Responses of seed germination and seedling growth of Celosia argentea to acid, drought and NaCl stresses

Using by hydroponic method, Celosia argentea was utilised to investigate the response of seed germination and seedling growth to soil acidity, drought and NaCl stresses. Five pH levels(3, 3.5, 4, 5, 7), five PEG-6000 levels(0, 5, 10, 15 and 20%), and five NaCl levels(0, 50, 100, 150 and 200 mmol/L) were assessed, and to provide basic information for the application of C. argentea in soil restoration of paddy field transformed from dryland. The results indicated that: 1) Seed could germinate over the range of pH 3 to 5, and the germination percentage and germination potential were between 79% to 81% and 73% to 79% respectively, and significantly promoted seed in the early stage of germination. Germination percentage and seed potential decreased with increasing concentration ofPEG-6000, the seed germination was significantly inhibited only under high concentration(20%) PEG stress, but the germination percentage was more than 60%. The seed germination was not significantly inhibited under 50 mmol/L NaCl stress, and significantly inhibited under 100～200 mmol/L NaCl stresses. 2) The non-germinated seeds did not lose vitality under acid, drought and salt stress, recovery percentage and dormancy percentage increased significantly with increasing primary stress concentration, after 21 days, the number of accumulative seed germination were between 69% to 84%, high salt stress showed some iron toxic action. 3) Radicle and hypocotyl length of seedling had great ecological plasticity in acid, drought and salt stresses, the relationship between radical length, hypocotyl length and seedling height was a power function allometric scaling relationship, C.argentea adapted to the different environmental stresses by changing morphological traits. This study clarified seed germination and seedling growth strategy of C.argentea under different stresses, it was of strong acid-, drought-, and salt-tolerance and the capability coping with environmental changes, the results provided theoretical basis for soil restoration of Paddy field transformed from dryland.