernel and leaf physiological
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characteristics of different spike type maize (Zea Mays L.). Acta Agronomica Sinica, 29, 626-
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632 (In Chinese).
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14
15
16
17
18
Wang CH, Ou XQ, Wang H (2009) Studies on physiology and ecology of zhengdan 958 etc. High
Yield Varieties. Seed, 28, 41-44 (In Chinese).
Xing YW, Shi XH, Wang KL et al. (2005) Studies on the production and agronomic traits of
different pant type maize hybrids. Journal of Maize Sciences, 13, 92-94 (In Chinese).
Xu MJ, Liu J, Dong QT et al. (2009) Preliminary study on proper cultivation density and character
index of Xianyu 335. Journal of Anhui Agricultural Sciences, 37, 8928-8930 (In Chinese)
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Zhang JP, Zhang YP, Cao HW et al. (2010) Preliminary Analysis of the breeding strategy for
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summer maize in Huang-Huai-Hai Plain. Journal of Henan Agricultural Sciences, 9, 151-153
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(In Chinese).
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23
Zhang SL, Chang JZ, Cheng XJ et al. (2007) Characteristics of New Maize Varieties Xundan No.
20 and Its High Yield Cultivation Technology. Seed, 26, 98-99 (In Chinese).
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Supplementary Table 2. Nitrogen remobilization efficiency and N harvest index of nine
maize hybrids under different N supplies
N remobilization efficiency (%)
N0
N harvest index (%)
N240
N0
N120
N240
ZD2
H417
34.6
73.8
d
a
42.8
60.0
cd
ab
42.6
53.5
de
ab
64.6
70.0
bcd
ab
66.4
70.1
bc
ab
63.5
64.9
b
b
DY13
ND60
62.6
50.4
ab
abcd
49.4
62.3
cd
ab
48.8
61.3
bcd
a
63.1
65.4
cd
cd
60.6
69.6
d
b
60.0
67.8
c
b
YD13
ND108
55.6
39.2
abc
bcd
47.5
38.8
bcd
d
40.2
47.4
e
bcd
62.9
60.4
cd
d
64.4
61.4
cd
d
60.9
59.9
c
c
ZD958
XD20
XY335
37.0
58.1
cd
ab
51.0
53.6
cd
abc
51.5
46.8
bc
cd
65.1
66.6
72.3
bcd
abc
a
67.2
70.2
74.2
bc
b
a
64.7
64.7
69.3
b
b
a
CV%
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N120
51.3 bcd
25.1
68.0 a
18.0
54.1 ab
12.9
5.58
6.59
Note: Different letters in the same column denote significant difference at p<0.05 probability level between two maize hybrids
28
2
5.16
30
31
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
135
140
145
150
155
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Precipitation (mm)
90
45
80
40
70
35
60
30
50
40
30
Precipitation (mm)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
135
140
145
150
155
Growing degree days (℃)
12
10
8
6
4
Growing degree days (℃)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
135
140
145
150
155
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
Sunshine hours (h)
10
8
6
Sunshine hours (h)
16
14
14
12
12
10
4
16
14
32
3
8
6
4
2
2
0
0
20
Days after sowing
18
Days after sowing
18
16
14
12
10
8
6
2
4
2
0
0
Days after sowing
Days after sowing
25
20
20
15
10
10
5
0
0
Days after sowing
Days after sowing
Supplementary Figure 1. Weather data in the experimental location Siping in 2010 and
2011
16000
Potential yield (kg ha -1 )
14000
12000
10000
8000
6000
4000
2000
y = 107.9x - 20574
r = 0.60**
0
1970
1980
1990
2000
2010
2020
Year
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Supplementary Figure 2. Potential yield of each year × hybrid combination from 1973 to 2011.
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Yield potential was simulated by matching each maize hybrid to the climatic conditions of the
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year(s) in which it was grown, e.g. ZD2 was used to simulate the yield potential from 1973 to
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1977 and H417 was used to simulate the yield potential for 1978. This method indicated that
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modern breeding increased yield potential by 108 kg ha−1 yr−1 on average. In 1973 the yield
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potential simulated with the hybrid ZD2 was 7314 kg ha−1, whereas in 2011 the yield potential
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rose to 11,430 kg ha−1 as simulated with the hybrid XY335.
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4
65
Harvest index (%)
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y = 0.185x - 315.0
r = 0.63 NS
55
50
45
40
35
y = 0.285x - 517.5
r = 0.72*
A
LN
HN
30
1970 1975 1980 1985 1990 1995 2000 2005
Year of hybrid release
Ear numbers per unit area (plant ha -1 )
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60000
y = 281.8x - 50759
r = 0.68*
55000
50000
45000
y = 508.4x - 96114
r = 0.94**
40000
B
LN
HN
35000
1970 1975 1980 1985 1990 1995 2000 2005
Year of hybrid release
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Supplementary Figure 3. Relationship between the year of hybrid release and harvest index
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(A), and ear numbers per unit area (B).
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5
14
Yield / sunshine hours during
growth period (kg ha -1 h -1 )
12
10
8
6
4
2
y = 0.169x - 328.6
r = 0.85**
0
1970
1980
1990
Yield / growing degree days during
growth period (kg ha -1 ℃-1 )
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2020
10
8
6
4
2
1970
y = 0.062x - 118.8
r = 0.56**
1980
1990
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Yield / precipitation during growth
period (kg ha -1 mm -1 )
2010
12
0
2000
Year
2010
2020
60
50
40
30
20
10
y = 0.436x - 849.4
r = 0.54**
0
1970
49
50
51
52
2000
Year
1980
1990
2000
Year
2010
2020
Supplementary Figure 4. Sunshine hours, Thermal time, and Water use efficiency in maize
hybrids released since 1973. Maize yields of different eras were simulated using Maize-Hybrid
model.
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6
Type I: Early-senescent
Type II: late-senescent
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Supplementary Figure 5. Cluster analysis of 9 maize hybrids based on leaf senescence
traits.
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