Seedbed ecology of winterfat: effects of mother-plant transpiration, wind stress, and nutrition on seedling vigor

Abstract

The upward movement of absorbed salts within a plant is influenced by the transpiration stream. This study tested the hypothesis that transpiration by winterfat mother plants affects seedling vigor. Mature plants, growing in a greenhouse, were exposed to forced air and measurements were made on water loss from the plants, concentrations of Ca++, Mg++, Na+, and K+ in the diaspores, and on offspring growth parameters. The diaspores produced by the plants were germinated and grown under 2 identical temperature regimes, except that 1 regime included 1 hour of dark-period freezing stress. The forced-air treatment had no detectable effect on mother plants, including no significant (P less than or equal to 0.05) effect on water loss or on cation concentrations in the diaspore. However, it did significantly decrease offspring vigor. Analysis of the total test-plant population revealed significant, linear relationships between water loss and: diaspore yield, Ca++ and K+ concentrations in the diaspore, seedling dry weight, and seedling hypocotyl length. Linear relationships between seedling variables and covariables provided evidence that Ca++, K+ and Na+ influence seedling weight, moisture, and hypocotyl length. It is concluded that mother-plant transpiration, windstress, and nutrition affect offspring vigor.