Effects of saline and alkali stress on seed germination of Delphinium grandiflorum

Seeds of Delphinium grandiflorum were treated by mixture solutions of four salts (NaCl, Na2SO4, NaHCO3 and Na2CO3) at different concentrations and two single salt of either NaCl or NaHCO3 to study effects of saline and alkali stress on seed germination of D.grandiflorum. Germination rate and germination index of the seeds, seedling biomass were also measured under saline and alkali treatments. The index of seed vigor was calculated according to the values measured before. The results showed that there was a beneficial for the accumulation of seedling biomass of D.grandiflorum at low concentrations of single NaCl threat. However, under mixture threats, the mixtures were detrimental to seed germination and seedling growth regardless their concentrations were high or low. Threat of the high concentration solution had a great influence on the seed vigor. When the concentration of the salt was up to 150 mmolL-1, the seed vigor was 0 under different treatments. There would be interaction between the salt threat and alkali threat, if both of them act on D.grandiflorum at the same time. They could affect the seed vigor together severely.