Background : This study was conducted to investigate the seedling, growth, and yield characteristics of 1-year-old Polygala tenuifolia by cultivation of different regions.
Methods and Results : After growing the seedlings for 2 months in the greenhouse, they were planted at different altitudes including: 100 m or less (Cheongju), 250 m (negative), 300 m (Jecheon), and 500 m (Pyeongchang) in the first week of May. The flowering period, fertilization period, fruit weight, growth, and yield were recorded and investigated in that period. Results of analyzing the physicochemical properties of the soils revealed that the pH of the soil was close to neutrality of 6.7 - 7.3 at 100 m, 250 m, and 500 m altitudes and an acidity of pH 5.7 at 300 m altitude. The average temperature for different time periods and altitudes are the following: 3.8℃ from June to October during the harvesting season, 21.8℃ at 100 m altitude in the end of June, 10.8℃ at 500 m altitude in the middle of harvest period, and 2.7℃ higher at 100 m altitude than 500 m altitude. The difference in the number of rooting (between 11 and 12/㎡) and the rate of rooting (82 - 92%) was not significant. The plant length was 25 - 26.5 ㎝ at 300 m and 500 m altitude. The largest number of branch was at 1.8 with 250 m altitude and largest stalk diameter at 500 m altitude at 6.0 ㎜. Leaf length and leaf width were the same per area, but the branches were the largest at 500 m at 17.9. Dry weight of 12.7 g was heaviest at 500 m altitude implying that the higher the altitude, the higher the dry weight will be. Moreover, in the 500 m altitude, root length of 29.2 ㎝ was the longest, root diameter was 5.9 ㎜, and the dry root weight of 7.9 g was the heaviest. However, the number of supporting root was 4.9 - 7.3 which was not statistically significant. The optimal yield per 10 a was 94 ㎏ at 500 m altitude. This was very high compared to yield of 28 ㎏ at 100 m altitude. The seed weight per 10 a was 1.5 ㎏ and 2.3 ㎏ at 100 m and 300 m altitude, respectively. The highest content of Teuifolin contained in the root was 124.07 ppm at 500 m altitude.
Conclusion : Results showed that 1-year-old P. tenuifolia had optimal growth, higher yield and better vital component content at altitude of 500 m.