AUTHOR=Jia Hongchang , Liang Xin , Zhang Lixin , Zhang Jinmei , Sapey Enoch , Liu Xianyuan , Sun Yanhui , Sun Shi , Yan Hongrui , Lu Wencheng , Han Tianfu TITLE=Improving Ultra-Low Temperature Preservation Technologies of Soybean Pollen for Off-Season and Off-Site Hybridization JOURNAL=Frontiers in Plant Science VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.920522 DOI=10.3389/fpls.2022.920522 ISSN=1664-462X ABSTRACT=

Preserving viable pollen is of great interest to breeders to maintain desirable germplasm for future inbreeding. Ultra-low temperature preservation of pollen is an effective and safe way for long-term storage of plant germplasm resources. In this study, we improved methods for the preservation of soybean pollen at ultra-low temperature. Soybean flowers at the initially-open stage were collected at 6–10 a.m. during the fully-bloom stage of soybean plants and were dehydrated for 10 h and then frozen and stored at −196 or −80°C. In vitro culture experiments showed that the viability of preserved pollen remained as high as about 90%. The off-season (local site Heihe) and off-site (Beijing, after long-distance express delivery from Heihe) hybridization verification was conducted, and no significant difference in true hybrid rate was founded between the preserved pollen and the fresh pollen. The ultra-low temperature preservation technology for soybean pollen could break the spatiotemporal limit of soybean hybridization and facilitate the development of engineered soybean breeding.