Most recently, he visited ARS cytologist William P. Wergin in Beltsville, Maryland, to look at the seeds through a scanning electron microscope specially designed to view frozen tissue. Booth soaked and froze the seeds to simulate the West's freeze-thaw cycles. Particularly in the spring, seeds often get wet from snowmelt during the day and then, overnight, the water in the seeds turns to ice crystals. Or the seeds get wet and start sprouting during a warm spell, only to be frozen by winterlike spring storms. Booth, working with Yuguang Bai, who is with Agriculture and Agri-Food Canada in Kamloops, British Columbia, and Jim Romo, with the University of Saskatchewan, found that water absorption before germination is greatest for seeds soaked at 40 o F or lower.
Most seeds have a greater risk of freezing damage as their water content increases.
Winterfat, however, often grew better when it had been soaked at cold temperatures before freezing. Seedling vigor also varied by where the seeds were collected, indicating that the plants have evolved so that the germination requirements of the seeds fit local climate variations. F before being plunged into and stored in liquid nitrogen to preserve any internal ice crystals, as well as nearby tissue. What surprised him was that the tissue was freeze-dried, with only occasional large ice crystals and no indication of normal cellular structure. That intrigues Booth because of his suspicion that winterfat may fight ice with ice.