Table 4.

The variation coefficients for quality traits of inbred and hybrid rice varieties registered from 2000 to 2014.

Rice type	Year	Head rice rate	Chalky rice rate	Chalkiness degree	Gel consistency	Amylose content	Length-to-width ratio
Japonica inbred	2000–2004	7.37	76.8	88.58	7.81	6.44	–
	2005–2009	4.95	61.18	63.67	5.06	5.11	–
	2010–2014	4.97	47.6	58.81	3.65	4.57	–
	Mean	5.76ab	61.86a	70.35a	5.51c	5.37a	–
Japonica hybrid	2000–2004	5.89	44.54	65.25	11.22	8.87	–
	2005–2009	6.25	44.37	54.28	7.55	16.24	–
	2010–2014	4.23	57.43	76.72	7.04	3.69	–
	Mean	5.46b	48.78a	65.42a	8.6c	9.6a	–
Indica inbred	2000–2004	14.66	114.91	165.68	23.24	27.06	8.39
	2005–2009	15.71	70.07	76.5	23.32	26.81	18.35
	2010–2014	4.24	3.72	22.19	26.51	4.21	7.51
	Mean	11.54ab	62.9a	88.12a	24.36	19.36a	11.42a
Indica hybrid	2000–2004	13.15	53.66	79.62	22.74a	11.68	11.34
	2005–2009	12.56	65.24	78.68	17.08	16.07	10.73
	2010–2014	10.45	57.44	70.38	18.03	18.81	9.03
	Mean	12.05a	58.78a	76.23a	19.28b	15.52a	10.37a

Bold values mean that variation of traits was lower when compared with those of older varieties; mean values followed by the same letter do not significantly differ at the 5% probability level.