Effect of flag leaf length of erect panicle rice on the canopy structure and biomass production after heading

Figures & data

Table 1. Daily average temperature and solar radiation during the rice growth periods in 2015 and 2016

Month		Temperature (°C)		Solar Radiation (MJ m^−2 d^−1)
		2015	2016	2015	2016
May	Late	22.0	22.9	23.6	18.2
June	Early	20.3	21.6	16.6	20.1
	Middle	22.7	24.0	14.1	14.5
	Late	22.8	23.3	17.6	11.2
July	Early	23.5	28.0	12.0	15.9
	Middle	27.6	27.3	17.7	15.1
	Late	27.8	27.6	16.9	17.8
August	Early	30.1	29.8	21.4	21.8
	Middle	26.6	29.1	14.6	18.6
	Late	25.5	27.8	13.6	16.4
September	Early	23.1	27.1	9.9	16.0
Mean		24.7	26.2	16.2	16.9

Table 2. Yield, yield components, and agronomic traits of two rice progenitors and the erect panicle (EP) and non-erect panicle (nEP) type of RILs in 2015

	EP RILs	nEP RILs		Progenitors
				Liaojing5	Wanlun422
Yield	7.24	7.48	ns	7.05	8.96	*
TDW	14.3	15.2	**	14.5	15.4	ns
HI	0.51	0.49	ns	0.49	0.58	*
PN	268	299	*	419	296	**
GN	167	130	**	108	156	**
SSR	0.78	0.81	ns	0.69	0.77	ns
TGW	18.9	21.9	**	19.8	22.0	**
PH	105	111	ns	104	102	ns
LAI	4.24	4.70	**	4.28	4.56	ns
FLL	27.4	33.5	**	27.6	28.1	ns
PL	18.9	22.8	**	15.7	23.7	**

Notes: grain yield (Yield, t ha⁻¹), total dry weight (TDW, t ha⁻¹), harvest index (HI), panicle number (PN, m⁻²), grain number per panicle (GN), seed setting rate (SSR), 1000-grain weight (TGW, g), plant height (PH, cm), leaf area index (LAI), flag leaf length (FLL, cm), panicle length (PL, cm), and panicle angle (PA, º). * and **: indicate significance at the 0.05 and 0.01 probability levels, respectively. ns indicates non-significance at P = 0.05.

Table 3. Pearson partial correlation coefficients for yield, yield components, and agronomic traits of 23 EP RILs and 35 nEP RILs in 2015

	YIELD	TDW	HI	PN	GN	SSR	TGW	PH	LAI	FLL	PL
YIELD		0.52	0.86	0.37	0.08	0.57	0.12	0.21	0.09	0.05	0.18
TDW	0.25		0.01	0.12	0.07	0.67	−0.06	0.57	0.27	0.33	0.16
HI	0.84	−0.31		0.34	0.07	0.29	0.16	−0.08	−0.07	−0.13	0.14
PN	0.58	0.09	0.52		−0.70	0.20	0.07	−0.29	−0.34	−0.34	−0.37
GN	0.07	0.22	−0.08	−0.45		−0.20	−0.51	0.42	0.30	0.24	0.32
SSR	0.21	−0.13	0.32	0.24	−0.78		0.13	0.39	0.14	0.33	0.24
TGW	0.04	−0.16	0.15	0.33	−0.71	0.41		−0.29	−0.06	−0.04	−0.06
PH	−0.27	0.47	−0.53	−0.28	0.28	−0.27	−0.33		0.40	0.76	0.37
LAI	−0.61	0.01	−0.59	−0.32	0.10	−0.35	−0.20	0.17		0.30	0.09
FLL	−0.52	0.07	−0.55	−0.65	0.51	−0.50	−0.44	0.46	0.41		0.35
PL	0.06	0.15	−0.02	−0.16	0.18	−0.07	0.01	0.03	0.14	0.39

Notes: Above diagonal for the data of nEP RILs; below diagonal for the data of EP RILs. grain yield (Yield, t ha⁻¹), total dry weight (TDW, t ha⁻¹), harvest index (HI), panicle number (PN, m⁻²), grain number per panicle (GN), seed setting rate (SSR), 1000-grain weight (TGW, g), plant height (PH, cm), leaf area index (LAI), flag leaf length (FLL, cm), and panicle length (PL, cm). Grey represents significant correlations at the 0.05 probability level.

Figure 1. Relationship between the flag leaf length (cm) and (a) sink capacity (g m⁻²) and (b) source amount (mg grain⁻¹) in EP RILs in 2015. * represents Liaojin5, an EP progenitor.

Figure 2. Relationship between the flag leaf length and the (a) non-structural carbohydrates in stems per grain at heading (NSC, mg grain⁻¹), (b) biomass increase per grain from heading to 15 days after heading (∆W_HD-15DAH, mg grain⁻¹), and (c) biomass increase per grain from 15 days after heading to maturity (∆W_15DAH-MAT, mg grain⁻¹) in EP RILs in 2015. * represents Liaojin5, an EP progenitor.

Table 4. Yield, yield components, and agronomic traits of two rice progenitors and the erect panicle (EP) type of RILs in 2016

	Yield	TDW	HI	PN	GN	SSR	TGW	PH	LAI	FLL	PL	PA
EP
Short	8.57	14.7	0.58	281	152	0.86	20.4	97	3.98	23.1	18.8	13.3
Long	8.04	15.2	0.53	249	210	0.75	18.2	111	3.59	32.6	19.5	25.0
(Liaojing5)	8.42	15.9	0.53	372	119	0.82	20.5	105	4.8	31.2	16.4	2.3
nEP
Short	7.78	14.2	0.55	273	145	0.81	21.9	101	3.46	28.2	24.8	54.9
Long	8.26	15.3	0.54	260	140	0.89	23.2	122	4.82	40.1	23.0	39.6
(Wanlun422)	9.70	15.3	0.63	279	173	0.82	21.6	101	4.31	29.8	25.9	59.3
ANOVA
Group (G)	ns	ns	ns	ns	**	**	**	**	**	**	**	**
Length (L)	ns	*	**	*	**	ns	ns	**	**	**	*	ns
G*L	*	ns	**	ns	**	**	**	**	**	ns	**	**

Notes: short flag leaf length lines (EP_short, nEP_short), long flag leaf length lines (EP_long, nEP_long), grain yield (Yield, t ha⁻¹), total dry weight (TDW, t ha⁻¹), harvest index (HI), panicle number (PN, m⁻²), grain number per panicle (GN), seed setting rate (SSR), 1000-grain weight (TGW, g), plant height (PH, cm), leaf area index (LAI), flag leaf length (FLL, cm), panicle length (PL, cm), and panicle angle (PA, º). * and **: indicate significance at the 0.05 and 0.01 probability levels, respectively.

Table 5. Averages and the results of ANOVA for the leaf area index (LAI) distribution parameters: mean LAI distribution (a₁) and the variance of LAI distribution (a₂) in the heading stage, and at 15 and 30 days after heading (15 DAH and 30 DAH, respectively)

	Heading		15 DAH		30 DAH
	a1	a2	a1	a2	a1	a2
EP
Short	0.554	0.051	0.578	0.050	0.613	0.046
Long	0.574	0.055	0.628	0.051	0.701	0.039
nEP
Short	0.627	0.043	0.641	0.035	0.684	0.037
Long	0.584	0.045	0.62	0.04	0.662	0.033
ANOVA
Group (G)	**	**	*	**	ns	*
Length (L)	ns	ns	ns	ns	*	ns
G*L	**	ns	**	ns	**	ns

Notes: * and **: indicate significance at the 0.05 and 0.01 probability levels, respectively. ns indicates non-significance at P = 0.05.

Table 6. Averages and the results of ANOVA for SPAD values of first, second, and third upper leaves at 7, 14, 28 days after heading (7 DAH, 14 DAH, and 28 DAH, respectively) and SPAD decline rate (7DAH to 28DAH)

	7DAH			14DAH			28DAH			SPAD decline rate (%)
	1st	2nd	3rd	1st	2nd	3rd	1st	2nd	3rd	1st	2nd	3rd
EP
Short	42.4	43.3	44.8	44.4	45.8	46.3	41.8	43.6	40.5	1.4	−0.6	9.6
Long	44.3	45.1	44.4	45.2	45.9	44.3	44.2	42.2	38.8	0.2	6.4	12.6
non-EP
Short	44.5	44.9	44.4	44.8	45.5	45.4	43	42.1	39.7	3.3	6.2	10.6
Long	41.7	40.9	40.7	41.3	41.9	42.1	40.1	40.3	36.0	3.8	1.5	11.6
ANOVA
Group (G)	ns	*	**	**	**	**	*	*	ns	ns	ns	ns
Length (L)	ns	ns	**	**	**	**	ns	*	*	ns	ns	ns
G*L	**	**	**	**	**	ns	**	ns	ns	ns	**	ns

Notes: EP RILs with short flag leaves (FL_short), EP RILs with long flag leaves (FL_long). * and **: indicate significance at the 0.05 and 0.01 probability levels, respectively. ns indicates non-significance at P = 0.05.