Advanced seed invigoration techniques enhance germination performance of Trifolium species under salinity and drought stress

Abstract

An experiment was carried out to evaluate the response of primed and unprimed seeds of red clover (Trifolium pratense) and white clover (T. repens) to drought and salinity stress during early seedling development. The study demonstrated that both stress conditions delayed seed germination in all treatments; however, primed seeds exhibited a comparatively enhanced germination response under both drought and salt stress compared to unprimed seeds. Key germination parameters, including germination percentage (G%), speed of germination (SG), seedling length, and vigour index, were notably higher under salt stress (NaCl) than under drought conditions simulated with polyethylene glycol (PEG), in both clover species. This indicates that salinity stress had a less severe impact on early seedling growth than drought stress. Hydropriming significantly reduced the mean germination time (MGT) and enhanced the SG, G%, and vigour index across all stress treatments relative to the control, suggesting its potential as an effective strategy to enhance stress tolerance in clover species during the germination stage.