Genotypic differences in grain yield, and nitrogen absorption and utilization in recombinant inbred lines of rice under hydroponic culture

Figures & data

Table 1 Grain yield and yield components, NTA and NUEg of Shanyou 63 (SY 63) and parents (ZX 97 and MH 63) in 2000 and of the RILs in 2000 and 2001

Traits	2000			RILs
	Female parent (ZX 97) Mean ± SD	F1 hybrid (SY 63) Mean ± SD	Male parent (MH 63) Mean ± SD	2000 (F12)				2001 (F13)
				Mean ± SD	Sig.	Max.	Min.	Mean ± SD	Sig.	Max.	Min.
Grain yield (g m^−2)	128.0 a ± 0.4	909.0 c ± 40.3	754.0 b ± 80.1	634.0 ± 167.9	0.000	1080.0	207.0	533.0 ± 143.7	0.000	957.0	178.0
No. panicles m^−2	168.0 a ± 8.8	317.3 b ± 8.8	369.1 b ± 34.2	285.2 ± 46.4	0.000	496.0	198.4	297.6 ± 52.3	0.000	477.4	179.8
No. spikelets panicle^−1	59.9 a ± 4.0	108.8 c ± 3.1	74.9 b ± 3.5	104.1 ± 20.2	0.009	157.5	62.3	91.5 ± 19.8	0.000	152.8	46.8
Filled grain percentage (%)	51.8 a ± 0.5	86.4 b ± 3.4	86.1 b ± 4.3	77.4 ± 11.4	0.000	95.5	30.4	70.5 ± 10.9	0.000	91.3	32.7
1000-grain weight (g)	21.1 a ± 0.0	26.3 b ± 0.2	27.4 b ± 1.0	23.9 ± 2.7	0.055	30.3	17.4	24.7 ± 2.9	0.193	31.8	17.3
NTA (g m^−2)	4.3 a ± 0.1	18.2 c ± 0.9	17.6 bc ± 4.3	16.9 ± 4.06	0.000	28.1	9.0	15.3 ± 3.38	0.000	24.2	6.9
NUEg (gGW gN^−1)	29.6 a ± 0.7	49.8 c ± 4.7	42.8 b ± 5.3	37.9 ± 7.2	0.000	55.8	14.1	35.6 ± 9.4	0.000	65.9	13.8
NTA, total nitrogen absorption; NUEg, nitrogen use efficiency for grain yield; RILs, recombinant inbred lines; Sig, significant difference value. Values followed by the same letter in a column are not significantly different (P = 0.05).

Table 2 Grain yield and yield components, NTA and NUEg in each cluster of the RILs grown in 2000 and 2001

Cluster^†	N	Yield^†		No. panicles (m^−2)		No. spikelets panicle^−1		1000-grain weight^‡ (g)		Filled grain percentage (%)		NTA (g m^−2)		NUEg (gGW gN^−1)
		Mean	CV (%)	Mean	CV (%)	Mean	CV (%)	Mean	CV (%)	Mean	CV (%)	Mean	CV (%)	Mean	CV (%)
2000
A	7	1028 a	3.4	353.4 a	8.0	116.5 a	8.2	26.1 a	11.7	84.1 a	6.4	25.1 a	6.8	41.1 a	6.4
B	18	835 b	7.3	328.6 a	19.0	116.6 a	21.2	23.5 bc	11.8	83.6 a	7.9	21.0 b	15.5	40.6 a	14.9
C	40	654 c	5.3	285.2 b	12.9	103.7 ab	16.6	24.0 bc	10.3	82.0 a	9.5	16.4 c	13.6	40.3 a	12.1
D	38	543 d	7.1	272.8 bc	10.4	98.6 bc	17.8	24.3 ab	10.2	73.5 b	13.7	15.3 d	20.9	36.8 b	20.2
E	13	414 e	8.8	248.0 c	12.3	100.2 ab	24.3	22.5 c	12.6	67.9 b	17.5	13.7 e	19.4	31.5 c	23.2
F	2	224 f	10.6	279.0 bc	1.6	85.1 c	29.3	21.9 c	15.7	39.7 c	33.2	13.3 e	42.6	18.6 d	33.8
Total	118	634	26.5	285.2	16.1	104.1	19.4	23.9	11.2	77.4	14.8	16.9	24.0	37.9¡¡	19.0
2001
A	13	825 a	6.8	303.8 ab	20.4	112.3 a	16.0	26.2 a	11.2	82.2 a	8.9	17.4 ab	14.7	48.0 a	12.3
B	22	696 b	3.9	322.4 a	12.8	102.7 a	17.5	24.3 ab	12.8	77.2 ab	10.4	17.6 a	16.0	40.4 b	15.7
C	63	584 c	5.8	310.0 a	16.5	92.4 b	19.8	25.1 ab	11.3	73.2 b	10.1	16.2 b	18.5	37.4 c	21.1
D	59	479 d	6.9	285.2 b	16.5	90.5 b	20.1	24.5 ab	11.9	69.3 c	13.9	14.3 cd	23.5	35.2 c	23.7
E	15	375 e	4.7	272.8 bc	16.3	78.5 c	18.3	24.2 ab	10.0	64.7 c	12.2	13.4 de	19.4	29.1 d	20.4
F	19	272 f	17.8	254.2 c	18.0	74.9 c	22.0	24.0 b	10.5	54.4 d	20.1	12.7 e	21.9	22.3 e	24.1
Total	191	533	26.9	297.6	17.8	91.5	21.6	24.7	11.6	70.5	15.4	15.3	22.1	35.6	26.5
CV, coefficient of variance; N, number of lines; NTA, total nitrogen absorption; NUEg, nitrogen use efficiency for grain yield. Values followed by the same letter in a column are not significantly different (P = 0.05). ^†Clusters A to F represent high to low grain yield, respectively.
^‡Moisture content is 13.5%.

Table 3 Correlation coefficients between grain yield and yield components or NTA and NUEg of RILs grown in 2000 and 2001

	No. panicles (m^−2)	No. spikelets panicle^−1	No. spikelets (m^−2)	Filled grain percentage (%)	1000-grain weight (g)	Pre-NTA (g m^−2)	Post-NTA (g m^−2)	NTA (g m^−2)	NUEg (gGW N^−1)	Grain yield (g m^−2)
2000
No. panicles m^−2	1.000
No. spikelets panicle^−1	−0.216*	1.000
No. spikelets m^−2	0.492**	0.728**	1.000
Filled grain percentage (%)	0.177 ns	−0.153 ns	−0.005 ns	1.000
1000-grain weight (g)	0.075 ns	−0.384**	−0.282**	−0.001 ns	1.000
Pre-NTA (g m^−2)	0.417**	0.075 ns	0.373**	0.081 ns	0.300**	1.000
Post-NTA (g m^−2)	0.201*	0.169ns	0.272*	0.227*	0.075 ns	−0.185*	1.000
NTA (g m^−2)	0.490**	0.187 ns	0.507**	0.235*	0.301*	0.678**	0.597**	1.000
NUEg (gGW gN^−1)	0.148 ns	0.216*	0.310*	0.472**	−0.106 ns	0.108 ns	−0.165 ns	−0.278*	1.000
Grain Yield (g m^−2)	0.568**	0.331**	0.704**	0.548**	0.193*	0.515**	0.401**	0.722**	0.447**	1.000
2001
No. panicles m^−2	1.000
No. spikelets panicle^−1	−0.359**	1.000
No. spikelets m^−2	0.411**	0.691**	1.000
Filled grain percentage (%)	0.137 ns	0.051 ns	0.145 ns	1.000
1000-grain weight (g)	−0.005 ns	−0.241**	−0.285**	−0.096 ns	1.000
Pre-NTA (g m^−2)	0.219**	0.107 ns	0.260**	0.044 ns	0.071 ns	1.000
Post-NTA (g m^−2)	0.313**	0.126 ns	0.388**	0.035 ns	−0.080 ns	−0.211**	1.000
NTA (g m^−2)	0.423**	0.186 ns	0.516**	0.063 ns	−0.007 ns	0.630**	0.626**	1.000
NUEg (gGW gN^−1)	0.011 ns	0.327**	0.315**	0.597**	0.169*	−0.242**	−0.211**	−0.361*	1.000
Grain yield (g m^−2)	0.364**	0.468**	0.735**	0.625**	0.148 ns	0.265**	0.291**	0.443**	0.646**	1.000
NTA, total nitrogen absorption; NUEg, nitrogen use efficiency for grain yield; Pre-NA, pre-heading nitrogen absorption; Post-NA, post-heading nitrogen absorption. Significant difference at *P = 0.05 and
**P = 0.01; ns, not significant at P = 0.05.

Table 4 Results of multiple regression analysis and contribution ratios

Resultant trait	Component trait	R^2		Contribution ratio (%)
		2000	2001	2000	2001
Y1:	X1: No. panicles per hill			31.8	32.2
Grain yield (g m^−2)	X2: No. spikelets per panicle	0.803	0.808	26.0	25.5
	X3: Filled grain percentage			24.4	24.1
Y2:	X4: Pre-NA	1.000	1.000	76.7	78.7
NTA (g m^−2)	X5: Post-NA			23.3	21.3
Y3:	X6: NUEg	0.978	0.943	56.3	56.6
Grain yield (g m^−2)	X7: NTA			43.7	43.4
NTA, total nitrogen absorption; NUEg, nitrogen use efficiency for grain yield; Pre-NA, pre-heading nitrogen absorption; Post-NA, post-heading nitrogen absorption.

Figure 1  Relationship between total nitrogen absorption (NTA) and nitrogen use efficiency for grain yield (NUEg) among recombinant inbred lines (RILs) in (A) 2000 and (B) 2001. The curve lines in the figure indicate the iso-grain yield. Grain yield = NTA × NUEg. Numerals on the right side in both (A) and (Bb) indicate the grain yield (g m−2), **P = 0.01. Clusters A–F in the figure correspond to those in Table 2.