Dehydration Effects on Imbibitional Leakage from Desiccation-Sensitive Seeds

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Abstract
Changes in electrolyte leakage and viability in response to dehydration stress were examined in 2 spp. of seeds that do not survive desiccation. Leakage from silver maple (Acer saccharinum L.) seeds increased markedly as seed moisture contents decreased from 45 to 35% (fresh weight basis) and germination decreased from 97 to 5%, coincidentally. Time course curves of imbibitional leakage from areca palm (Chrysalidocarpus lutescens [Bory] Wendl.) embryos increased initial leakage and steady-state leakage rates in response to dehydration from an original moisture content of 84 to as low as 53%. Absorbance at 530 nm of extracts from triphenyl tetrazolium chloride-stained embryos of areca palm was used as a measure of viability. Absorbance decreased significantly in response to dehydration as embryo moisture content decreased from 80 to 30%. Apparently membranes in the desiccation-sensitive seed tissues studied are damaged by dehydration below a critical moisture content, 40% in silver maple seed and 55% in areca palm embryos, and the membrane damage contributes to loss of viability.