Studies on the Media for Orchid Seed Germination

I. The Effects of Balances inside Each Cation and Anion Group for the Germination and Seedling Development of Bletilla striata Seeds

Abstract

The effects of balances inside each cation and anion group for aseptic culture of Bletilla striata seeds were examined, using a cation or anion triangle method.
Total concentration of the final nutrient media was held to 20 milligram equivalents per liter. To determine the optimal cationic balance, the nitrate, phosphate, and sulfate balance was held to the ratio of 40:10:50 percent of the anionic sum, and the magnesium level was kept at 10 or 30 percent of the cationic sum, but ammonium, potassium, and calcium were varied systematically. And to determine the optimal anionic balance, the ammonium, potassium, calcium, and magnesium balance was held to the ratio of 40:10:40:10 percent of the cationic sum, but nitrate, phosphate, and sulfate were varied systematically.
The optimal range of ions expressed in percent of total anion or cation concentration was obtained as follows;
NH₄⁺ 16-20 NO₃^- 66-88
K⁺ 35-41 H₂PO₄^- 7-23
Ca⁺⁺ 34-37 SO₄^-- 4-14
Mg⁺⁺ 10
One of the optimal nutrient compositions for the growth of Bletilla striata seeds was found to be;
Ca(NO₃)₂ 826mg/l Minor elements of Murashige and Skoog medium.
KNO₃ 747mg/l
NH₄H₂PO₄ 391mg/l Sucrose 20g/l
MgSO₄•7H₂O 172mg/l Agar 10g/l
Bletilla striata seeds did not require ammonium ions for germination, but their growth was stimulated by the presence of ammonium ions.