Response of Rice Nitrogen Physiology to High Nighttime Temperature during Vegetative Stage
Table 1
Night temperature effect on the plant height, maximum root length, root volume, root number, leaf area, and shoot and root dry weights of rice seedlings.
Nitrogen level (N)
Temp. (T)
Plant height (cm)
Maximum root length (cm)
Root volume (cm3 plant−1)
Root number (plant−1)
Leaf area (cm2 plant−1)
Shoot dry weight (g/100 plants)
Root dry weight (g/100 plants)
160
22°C
42.87 ± 1.49b
15.58 ± 3.10b
0.92 ± 0.08a
92 ± 16a
49.3 ± 8.3b
5.82 ± 0.20b
2.41 ± 0.21a
27°C
45.53 ± 1.06a
17.38 ± 3.75b
1.01 ± 0.11a
83 ± 14a
55.9 ± 6.8a
6.40 ± 0.28a
2.20 ± 0.19a
40
22°C
39.88 ± 2.43b
17.46 ± 2.61b
0.82 ± 0.14ab
72 ± 20ab
42.8 ± 3.6c
5.51 ± 0.10c
2.23 ± 0.15a
27°C
44.33 ± 1.82a
20.58 ± 2.56ab
0.80 ± 0.09b
85 ± 18ab
48.7 ± 9.1b
6.01 ± 0.19b
2.05 ± 0.03ab
10
22°C
40.71 ± 1.65b
18.63 ± 2.10b
0.75 ± 0.13b
66 ± 16b
35.3 ± 3.6d
5.02 ± 0.26d
1.97 ± 0.11bc
27°C
40.17 ± 1.77b
23.99 ± 2.46a
0.72 ± 0.14b
56 ± 12b
39.6 ± 6.8c
5.27 ± 0.10d
1.68 ± 0.01c
ANOVA
N
*
**
**
**
**
**
**
T
**
**
ns
ns
**
**
**
N * T
ns
ns
ns
ns
ns
ns
ns
Rice seedlings were grown under two different night temperatures of 22°C and 27°C with three nitrogen levels of 10 mg N/L, 40 mg N/L, and 160 mg N/L. Values were expressed as means ± standard error (), and the same small letter in the same column means that the values are not significantly different at by Tukey’s HSD.
