Validity of Selection Breeding for High Ephedrine-Alkaloid Content in E. sinica under Different Environments in Japan.

Dried terrestrial stems of Ephedra sinica are called 'Ephedra herb,' whose pharmacological effects are due mainly to two major ingredients, (-)-ephedrine and (+)-pseudoephedrine (total alkaloids which are defined in Japanese Pharmacopoeia (TA)). Ephedra herb is an important crude drug in Japan. However, E. sinica is widely distributed in arid areas of northeastern China and Mongolia. Recently, E. sinica has started to be cultivated in Japan. This study aimed to assess the validity of selection breeding on TA content of E. sinica in several locations in Japan. In this experiment, we grew approximately 350 seedlings and divided them randomly into seven groups. Nearly fifty plants were cultivated at each of seven locations. In Ibaraki, Yamanashi, and Shizuoka, average TA content of whole samples satisfied the criteria for Ephedra herb defined in Japanese Pharmacopoeia (7.0 mg/g of dry weight (DW)). Plants with high and intermediate TA content at four locations were selected and transplanted to Ibaraki. There were significant differences in TA content between selected plants with high and intermediate TA content before and after transplanting (p < 0.05). TA content of high-TA plants was significantly higher than that of control plants cultivated continuously at Ibaraki (p < 0.05). These results suggest that the selection on content of ephedrine alkaloids in E. sinica under various locations in Japan is valid, and high- TA E. sinica plants can be selected at various locations.