Responses of Seed Germination and Seedling Growth ofCelosia argentea to Various Stresses

Utilizing Celosia argentea seeds as the experimental material, a hydroponic culture method was employed to examine the effects of 5 pH levels, 5 polyethylene glycol(PEG−6000) levels, and 5 NaCl levels on seed germination and seedling growth. The results indicated that 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 of PEG−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. The recovery percentage and dormancy percentage of non-germinated seeds 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. Radicle and hypocotyl length of seedling had great ecological plasticity, 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.