Comparison of germination responses of cultivated wheat ( Triticum ) and its wild relative ( Aegilops ) species under salinity, temperature and light

Abstract

The seed germination of bread ( Triticum aestivum cv. Bezostaya 1 and Ceyhan 99) and durum ( Triticum durum cv. Diyarbakır 81 and Fırat 93) wheat species and their wild relative species ( Aegilops biuncialis and Ae. triuncialis ) was compared at two light levels, nine NaCl concentrations and three alternating temperature regimes. No seeds germinated at 675 mmol/L NaCl. The highest seed germination (100%) of cultivated wheat cultivars was noted in the control at 15/25°C and 20/30°C, and that of wild wheat species in both the control and the 150 mmol/L NaCl treatment under all temperature regimes. The seed germination of bread and durum wheat cultivars was completely inhibited at or above 450 and 375 mmol/L NaCl, respectively. No Ae. biuncialis seeds germinated at 600 mmol/L NaCl, while seeds of Ae. triuncialis germinated at this concentration (38.9%) only at 20/30°C in darkness. The inhibitory effect of light on germination in all genotypes was determined in some salinity levels at 15/25°C. The optimal germination treatment for all genotypes was 15/25°C temperature regime and darkness. The inhibitory effect of high salinity on germination was greater at 25/35°C than at 15/25°C or 20/30°C. In salinity and temperature interactions, the seeds of wild wheat species were found to be more tolerant than those of wheat cultivars.