Li, Song, Guan and Li (2020). Seed Science and Technology, 48, 2, 303-314. https://doi.org/10.15258/sst.2020.48.2.17 Seed dormancy and germination in Cardiocrinum giganteum var. yunnanense, a perennial herb in China with post-dispersal embryo growth Ye-Fang Li1, Jie Song2, Wen-Ling Guan1* and Feng-Rong Li1 1 Faculty of Horticulture and Landscape, Yunnan Agricultural University, Kunming 650201, PR China 2 Flowers Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650204, PR China *Author for correspondent (E-mail:
[email protected]) (Submitted February 2020; Accepted May 2020; Published online June 2020) Abstract Seeds of Cardiocrinum giganteum var. yunnanense, which is native to China, has underdeveloped embryos when dispersed from parent plants that did not grow until the second autumn and winter after exposure to summer temperatures. Radicles and cotyledons emerged in late winter and spring. Thus, a 15–16 month period was required from dispersal to seed germination. Under laboratory conditions, this period could be shortened to 5–6 months in a 25°C / 15°C (60 days) → 15°C / 5°C (60 days) → 5°C (60 days) temperature sequence. Based on dormancy-breaking requirements, the seeds have deep simple morphophysiological dormancy (MPD). This is practical knowledge for propagation of the species from seeds. Keywords: Cardiocrinum giganteum var. yunnanense, embryo development, morphophysiological dormancy, seed germination, temperature requirement Introduction Dormancy is a mechanism whereby seeds do not germinate during periods that may be favourable for germination but unfavourable for subsequent seedling establishment (Vleeshouwers et al., 1995). Differing climatic conditions are often reflected in the dormancy breaking requirements of seeds (Skordilis and Thanos, 1995).