Effects of salt stress on seed germination of grain amaranth in different germination substrates

Grain amaranth (Amaranthus hypochondriacus L.) is forage resources and with high quality and barrenresistant. In order to study the salt tolerance of seeds, this paper designed 5 salt stress treatments (0 g/kg 1 g/kg, 2 g/kg, 5 g/kg, 10 g/kg), conducted germination test in quartz sand substrate, saline-alkali soil substrate in Haixing and meadow cinnamon soil substrate in Anguo separately. The results showed that, in different substrates, grain amaranth germination rate and salt concentration showed a significant negative correlation, in quartz sand substrate, saline-alkali soil substrate in Haixing and meadow cinnamon soil substrate in Anguo, the regression equation slope of grain amaranth and salt concentration were -5.77, -8.787, -7.95. For the critical value of grain amaranth seed germination under salt stress, the saline-alkali soil in Haixing was larger than that of meadow cinnamon soil in Anguo, they were 3.5 g/kg and 3.4 g/kg, respectively; for the limit value under salt stress, the meadow cinnamon soil in Anguo was larger than that of saline-alkali soil in Haixing, they were 8.4 g/kg and 8.1 g/kg, respectively. Salt had certain inhibitory effect on the seed germination and seedling growth, with the salt concentration increasing, the seed germination rate decreased in the three kinds of substrates, seedling growth also showed the same trend.