Development and optimization of a germination assay and long-term storage for Cannabis sativa pollen
Pollen viability and storage is of great interest to cannabis breeders and researchers to maintain desirable germplasm for future use in breeding or for biotechnological and gene editing applications. Here, we report a simple and efficient cryopreservation method for long-term storage of Cannabis sativa pollen. Additionally, we have deciphered the bicellular nature of cannabis pollen using DAPI staining. We have also standardized a pollen germination assay to assess the viability of cannabis pollen, and found pollen collected from different principal growth stages exhibits different longevity. Finally, we developed a long-term storage method which includes pollen combination with baked whole wheat flower and desiccation under vacuum for cryopreservation. By using this method, we were able to maintain germination viability in liquid nitrogen after 4 months, suggesting potentially indefinite preservation of cannabis pollen.