Effect of Gibberellin Treatment on Growth and Flowering Characteristics in the Cultivation of Aquilegia japonica Nakai & H. Hara

This study was conducted to develop gibberellin treatment technique to enhance flower initiation in Aquilegiajaponica Nakai & H. Hara. Seedlings were planted in 12㎝-diameter pots on October 2016 and grown in green house. Ambient temperature in the green house was set at minimum 15℃ during day and night to suppress flower initiation at coldtemperature condition. Two different types of gibberellin, GA3 and GA4+7, at 4 different concentration levels 100, 200, 400and 600 ㎎/L, were tested in this study. Gibberellin was sprayed first at planting and secondly at 1-week after planting. Tento fifteen ㎖ of gibberellin was sprayed for each pot. Plant height and petiole length were elongated by both gibberellintypes, flowering was more enhanced by GA3 (91.7∼100%) compared to of GA4+7. However, abnormal flower was lessobserved in GA3 treatment (0∼16.7%) than GA4+7. Number of flower stalks per plant ranged from 1.9 to 2.5. Number offlowers per plant ranged from 6.8 to 10.3. Differences in flowering characteristics between treatments were statisticallysignificant. Optimal gibberellin treatment to enhance flower initiation in A. japonica Nakai & H. Hara substituting coldtreatment was GA3 at the concentration between 400 ㎎/L to 600 ㎎/L.