Proline and agronomic production responses of different barley cultivars to salinity stress: A correlation analysis

Salinity affects crop growth and development, and markedly leads to observable losses in agronomic yield. Barley is considered as an excellent model crop for the prediction of crop response to climate change and as a salt tolerance crop. The main objective of this study was to identify the correlation magnitude (r) between salt stress level and both agronomic parameters and proline accumulation in barley leaves. Twenty-eight barley genotypes were exposed to salt stress, ranging from 0.85 to 16 dS/m. This simple approach will help agronomist and farmers to predict plant response under different soil salinity levels. The following agronomic parameters were recorded: proline accumulation (mg/kg), plant height (cm), grain yield (g/plant), harvest index (%), biological yield (g/plant) and straw yield (g/plant). For the purpose of data fitting and simplicity, a simple linear regression analysis was used. The results of this study showed that agronomic parameters in barley had moderate to strong correlation coefficients ranging from 0.67 to 0.98. Reduction rates in agronomic parameters were 0.799 cm, 0.079 g/plant, 0.007%, 0.67 g/plant and 0.036 g/plant per one dS/m increment of salt stress on plant height, grain yield, harvest index (%), biological yield and straw yield, respectively. This study also showed that per one unit increase of water salinity, proline accumulation increased by 1.49 mg/kg. It can be concluded from this study and under the current growing conditions, agronomic parameters and proline accumulation in examined barley genotypes are well correlated with increasing the level of salt stress.