Germination and dormancy breaking by ethephon in mature and immature seeds of Medicago truncatula (medic) and Trifolium subterraneum (clover)

Abstract

The effects of ethephon (2-chloroethylphosphoric acid) and temperature on seed germination were studied in two cultivars of Medicago truncatula (medic) and one cultivar of Trifolium subterraneum (clover) grown under different controlled conditions. Ethephon promoted germination of immature and fresh mature seeds and increased the germination rate of old mature seeds. Ethephon thiourea and carbon dioxide had different effects on the germination of seeds of the medic cultivars. At 30°C, untreated seeds germinated poorly while the presence of 10 ppm ethephon increased germination significantly.