Imbibition temperature affects winterfat (Eurotia lanata (Pursh) Moq.) seed hydration and cold-hardiness response.

Abstract

Winterfat (Eurotia lanata (Pursh) Moq.) diaspores harvested from 1 Canadian and 2 USA sites were imbibed at 0, 5, 10, and 20 degrees C. It was hypothesized that imbibition temperature affects seed hydration which is related to cold-hardiness of winterfat. Weight gain was measured at 8-hour intervals until full hydration, and embryo water content was determined. Water content of fully hydrated seeds differed among collections and lower imbibition temperatures were always associated with greater seed water content. Differences in water content of seeds imbibed at different temperatures was related to cold-hardiness. When water content of embryos was measured, differences among imbibition temperatures existed, but were reduced. Differences in seed water content among imbibition temperatures were mainly due to endosperm other than the embryo because the embryo hydrated faster than other seed parts. Suggestions were made for modeling seed water relations based on this study.