Effects of salt and alkali stress onReaumuria soongorica germination

摘要

Seed germination and early seedling growth are crucial stages for plant establishment. Two neutral (NaCl and Na2SO4) and two alkali (NaHCO3 and Na2CO3) salts were selected to investigate their effects on germination and recovery responses in Reaumuria soongorica. Results show that both salt types significantly reduced germination and radicle elongation. The rate of germination and emergence of R. soongorica seeds continuously decreased as salinity increased, and the time to achieve maximum germination rate was delayed. The speed of seed germination dropped rapidly as salt concentration increased. Alkaline salts restricted the germination rate ofR. soongorica seeds, and stresses resulting from alkaline salts and high concentrations of neutral salts resulted in many deformed seedlings. The length of the radicle and germ decreased with in-creasing salt concentration, but certain concentrations of salt and increased pH promoted germ growth. The results of re-gression analysis show that salt concentration was the dominant factor inhibitingR. soongorica seed germination rate. Sa-linity, buffering capacity, and pH all affected embryo growth, but salinity had the most pronounced effect. Seed viability under highly saline conditions appears to be a better indicator of adaptation to saline environments than seed germination under saline conditions.