Recalcitrant and orthodoxSpartinaseeds or isolated embryos exhibit similar leachate patterns immediately following desiccation
AbstractSolute leakage is used as an indicator of membrane damage during desiccation of recalcitrant seeds. We re-examined this phenomenon and its utility by comparing recalcitrantSpartina alternifloraand orthodoxSpartina pectinataseeds, as well as drying isolated embryos or embryos isolated after whole-seed drying. During drying, intact seed leakage (electrical conductivity and absorbance at 280 nm) was independent of seed moisture content, dormant/non-dormant state or desiccation tolerance. Embryos from bothSpartinaspecies, isolated after drying within the intact seed, exhibited increased leakage, especially below 40% (dry weight basis, DWB) seed moisture, the critical water content for viability loss inSpartina alterniflora. When isolated embryos were dried, the pattern and extent of increased solute leakage were similar in bothSpartinaspecies, even thoughS. pectinataembryos were >95% viable andS. alternifloraembryos were < 20% viable. We conclude that increased solute leakage is an artefact of embryo excision and not an accurate indicator of desiccation damage to recalcitrantSpartina alternifloraseeds.