Table 1. Nine chicken populations were surveyed in this study.

Breeds	Abbreviation	Location	Sample size	Altitude1	Group	Latitude1	Longitude1
Tibetan chicken	T	Ganzi, Sichuan	30	2930 m	High	28° 55′ 52.25′	99° 47′ 54.30′
Grey chicken	G	Guangyuan, Sichuan	30	1374 m	High	32° 38′ 52.48′	106° 05′ 46.36′
Chengkou mountainous chicken	CK	Chengkou, Chongqing	27	753 m	Middle	31° 56′ 51.92′	108° 39′ 50.76′
Jiuyuan chicken	JY	Taiping town, Sichuan	30	668 m	Middle	32° 04′ 01.40′	108° 02′ 13.92′
Pengxian yellow chicken	PY	Guihua town, Sichuan	30	643 m	Middle	31° 02′ 02.94′	103° 47′ 37.07′
Da ninghe chicken	DH	Wuxi, Chongqing	24	219 m	Low	31° 23′ 55.57′	109° 34′ 11.76′
Tassel first chicken	TF	Wulong, Chongqing	30	177 m	Low	29° 19′ 32.72′	107° 45′ 35.48′
Gushi chicken	GS	Gushi, Henan	26	54 m	Low	32° 11′ 22.25′	115° 40′ 18.79′
Wenchang chicken	WC	Wenchang, Hainan	29	17 m	Low	19° 44′ 27.63′	110° 46′ 21.40′

¹Original locations of the breeds. The determination of altitude, latitude and longitude using the sampling points as the criterion.