The recently domesticated species, Cephalaria joppensis (CJ), is emerging as a new alternative forage crop in Israel. It has high biomass potential and nutritional values that are comparable to forage wheat. However, ...The recently domesticated species, Cephalaria joppensis (CJ), is emerging as a new alternative forage crop in Israel. It has high biomass potential and nutritional values that are comparable to forage wheat. However, CJ emerges slowly under cold conditions, which hinders its development as a major winter crop. Additional tolerance for abiotic stress would improve its performance as a forage crop. We examined the effects of several abiotic factors (i.e., cold, salinity, drought and pH) on CJ germination under controlled conditions. The effect of temperature was studied by incubating seeds at different temperatures between 7°C and 35°C. The effects of salinity, osmotic potential and pH were tested by incubating seeds at different NaCl, PEG and pH levels, respectively. Temperature, salinity and osmotic potential significantly affected germination;whereas pH did not. Temperature did not affect the final proportion of germinated seeds, but did affect other germination-rate variables, indicating that germination rate might be the limiting factor under field conditions. Salinity also affected germination-rate variables, but not the proportion of seeds that germinated. Notably, CJ was found to be relatively resistant to high salt concentrations, with a 273 mM NaCl threshold for germination, indicating its potential as a relatively salt-tolerant forage crop. Both the proportion of germinated seeds and the germination rate were highly sensitive to the osmotic-potential treatments, indicating that drought resistance will remain the biggest challenge for CJ. This study provides baseline data for a rapid and efficient system for further screening for abiotic-stress tolerance among wild and cultivated lines of CJ.展开更多
文摘The recently domesticated species, Cephalaria joppensis (CJ), is emerging as a new alternative forage crop in Israel. It has high biomass potential and nutritional values that are comparable to forage wheat. However, CJ emerges slowly under cold conditions, which hinders its development as a major winter crop. Additional tolerance for abiotic stress would improve its performance as a forage crop. We examined the effects of several abiotic factors (i.e., cold, salinity, drought and pH) on CJ germination under controlled conditions. The effect of temperature was studied by incubating seeds at different temperatures between 7°C and 35°C. The effects of salinity, osmotic potential and pH were tested by incubating seeds at different NaCl, PEG and pH levels, respectively. Temperature, salinity and osmotic potential significantly affected germination;whereas pH did not. Temperature did not affect the final proportion of germinated seeds, but did affect other germination-rate variables, indicating that germination rate might be the limiting factor under field conditions. Salinity also affected germination-rate variables, but not the proportion of seeds that germinated. Notably, CJ was found to be relatively resistant to high salt concentrations, with a 273 mM NaCl threshold for germination, indicating its potential as a relatively salt-tolerant forage crop. Both the proportion of germinated seeds and the germination rate were highly sensitive to the osmotic-potential treatments, indicating that drought resistance will remain the biggest challenge for CJ. This study provides baseline data for a rapid and efficient system for further screening for abiotic-stress tolerance among wild and cultivated lines of CJ.
