The effects of temperature and salinity (NaCl) on germination of Hordeum maritimum With. (halophyte) and H. murinum L. (glycophyte) seeds were investigated. Dehulled caryopses were used for monthly germination trials, starting from November (120 days of after-ripening in darkness at 20±1°C). Trials were continued for one year. Differences in germination response between the two species were showed. It was confirmed H. maritimum is better adapted to high salinity levels and to variations in external temperature than H. murinum. H. maritimum showed a germination control mechanism related to after-ripening time and based on seed dormancy breaking/resumption. At high temperature (30°C), a thermodormancy was also observed. Germination strategies were not observed in H. murinum that is relatively insensitive to the combined effects of temperature and salinity. Thus, in H. murinum, in virtually all treatments, higher germination rate compared to H. maritimum, was observed as early as at 72h of culture, suggesting that dormancy, both in the absence and presence of salt, is totally depleted by the early fall or at latest in winter.
Seasonal changes in the germination responses of Hordeum maritimum and H. murinum seeds in relation to salinity, temperature and after-ripening time.
LOMBARDI, TIZIANA;ONNIS, ANTONINO
1999-01-01
Abstract
The effects of temperature and salinity (NaCl) on germination of Hordeum maritimum With. (halophyte) and H. murinum L. (glycophyte) seeds were investigated. Dehulled caryopses were used for monthly germination trials, starting from November (120 days of after-ripening in darkness at 20±1°C). Trials were continued for one year. Differences in germination response between the two species were showed. It was confirmed H. maritimum is better adapted to high salinity levels and to variations in external temperature than H. murinum. H. maritimum showed a germination control mechanism related to after-ripening time and based on seed dormancy breaking/resumption. At high temperature (30°C), a thermodormancy was also observed. Germination strategies were not observed in H. murinum that is relatively insensitive to the combined effects of temperature and salinity. Thus, in H. murinum, in virtually all treatments, higher germination rate compared to H. maritimum, was observed as early as at 72h of culture, suggesting that dormancy, both in the absence and presence of salt, is totally depleted by the early fall or at latest in winter.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
