GERMINATION REQUIREMENTS IN CAREX-KOBOMUGI (SEA ISLE)

Laboratory and field germination experiments in Carex kobomugi seeds were pursued to clarify their germination requirements and availability of the requirements in the field. In the laboratory experiments, more than 50 % of the seeds of C. kobomugi germinated under 35/30C or 25/20C when they were scarified with 98 % H2SO4 after removal of their utricles, and chilled in moist condition for 28 to 42 d. Seeds with utricles or those without scarified with H2SO4 did not germinate. Seeds sown at 10-cm depth at the Kado-ori coast on 11 February 1991 after soaked in H2SO4 showed 40 % germination by 29 April 1991, whereas those without H2SO4 treatment did not germinate. These results suggest that seed-coat impermeability and embryo immaturity are possible causes of the dormant state in seeds of C. kobomugi ripen in summer. In the field, the moist-chilling condition is available in winter and the seeds can germinate in the following spring if the seed-coat impermeability is relaxed before winter.