Determination of the most important characteristics in bread wheat grain yields under salinity stress

Abstract

Background Salinity has adverse effects on crop production in arid and semi-arid regions but so far, less attention has been paid to this impact on wheat characteristics. A pot experiment was carried out in cage-house to determine the most important characteristics in wheat under wide range of salinity using the stepwise regression analysis. The data collected on five groups of characteristics (i.e. seedling, phonology, spike, physiology, yield and its contributions). Results The findings showed that the salinity levels below 3.5 dSm− 1 triggered stimulation in the growth of wheat seedling, while the salinity rates increased by more than 3.5 dSm− 1 significantly reduced all the seedling characteristics studied. The salinity level of 3.5 dS m− 1 resulted in an earliness percentage of 4.2, 4.9, 3.8 and 2.2% respectively in the developmental stages of booting, heading, anthesis and maturity. Meanwhile, rising salinity levels up to 10.5 dSm− 1 resulted in a 21.7% decrease in emergence speed and a delay of 3.9, 10.8 and 8.5% in booting, heading and anthesis developmental stages respectively. Salinity stress decreased the flag leaf area and increased concentration of chlorophyll pigments, where the percentage increase for chlorophyll a was higher compared with chlorophyll b and total chlorophyll. The stress of salinity decreased all the studied spike characteristics with significant effect on the number of spike− 1 and spike kernel weights. Conclusions Salinity stress decreased yield and other contributes where its effect was strong on plant height, root dry weight, biological and grain yield. The stepwise regression showed that biological yield, spike kernels weight and number of spikes pot− 1 characteristics under both normal and salinity stress are the important selection criteria of high grain yield.