Slow drying improved desiccation tolerance of immature seeds of common vetch

Abstract

Drying common vetch seeds in the intact pods improved their desiccation tolerance and germination, this may be due to a slower rate of seed moisture loss or additional gain of dry weight of the seeds. Little information is available on the effect of slow drying on the desiccation tolerance of immature seeds of common vetch. The objective of this experiment was to study the effect of seed incubation at 100% relative humidity for 48 h on the rate of moisture loss and germination of common vetch seeds harvested at different maturity stages. Seeds were harvested at five pod developmental stages; 1) beginning seed fill (BS), 2) full-size seed (FS), greenishyellow, 4) yellow pod and 5) brown pod. Harvested seeds were subjected to two drying methods; either dried under ambient condition or by incubating the seeds at 100% relative humidity for 48 h prior to drying under the ambient condition. Incubating the seeds at 100% RH reduced the rate of seed moisture loss and enhanced the germination of the immature seeds (the FS and GY stages). These results emphasized the importance of the slow drying for enhancing seed desiccation tolerance during seed development and maturation of common vetch, demonstrating that the germination ability of common vetch was independent of seed mass and maturation.