Morphological and Morphophysiological Dormancy in Seeds of Two Genera (Heloniopsis and Thalictrum) Native to Korea

Abstract

This study was conducted to find basic information for the research of morphological dormancy in seeds of two genera (Heloniopsis and Thalictrum) native to Korea. Seeds of Heloniopsis koreana, Heloniopsis tubiflora, Thalictrum rochenbrunianum, Thalictrum uchiyamai, and Thalictrum coreanum were collected, and embryo morphology and seed germination were investigated. All seeds of five species had underdeveloped embryos which occupied about 10-20% of the full seed length at maturity. The seeds of H. koreana and H. tubiflora had rudimentary embryos. The seeds of T. rochenbrunianum, T. uchiyamai, and T. coreanum had intermediate type between rudimentary and linear embryo. The small embryos of all seeds of five species grew to a critical length before radicles emerge from the seeds. At 30 days after sowing, the seeds of H. koreana and H. tubiflora germinated to 22.7% and 40.7%, respectively. On the other hand, the seeds of T. rochenbrunianum, T. uchiyamai, and T. coreanum germinated to 12.5%, 3.3%, and 0%, respectively. If embryo growth and germination in seeds are completed in approximately 30 days, the seed are said to have morphological dormancy (MD). However, if the seeds require > 30 days for germination, they are considered to have morphophysiological dormancy (MPD). Thus, the seeds of H. koreana and H. tubiflora had about 78% and 60% MPD, respectively. On the other hand, the seeds of T. rochenbrunianum, T. uchiyamai, amd T. coreanum had about 87%, 96%, and 100% MPD, respectively. There was a different level of dormancy (MD and MPD) within the same seed population examined. Therefore, germination of the seeds was delayed due to the underdeveloped embryos. This result could contribute to determine morphological seed dormancy and germination mechanism in seeds of the Korean Peninsula.

Seed Germination Responses and Interspecific Variations to Different Incubation Temperatures in Eight Veronica Species Native to Korea

“…그러나 C. coreana의 종자는 10, 15, 20, 25°C 온도범위에서 한 달간 층적처 리를 받은 뒤 5°C 온도에서 두 달간의 층적처리 시 90% 이상의 발아율을 보였다고 하여, 종간 차이를 보고한 바 있다 (Roh et al, 2008). Heloniopsis속 식물 중 처녀치마(H. koreana)와 숙근처녀치마(H. tubiflora)의 종자는 각각 22%와 40%의 형태적휴면 (MD)과 78%와 60%의 형태생리적휴면(MPD)이 있다고 보고되었는데 (Lee et al, 2014), 일본 자생종인 H. orientalis의 종자 는 30일 이내에 대부분 발아하여 형태적휴면(MD)을 보인다고 보고된 바 있다 (Takahashi, 1984;Baskin and Baskin, 2014). 뿐 만 아니라, Hosta plantaginea는 형태생리적휴면(MPD)을, H. minor는 형태적휴면(MD)를 갖는다고 하여, 같은 속(genus) 내 에서도 종간에 전혀 다른 휴면유형을 보이는 분류군이 다수 보고되고 있다.…”