A simple pollen collection, dehydration, and long-term storage method for litchi (Litchi chinensis Sonn.)

•A simple pollen collection, dehydration, and storage method for litchi was found.•Anthers between the second stage to the third stage were collected.•Anthers were dried with an electric air-blowing dryer at 35 °C for 6 h.•The pollen collected was stored at −86 °C for long-term preservation.

A simple method for pollen collection and storage was devised for three litchi cultivars, namely, ‘Sanyuehong,’ ‘Shuidong,’ and ‘Guiwei’. This method could realize long-term pollen storage over periods of up to two years for artificial pollination and crossbreeding. The most suitable drying method for litchi pollen was the use of an air-blowing electric dryer at 35 °C for 6 h. The germination rate of pollen stored at different temperatures (30 °C, 25 °C, 15 °C, 4 °C, and −86 °C) was investigated. The pollen germination rate decreased to lower than 5% after 9, 16, 27, and 52 d at 30 °C, 25 °C, 15 °C, and 4 °C, respectively. A significant negative correlation was observed between pollen germination rate and storage time. For all litchi cultivars tested, pollen cryo-stored (−86 °C) for one year showed significantly higher germination rates than those stored under the other conditions. Pollen stored at −86 °C maintained a high germination rate of above 70% even after two years of storage. Thus, our results indicated that storage of pollen at 4 °C was suitable for field pollinations in the blooming season for up to two months. However, storage at −86 °C maintained the high germination rates required for artificial hybridization even in the second year of storage.