Response of Wheat Varieties from Semi-arid Regions of Jordan to Salt Stress

This study was carried out to determine the effects of salinity levels (control, 6, 12 and 18 dS m(-1)) on germination, seedling growth, some agronomic traits and proline accumulation in leaves of nine wheat varieties adapted to semi-arid areas of Jordan. The tested wheat materials included eight durum wheat varieties (Haurani 27, Acsad 65, Om Rabbeeh, Sham 1, Safra Ma'an, Katma, Al-Samra and F8) and one bread wheat variety (Diel Harthon). Final germination percentage, shoot and seminal root length, and all growth and yield parameters were significantly (P < 0.05) decreased by increasing salinity level. Proline content was significantly (P < 0.05) increased by increasing salinity. There were significant variety x salt interactions (P < 0.05) on final germination percentage, seminal root length, grain yield and yield-related traits indicating that the varieties responded to salt differently. Sham 1 did not show any decrease in germination ability at the different salinity levels. Haurani 27, Acsad 65, Al-Samra and Diel Harthon showed a nonsignificant reduction in germination potential at low and intermediate salt levels. Safra Ma'an and Al-Samra showed the lowest reduction in seminal root length at low salt level and consequently exhibited the lowest stress susceptibility index 'S' values. Grain yield-based stress susceptibility index 'S' indicated that Haurani 27, Acsad 65, Katma, Al-Samra, F8 and Diel Jardoon were more salt tolerant than Om Rabbeeh, Sham 1 and Safra Ma'an. In conclusion, a similar salt tolerance was observed at different growth stages in Haurani 27, Acsad 65 and Al-Samra. Consequently, these three varieties could be considered as salt tolerant and accordingly they are suitable for durum wheat improvement. Furthermore, Sham 1 had the highest ability to germinate at high salinity level indicating that it has a genetic potential for salt tolerance, at least at this stage of its life cycle.