Assessment of pepper seed performance using desiccation sensitivity
Seed Science and Technology
Sch. of Agric. Sci. and Agribusiness, Crop Science Discipline, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, South Africa
During priming, seeds are subjected to hydration followed by dehydration and re-hydration is resumed during germination. It is postulated that the ability of seeds to withstand the effects of hydration and dehydration could be used to determine seed quality. Pepper (Capsicum annuum L.) seeds from different production seasons (1998, 2000 and 2002) were hydroprimed for 2 h and then desiccated for 72 h over saturated salt solutions at 12% RH (20°C), 33% RH (23°C) and 52% RH (23°C). Seed membrane integrity was determined by a comparison of desiccated seeds with non-desiccated seeds, with respect to cation (Ca2+, Mg2+, K+) content of steep water after imbibition. Seed desiccation sensitivity was determined by the total germination of desiccated seeds relative to control seeds that were neither hydrated nor desiccated over saturated salts. Desiccation sensitivity increased with the lowering of desiccation relative humidity. This effect was correlated with an increase in electrolyte leakage and reduction in seed germination, emergence and stand establishment. Fresh seeds were more resistant to desiccation than older seeds. A better correlation between desiccation sensitivity and seed quality compared with seed germination suggested that desiccation sensitivity could be used as a seed vigour test.