Table 1.

The F-values for the effects of subspecies, breeding type, year of release and their interaction on grain quality traits of rice.

Factors	Head rice rate	Chalky rice rate	Chalkiness degree	Gel consistency	Amylose content	Length-to-width ratio
Subspecies (japonica, indica)	50.38***	33.60***	2.83ns	245.68***	142.38***	–
Breeding type (hybrid, inbred)	579.91***	82.83***	39.13***	639.78***	629.30***	0.20ns
Year of release	54.76***	17.23***	23.04***	86.48***	5.71**	5.37**
Subspecies × breeding type	9.81**	0ns	40.33***	0ns	0ns	–
Subspecies × year of release	27.17***	11.23***	0.73ns	37.34***	2.76ns	–
Breeding type × year of release	0ns	0ns	0ns	40.95***	5.3**	53.72***
Subspecies × breeding type × year of release	0ns	31.93***	8.12***	0ns	22.43***	–

^∗∗Significant at 0.01 probability level; ^∗∗∗Significant at 0.001 probability level; ns, not significant.