カルシウムとマグネシウム処理がキクの生長, 栄養成分含量, エチレン生成と内生ジベレリン含量に及ぼす影響

Effects of calcium (Ca) and magnesium (Mg) treatments on growth, nutrient contents, ethylene evolution, and gibberellin (GA) content of Dendranthema grandiflora (Ramat.) Kitam. were investigated. Treatments were as follows (per pot): 0.0 g Ca or Mg (Control), 0.2 g Ca, 0.5 g Ca, 0.2 g Ca+0.2 g Mg, 0.5 g Ca+0.2 g Mg, and 0.2 g Mg. Plant height increased significantly in 0.5 g Ca and 0.5 g Ca+0.2 g Mg treatments but not in other treatments. Shoot dry weight increased in all the treatments except in 0.2 g Mg treatment compared with the control. N content decreased in Ca+Mg and Mg treatments, whereas K content increased in all treatments compared with the control. Ca content increased in 0.2 g Ca and 0.5 g Ca treatments but decreased in 0.2 g Mg treatment; Mg content increased in Ca+Mg and Mg treatments. All treatments reduced ethylene evolution rate faster than the control for 10 days. Total GA-like substances increased in plant treated with 0.5 g Ca+0.2 g Mg. GA-like substances were found in the HPLC fractions 3, 7, 8, and 12 in control plants. GA1- and GA3-like substance contents did not change in 0.2 g Ca, 0.5 g Ca or 0.2 g Mg treated plants but decreased in Ca+Mg treated plants compared with the control. Thus, Ca and Mg treatments affect not only the growth of chrysanthemum plants and nutrient contents but also GA activities and ethylene evolution.