2018 ASHS Annual Conference

Iris laevigata Fisch., which belongs to the Iridaceae, is a perennial plant native to Korea, China, Japan, and Russia, grows in the mud of a pond, stream, or river bank. Purple flowers, which are about 12cm in diameter, are highly valued in May and June. However, it is now designated as a "Data Deficient" (DD) grade (Korea Forest Service) because it does not have many natural sites known for its reckless development and damage to its natural habitats. Preservation and reproduction and further development into coronary plants require the development of reproductive methods. This study was carried out to determine the dormancy type of I. laevigata seeds and to establish the germination conditions to restore the native habitat of the I. laevigata and to preserve its status outside of its current habitat. Temperature requirements for embryo growth and germination were determined by incubating seeds under controlled laboratory conditions. The seeds had underdeveloped embryos, which had grown to about 55% of those of fully matured seed before germination. When tested at the time of dispersal, seeds did not germinate during 16 weeks of without chilling treatment. Therefore, the seed dormancy type for I. laevigata was morphophysiological. In the controlled laboratory experiment, after cold stratification at 5℃ for 0, 4, 8, or 12 weeks, the seeds germinated to 0, 11.7, 43.4, or 51.7%, respectively, after 2 weeks of incubation at 25℃. After warm (25℃, 8 weeks) followed by cold stratification for 0, 4, 8, or 12 weeks, the seeds germinated to 0, 51.7, 85.0, or 88.3%, respectively, after 2 weeks of incubation at 25℃. Additionally, GA₃ treatment did not overcome the dormancy. Therefore, the seeds expressed deep simple morphophysiological dormancy (MPD).

(The results of this research were introduced at KSHS 2017 Annual Autumn Conference through poster presentation)