Comparison of the seed dormancy and germination characteristics of six Clematis species from South Korea

Abstract

• Six Korean Clematis species display morphological or morphophysiological dormancy. • Germination indices are improved in Clematis seeds by 100 mg/L GA 4+7 treatment. • Dormancy is broken by temperature stratification in C. trichotoma and C. terniflora . Clematis species are perennial woody or herbaceous vines that are popular medicinal and ornamental horticultural plants. The seeds of six species were collected from five sites, and their germination characteristics and dormancy types were investigated. Seeds of all species had a typical achene morphology of a seed pod with a tail. Small, rudimentary embryos (0.14 to 0.29 E:S ratio) were observed, and the seeds showed sufficiently good water absorption (53.9–72.4%). Germination occurred within 30 days for C. apiifolia (light and dark conditions, 66.3% and 90.5%, respectively), C. heracleifolia var. urticifolia (77.0 and 92.5%), C. heracleifolia (37.3 and 88.3%), and C. serratifolia (1.0 and 96.5%). Germination was promoted using gibberellin treatments. Furthermore, the seeds of C. terniflora and C. trichotoma broke dormancy with short-term cold temperature stratification, and the embryos developed and germinated at warm temperatures. We concluded that the seeds of C. apiifolia, C. heracleifolia var. urticifolia, C. heracleifolia , and C. serratifolia are morphologically dormant whereas those of C. terniflora and C. trichotoma are morphophysiologically dormant. This study provides seed propagation and dormancy information for six Clematis species native to Korea.