Physiological and biological responses of wheat-rye substitution line seedlings to salt stress

The response of root activity, relative growth rate, water content, chlorophyll content and biomass allocation of the wheat-rye substitution line seedlings were investigated under different salt concentrations(0-250 mmol· L- 1NaCl). The results indicated that the root activity exhibited the trend of up- down with the increasing of the salt concentration. Under 100 and 150 mmol · L- 1salt concentrations, the root activity was higher than both the control and the salt treatments. Compared with the control, the values of the water content of aboveground were not significantly different, whereas these values were higher than those of the salt treatments when the salt concentration was no more than 100 mmol· L-1. There was no significant difference in the water content of underground, which suggested that the root retained the optimal ability of absorbing water. It was crucial for the plant to maintain the root activity and transport water up to the aboveground. With the prolongation time of the salt stress, the chlorophyll content increased. The relative growth rate of aboveground and underground was lower than the control when the salt concentration was surpassed 100 mmol · L- 1, indicating that the plant growth was inhibited under the salt stress. However, the root-canopy ratio and biomass allocation of the seedlings were not affected significantly under the salt stress. The results indicated that the resource allocation of the aboveground and underground were not affected under the salt stress. Overall, the seedlings of the substitution line had the endurance to the salt stress.