Table 1.

Effects of preserved pollen on off-site pollination in Beijing.

Female parent		Male parent			Pre-treatment of flowers	Number of plants	True hybrid number	True hybrid rate (%)
Variety	Site	Variety	Pollen collection site	Pollen collection date
Zhonghuang39	Beijing	Heihe43	Heihe	15th July	Dehydrated for 10 h	30	27	84.4
Zhonghuang39	Beijing	Heihe43	Heihe	15th July	Dehydrated for 14 h	15	14	93.3
Zhonghuang39	Beijing	Zhonghuang30	Beijing	21st August to 25th August	No (fresh)	5	3	60.0

On 15 July 2020, pollen of Heihe 43 at the initially-open stage was collected, dehydrated, frozen in LN for 72 h, and then stored at −80°C. On 16 August 2020, the package was sent to Beijing by express delivery. From 21–25 August 2020, hybridization verification tests were carried out in Beijing using the preserved pollen sent from Heihe by express delivery.