Potential of the electrical conductivity of seed soak water and early counts of radicle emergence to assess seed quality in some native species

The potential of the electrical conductivity (EC) test to predict final germination was evaluated in seed lots from seven native species. In four of the seven species tested (Cyanus segetum, Prunella vulgaris, Valeriana officinalis and Centaurea nigra), EC was indicative of the final germination (radicle emergence; RE), with high levels of leakage seen for lots with low germination. Single seed measurements of solute leakage from two species confirmed the link between high leakage and the failure to germinate, while in Cyanus segetum, high EC was also associated with slow germination (after 42 hours). Reduced EC and earlier RE following a pre-hydration treatment in C. segetum supported the hypothesis that metabolic repair may occur during early imbibition. A single early count of RE (at 42 hours) also predicted germination (R-2 >= 0.858) for 12 seed lots of C. segetum. Therefore, both measurements of solute leakage from seeds using EC and early counts of RE have potential to predict the germination of seed lots from native species. The use of the EC test may be dependent on the structure of the seed, but the RE test may be applicable to a wider range of species and predict both germination and vigour differences.