Table 1. Environmental information for the origin of the varieties.

Group	Declaration of origin	Altitude (m)	Latitude (°)	Longitude (°)	Mean annual temperatures (°C)	Mean annual precipitation (mm)
SC	Deyang city, Sichuan Province	784	31.01	105	16.7	883
YN	Mile city, Yunnan Province	1,792	24.59	103.62	17.3	987.5
SX	Tongguan city, Shanxi Province	330	34.62	110.18	12.8	625.5
HN	Sanmenxia city, Henan Province	673	32.61	111.96	12.5	848

Note:

Abbreviations for the four varieties are as follows: SC, Sichuan; SX, Shanxi; YN, Yunnan; and HN, Henan.