Figure 1.
Phenotype of spikes of cultivated and Tibetan wild barley genotypes.
Plants were affected by drought, salinity alone and combined stresses (D+S) during anthesis stage at 4% soil moisture level.
Figure 2.
The correlation between relative dry weight and ionic concentration.
The correlation between Na+, K+ concentration and Na+/K+ ratios and relative leaf (A, D and G), stem (B, E and H) and root (C, F and I) dry weight based on three genotypes: CM72, XZ16 and XZ5. ns’ not significant, * and ** indicate significant at 0.05 and 0.01, respectively.
Figure 3.
The antioxidant enzyme activities in cultivated and Tibetan wild barley genotypes.
Barley plants were exposed to alone and combined stresses of drought and salinity on superoxide dismutase (SOD, A) , peroxidase (POD, B), catalase (CAT, C) and ascorbate peroxidase (APX, D) in flag leaves of three barley genotypes during anthesis stage at 4% soil moisture level. Error bars represent SD values (n=4). Different letters indicate significant differences (P<0.05) among the treatments within each genotype. Control, drought, salinity and D+S correspond to normal growth condition without drought and salinity stress, drought stress (D, seedlings were subjected to drought stress for 20 d during anthesis by withholding irrigation until the soil moisture content (SMC) reduced to 4%), salinity stress (S, 1 L 200 mM NaCl solution was added per pot at anthesis stage and then kept humid throughout the experimental period), combined stresses of drought and salinity (D+S, 1 L 200 mM NaCl solution was added per pot at anthesis stage, then subjected to drought stress until SMC reduced to 4%), respectively.
Figure 4.
MDA content and CMSI in flag leaves of Tibetan wild and cultivated barley genotypes.
Barley plants were exposed to drought, salinity alone and combined stresses during anthesis stage at 4% soil moisture level. Error bars represent SD values (n=4). Different letters indicate significant differences (P<0.05) among the treatments within each genotype. CMSI, cell membrane stability index; MDA, malondialdehyde;.
Figure 5.
Glycine-betaine, soluble sugar, soluble protein and protease activity in flag leaves of three barley genotypes.
Tibetan wild and cultivated barley plants were exposed to drought, salinity alone and combined stresses during anthesis stage at 4% soil moisture level. Error bars represent SD values (n=4). Different letters indicate significant differences (P<0.05) among the treatments within each genotype.
Figure 6.
Reduced glutathione (GSH), reduced ascorbate (ASA) and total phenol (TP) contents in flag leaves of barley genotypes.
Tibetan wild and cultivated barley plants were exposed to drought, salinity alone and combined stresses during anthesis stage at 4% soil moisture level. Error bars represent SD values (n=4). Different letters indicate significant differences (P<0.05) among the treatments within each genotype.
Figure 7.
ATPase activity (µmol Pi mg−1 protein h−1) in flag leaves of three barley genotypes.
Tibetan wild and cultivated barley plants were exposed to drought, salinity alone and combined stresses during anthesis stage at 4% soil moisture level. Error bars represent SD values (n=4). Different letters indicate significant differences (P<0.05) among the treatments within each genotype.