2018 ASHS Annual Conference

Lonicera subsessilis Rehder, which belongs to the Caprifoliaceae, is located in the Baekdudaegan area, ranging from Pyeongangnam-do to Jeollanam-do in the Korean peninsula. L. subsessilis is generally known to grow up to 2 meters tall, has high density of the branches, and the rich green leaves and the autumn ripe fruit is attractive. So they are highly valuable for ornamental purposes. In order to utilize the L. subsessilis, a sufficient quantity of materials should be supplied to ensure their stability. This experiment was carried out with the goal for developing mass production protocol. The seeds used in the experiment were collected from plants growing the Korea National Arboretum in Pocheon on May 26, 2017. The seeds were sown in field soil in an experimental garden. Every 2 weeks, seeds were exhumed, and phenology of embryo growth, germination, and seedling emergence was observed. Temperature requirements for germination were also determined by incubating seeds under controlled laboratory conditions. As a result of the imbibition experiment, seed fresh weight increased by approximately 91.3% over the previous 24 hours. At the time of seed disposal, L. subsessilis has underdeveloped embryo (about 11.3% of seed length). In seeds incubated at 5, 15, 20, and 25℃, germination percentage was 0, 80.0, 85.6, and 76.7% at 27 weeks after sowing, respectively. Most of the seeds incubated at 15 and 20℃ germinated within 12 weeks, whereas the seeds incubated at 25 germinated within 25℃ weeks. In the move-along test [summer start: 25 (12 wk) → 20 (4 wk) → 15 (4 wk) → 5℃ (12 wk) or winter start: 5 (12wk) → 15 (4 wk) → 20°C (4 wk) → 25℃ (12 wk)], summer and winter start seeds started to germinate at 15 and 25 weeks after sowing, respectively. And the final germination rate for each treatment was 83.3% at 17 weeks, and 83.3% at 30 weeks, respectively. The result indicates that germination was promoted at a relatively warm temperature (15-20℃). Therefore, the seeds expressed non-deep simple morphophysiological dormancy (MPD).