Table 2. Grain-related traits measured using SmartGrain software in the selected early flowering lines and their four parental cultivars.

Line	Area size (mm2)	Perimeter length (mm)	Grain length (mm)	Grain width (mm)	Length-width ratio	Circularity
Yukichikara	16.4 ± 1.6	17.3 ± 0.9	6.9 ± 0.4	3.1 ± 0.2	2.2 ± 0.16	0.7 ± 0.0
SB3#3	14.2 ± 2.5**	16.3 ± 1.3**	6.5 ± 0.5**	2.8 ± 0.3**	2.3 ± 0.2*	0.7 ± 0.0*
SB11-1#3	16.1 ± 2.1	17.7 ± 1.0	7.1 ± 0.4*	3.0 ± 0.3*	2.4 ± 0.3**	0.7 ± 0.1**
SB11-2#3	17.5 ± 2.3**	17.8 ± 1.1**	7.1 ± 0.5**	3.2 ± 0.3	2.3 ± 0.2	0.7 ± 0.0
Kitanokaori	14.8 ± 2.0	16.2 ± 1.1	6.4 ± 0.5	3.0 ± 0.3	2.2 ± 0.2	0.7 ± 0.1
SB9#2	15.9 ± 2.5*	17.7 ± 1.3**	7.2 ± 0.5**	2.8 ± 0.3**	2.6 ± 0.3**	0.6 ± 0.1**
SB16-1#1	18.6 ± 2.0**	18.2 ± 0.8**	7.2 ± 0.3**	3.3 ± 0.3**	2.2 ± 0.2	0.7 ± 0.0
SB16-1#2	18.6 ± 2.4**	18.4 ± 1.1**	7.4 ± 0.43**	3.3 ± 0.3**	2.3 ± 0.2**	0.7 ± 0.0
Haruyokoi	19.0 ± 2.0	18.0 ± 0.9	7.0 ± 0.4	3.5 ± 0.2	2.0 ± 0.1	0.7 ± 0.0
SB12#1	17.3 ± 2.2**	17.7 ± 1.1	7.1 ± 0.5	3.1 ± 0.3**	2.3 ± 0.2**	0.7 ± 0.1**
SB13-2#1	17.8 ± 2.3**	18.3 ± 1.3*	7.4 ± 0.6**	3.1 ± 0.2**	2.4 ± 0.2**	0.7 ± 0.0**
Haruhinode	16.6 ± 2.0	16.5 ± 1.0	6.3 ± 0.4	3.4 ± 0.2	1.8 ± 0.1	0.8 ± 0.0
SB14#3	19.3 ± 2.6**	18.6 ± 1.2**	7.4 ± 0.4**	3.4 ± 0.3	2.2 ± 0.2**	0.7 ± 0.0**

Significant differences between each selected early flowering line and its parental cultivar were indicated by asterisks (*P < 0.05; **P < 0.01).