Table 1.

Information on four rice cultivars selected for the study.

Cultivara	Ecotype	Gene frequencies		Stress toleranceb	Sowing date	Bootingd	Anthesis	Grain-filling stage
		Indica	Japonica
Yongyou9	Subspecies Indica ×Japonica	0.458	0.542	Chilling sensitive	June 14	September 8–10	September 11–13	October 1–3
Yongyou17	Subspecies Indica ×Japonica	0.477	0.524		June 14	September 9–10	September 12–13	October 2–3
Yongyou538	Subspecies Indica ×Japonica	0.459	0.541	Chilling tolerant	June 21c	September 1–3	September 4–6	September 24–26
Zhejing88	O. japonica	0.100	0.900		June 14	September 2–5	September 5–8	September 25–28

^aCultivars are from the China National Rice Research Institute (CNRRI), China. ^bThe results are derived from those of the study of Zeng et al. (2015). ^cYongyou538, which has a shorter growth duration, was sown 1 week later than other cultivars to maintain a synchronous time of flowering. ^dThe booting stage, anthesis, and grain filling were recorded in both 2013 and 2014.