培養液のイオン組成がドリテノプシスの乾物重と成分組成に及ぼす影響(土壌管理・施肥・灌水)  [in Japanese] Effects of the Ionic Composition of Nutrient Solutions on the Dry Weight and the Chemical Content of Doritaenopsis(Soil Management, Fertilization & Irrigation)  [in Japanese]

ミズゴケで栽培したドリテノプシスの乾物重と成分含有率に及ぼす培養液のイオン組成の影響について検討した.茎葉,根,花序などの乾物重と乾物割合は,処理区間での差は比較的少なかった.しかし,K^+濃度の増加は茎葉の乾物重の増加に,Ca^<2+>濃度の増加は減少につながった.乾物率は器官間での違いが大きく,茎葉部では6.4〜7.4%であったのに対し,根部は8.5〜10.4%,花序部では7.0〜8.4%となった.各成分の含有率は培養液中の特定のイオン比率が上昇すれば同種元素含有率は増加したが,陽イオンあるいは陰イオン群内の他種のイオンの吸収は抑制された.本実験の陽イオン処理区では茎葉のCa含有率,花序のP含有率に違いが見られた.また,陰イオン処理区では根のP,Ca含有率,花序のN,Ca含有率に違いが見られた.これは,各イオンの吸収と移動が,培養液組成によって影響を受けたことによるものと考えられた.K^+はH_2PO_4^-の吸収・転流を阻害し,NO_3^-はCa^<2+>の吸収を促進したが,その機作については不明であった.

Effects of the ionic composition of nutrient solutions on the dry weight and the chemical contents of Doritaenopsis plant potted by sphagnum moss were investigated. Dry weight of shoot, root, inflorescence and these dry weight ratios were relatively constant in different treatment. However, increase of K^+ levels increased shoot dry weight, while that of Ca^<2+> levels had a reverse effect. Dry weight ratios showed large difference among different organs. The values were 6-7%, 9-10%, and 7-8% in shoot, root, and inflorescence, respectively. Mineral content increased corresponding the increase in mineral ions in the nutrient solution, but the absorption of the other ions were inhibited antagonistically in the same ion group, i.e. in cations or anions. In cationic treatments, significant differences of Ca and P concentrations in the shoot were observed. In anionic treatments, significant differences in P and Ca concentrations in the root and N and Ca concentrations in the inflorescence were observed. These differences indicated that absorption and translocation of each ion was affected by composition of the nutrient solution. K^+ inhibited H_2PO_4^- absorption and the translocation and NO_3^- accelerated Ca^<2+> absorption but the mechanism was not clear.