Researchers have developed a way to determine the viability of pollen germination in marijuana plants, as well as a simple method of storing cannabis pollen for long periods of time, according to a new study.
For marijuana cultivators, the results could prove useful, helping them avoid potentially costly mistakes in the process and ensuring consistency and quality in their crops across growing cycles.
Ensuring long-term storage of pollen is important for cultivators because of the central role it plays in generating seeds. Taking pollen from a male plant and rubbing it on the hairs of a female plant—typically about halfway through the flowering cycle—will enable the female plant to produce buds that contains seeds, which along with cloning is one way to propagate and maintain strains.
The study, which was partly funded by the Canadian government, has “several implications,” co-author Igor Kovalchuk told Marijuana Moment.
First, the team created an “assay to test viability of such pollen before the use for pollination.”
They accomplished that by modifying an existing method of assessing germination viability, using a liquid media instead of a solid medium, which “resulted in better image acquisition and quantification of germination,” according to the study.
Perhaps even more consequential for growers, however, is the development of a long-term storage system for cannabis pollen.
“We have provided an easy protocol for cryopreservation using desiccation combined with baked wheat flour and subsequent long-term storage of cannabis pollen in liquid nitrogen.”
“This one is big,” Kovalchuk said. “Our protocol allows nearly indefinite storage,” which is “valuable for maintaining large collection of genetics.”
To preserve the pollen, the researchers removed any moisture, added the result to baked whole wheat flour and preserving agents and then froze it in liquid nitrogen. When they removed the mixture from the liquid nitrogen and applied it to flowering female plants, it resulted in successful seed formation in all of the subjects.
“By using this method, we were able to maintain germination viability in liquid nitrogen after 4 months, suggesting potentially indefinite preservation of cannabis pollen.”
The team also discovered that pollen can be more or less viable at different stages of the flowering period. The optimal time to extract pollen seems to be during the mid-flowering stage. At that point, it retained “viability the longest with 22 percent of pollen grains successfully germinating after 21 days” of storage in a low-temperature environment.
“In conclusion, we have standardized a simple assay for quickly assessing pollen germination in Cannabis sativa,” the study states. “By using our [modified assay], we have demonstrated the loss of pollen viability over time when stored at 4 degrees Celsius, and suggested an optimal time during flower development for pollen collection to maximize longevity during storage.”
“Finally, we have provided an easy protocol for cryopreservation using desiccation combined with baked wheat flour and subsequent long-term storage of cannabis pollen in liquid nitrogen,” it concludes.
Photo by davide ragusa on Unsplash.