Ecophysiology of seed dormancy and germination in four Lonicera (Caprifoliaceae) species native to Korea

Park, HyungBin,Ko, ChungHo,Lee, SeungYoun,Kim, SangYong,Yang, JongCheol,Lee, KiCheol The Ecological Society of Korea 2019 Journal of Ecology and Environment Vol.43 No.2

Background: To exploit the ornamental and medicinal purposes of Lonicera harae Makino, L. subsessilis Rehder, L. praeflorens Batalin, and L. insularis Nakai, native to Korea, it is necessary to understand their seed ecology for propagation. In this study, we investigated the seed dormancy type and germination characteristics of seeds of the four Korean native Lonicera species. Results: The seeds of the four Lonicera species imbibed water readily, suggesting that the species do not have physical dormancy. Furthermore, the seeds exhibited underdeveloped embryos with only about 15-25% of the length of the seeds at dispersal. The embryos grew to the critical length with approximately 50-80% of the length of the seeds' development before radicle protrusion. Further, 94.4% and 61.1% of freshly matured seeds of L. insularis and L. harae germinated within 4 weeks after sowing at 15 ℃ and 20 ℃, respectively. Contrarily, L. praeflorens and L. subsessilis seeds did not germinate within 4 weeks under all temperature treatments. At 15 ℃, L. praeflorens seeds started to germinate from 5 weeks and the final germination rate was 51.1% at 13 weeks. At 15 ℃, L. subsessilis seeds started to germinate from 5 weeks after sowing and the final germination rate was 85.6% at 17 weeks after sowing. Embryo growth and germination of L. praeflorens and L. subsessilis occurred at a relatively high temperature (≥ 15 ℃). Conclusions: Overall, L. insularis seeds have only morphological dormancy. The seeds of L. harae have approximately 60% and 40% of morphological dormancy and morphophysiological dormancy, respectively. Contrarily, L. praeflorens and L. subsessilis exhibited non-deep simple-type morphophysiological dormancy that requires relatively high temperature (≥ 15 ℃) for embryo growth and dormancy breaking. The optimum temperature for the germination of seeds of L. insularis, L. harae, L. praeflorens, and L. subsessilis was 15 ℃, 20 ℃, 15 ℃, and 20 ℃, respectively. There was interspecific variation in seed dormancy and germination patterns in the four Lonicera species. The difference in these characteristics within the four Lonicera species could be useful for understanding the seed ecophysiological mechanisms of Lonicera species.

Dormancy breaking and germination requirements of seeds of <i>Thalictrum uchiyamae</i> (Ranunculaceae) with underdeveloped embryos

Lee, Seung Youn,Rhie, Yong Ha,Kim, Ki Sun Elsevier 2018 Scientia horticulturae Vol.231 No.-

<P>Thalictrum uchiyamae Nakai is an herbaceous perennial plant that has potential for greater utilization for landscaping and medicinal purposes. In the present study, we investigated some of the factors that affect seed dormancy and germination in this species. To determine the temperature requirements for embryo growth and germination in field conditions, the seeds were buried in field soil. Every 1 or 2 weeks, the seeds were exhumed, and embryo growth, germination, and seedling emergence were investigated. In the laboratory, the effects of temperature and GA(3) on dormancy break and germination were investigated in order to characterize the seed dormancy. The seeds had underdeveloped embryos that were physiologically dormant at maturity in late September. In natural conditions, embryo growth and germination occurred in March of the following year, and seedlings emerged in early April. The physiological dormancy of the embryos was broken by cold stratification at 5 degrees C for 8 weeks, but warm temperatures (25/15 degrees C) were required to promote embryo elongation even after the physiological dormancy was broken. GA3 treatment could substitute for the cold stratification requirements and broke seed dormancy of T. uchiyamae, 87.3% of which germinated after 8 weeks of incubation at 25/15 degrees C at 100 mg.L-1 GA(3) soaking treatment. These results suggest that the seeds of T. uchiyamae exist in a state of non deep simple morphophysiological dormancy. The temperature requirements for the dormancy break of the seeds enabled the seedlings to emerge in the very beginning of the growing season the following year. These results represent practical knowledge for propagation of these plants from seed.</P>

한반도 자생식물 헐떡이풀 종자의 휴면유형과 발아특성

최한,이승연,이용하,이정호,김상용,이기철 한국자원식물학회 2018 한국자원식물학회지 Vol.31 No.4

Tiarella polyphylla D. Don is a native plant distributed only in Ulleung Island in Korea and has been traditionally used for medicinal purposes, although it is also used ornamentally. This study was conducted to determine the requirements for dormancy break and germination and to classify the type of seed dormancy. The experiments were performed with cold stratification (0 or 12 weeks at 5℃), warm stratification (0, 4, 8, or 12 weeks at 23℃, followed by 8 weeks at 5℃, and then incubation at 23℃), and GA3 treatments (0, 10, 100, or 1000 ㎎/L). The treated seeds were incubated on aseptic media at room chamber (23℃, a 16h photoperiod of fluorescent lamps with 40 μmol ․ m-2 ․ s-1). The seeds were dispersed in nature as underdeveloped embryos with no physical barrier to absorb water to prevent water absorption. However, the seeds did not germinate for 30 days after sowing without any pre-treatments. Thus, the seeds had morphological dormancy (MD) and physiological dormancy (PD). The final germination percentage following cold stratification (0 or 12 weeks) was 66.7% and 45.6%, respectively. The cold stratification delayed seed germination by about 3 weeks. In the warm stratification experiment (0, 4, 8, or 12 weeks), the final germination percentage was 21.1%, 27.8%, 41.1%, and 57.8%, respectively, 20 weeks after sowing. The embryos of the T. polyphylla seed grew in relatively warm temperatures (23℃). GA3 application overcame seed dormancy and promoted germination. Following GA3 treatment (0, 10, 100, or 1000 ㎎/L), the final germination percentage was 33.3%, 45.0%, 42.5%, and 72.5%, respectively. These results suggest that the T. polyphylla seeds had non-deep simple morphophysiological dormancy (MPD) and GA3 treatment could be used as a substitute for warm stratification for breaking seed dormancy. To our knowledge, this is the first report of seed dormancy characteristics of the genus Tiarella native to Korea. Key words - Gibberellic acid, Morphophysiological dormancy, Non-deep simple MPD, Saxifragaceae, Warm stratification 헐떡이풀은 우리나라에서 울릉도에서만 분포하는 자생식물로 전통적으로 약용으로 쓰여왔으며, 관상식물로의 활용도 기대되는 자원식물이다. 본 연구는 헐떡이풀 종자의 휴면타파와발아를 위한 조건을 확립하고 종자휴면 유형을 분류하고자 수행되었다. 실험은 헐떡이풀 종자에 저온층적처리(5℃에서 0, 12주)와 고온층적처리(23℃에서 0, 4, 8, 12주 처리 후에 5℃에서 8주, 다시 23℃에서 배양함), GA3 (0, 10, 100, 1000 ㎎/L)처리를 수행하였다. 이렇게 처리한 종자는 무균배지에 소독하여파종하고 온도 23℃, 광도 40 μ㏖․m-2 ․ s-1 PPFD, 일장 16시간조건의 배양실에서 배양하였다. 헐떡이풀 종자는 자연상태에서 미숙배인 상태로 탈리되며, 종자 내부로의 수분흡수에 대한물리적인 장벽은 없었다. 그러나 아무 처리 없이 파종하였을 때30일이 지나도록 전혀 발아하지 않았다. 따라서 헐떡이풀 종자는 형태적 휴면(MD)과 생리적 휴면(PD)을 가지고 있는 것으로판단하였다. 저온층적처리(0, 12주) 실험의 최종 발아율은 각각66.7%, 45.6%로 나타났다. 저온처리는 오히려 발아를 약 3주 정도 지연시켰다. 고온층적처리(0, 4, 8, 12주) 실험에서는 최종발아율이 각각 13.3%, 24.4%, 20.0%, 51.1%로 나타났다. 헐떡이풀 종자의 배는 상대적 고온에서 발달하였다. GA3 처리는 종

Role of Temperature and Gibberellic Acid in Stimulating Embryo Elongation and Radicle Emergence of Hepatica asiatica Nakai Seeds

Young Shin Chon,Kyeong Jin Jeong,Sang Woo Lee,Jae Gill Yun 한국원예학회 2015 원예과학기술지 Vol.33 No.3

This research was performed to determine the temperature requirements for embryo growth and radicle emergence of Hepatica asiatica Nakai, a perennial herb native to Korea. Seed viability, embryo growth, and radicle emergence were monitored in seeds exposed to various temperatures (10, 15, 20℃ and 30→15℃). Laboratory experiments at various temperatures revealed that (1) embryo elongation occurred effectively between 10 and 15℃; (2) radicle emergence occurred only at 15℃; (3) a warm stratification (2-8 weeks at 30℃) was not required for embryo elongation and radicle emergence, and led to inhibition of radicle emergence; (4) application of gibberellic acid (GA3) promoted embryo growth, but not radicle emergence. These results suggested that H. asiatica seeds have two separate mechanisms to overcome dormancy, either by GA3 (morphological dormancy) or temperature (physiological dormancy), and warm stratification is not involved in breaking radicle dormancy. These findings indicate that H. asiatica seeds have morphophysiological dormancy.

Dormancy-breaking and Germination of Chelidonium majus L. subsp. asiaticum H. Hara Seeds by Stratification and Gibberellins

Boran Ji(Boran Ji),Hayan Lee(Hayan Lee),Kyungtae Park(Kyungtae Park),Sang Yeob Lee(Sang Yeob Lee),Bo-Kook Jang(Bo-Kook Jang),In Hwan Chae(In Hwan Chae),Chung Youl Park(Chung Youl Park),Sung Pil Kwon(S 한국자원식물학회 2022 한국자원식물학회지 Vol.35 No.6

The demand for Chelidonium majus L. subsp. asiaticum H. Hara is expected to increase due to its pharmacological properties such as antibacterial, antioxidant, and anti-inflammatory effects. However, an effective propagation system for this species has not yet been established. This study was conducted to analyze the seed dormancy and germination characteristics of C. majus L. subsp. asiaticum H. Hara native to Korea and establish a mass propagation system. The dormancy type was primarily classified by analyzing the general information of the collected seeds. The seed dormancy breaking was investigated by comparing the effects of cold stratification (0, 2, 4, 8, 10, or 12 weeks) with warm stratification (S, summer temperature, 25/15°C) and intermediate temperature stratification (A, autumn temperature, 15/10°C) of alternating temperature stratification (S12-A4 or S12-A8 weeks). After dormancy break, 500 ㎎/L GA3 and GA4+7 treatment replaced cold stratification and improved seed germination. The results of this study are expected to provide basic data for future seed propagation and mass propagation by analyzing the dormancy and germination characteristics of C. majus L. subsp. asiaticum H. Hara seeds.

Role of Temperature and Gibberellic Acid in Stimulating Embryo Elongation and Radicle Emergence of Hepatica asiatica Nakai Seeds

Chon, Young Shin,Jeong, Kyeong Jin,Lee, Sang Woo,Yun, Jae Gill Korean Society of Horticultural Science 2015 원예과학기술지 Vol.33 No.3

This research was performed to determine the temperature requirements for embryo growth and radicle emergence of Hepatica asiatica Nakai, a perennial herb native to Korea. Seed viability, embryo growth, and radicle emergence were monitored in seeds exposed to various temperatures (10, 15, $20^{\circ}C$ and $30{\rightarrow}15^{\circ}C$). Laboratory experiments at various temperatures revealed that (1) embryo elongation occurred effectively between 10 and $15^{\circ}C$; (2) radicle emergence occurred only at $15^{\circ}C$; (3) a warm stratification (2-8 weeks at $30^{\circ}C$) was not required for embryo elongation and radicle emergence, and led to inhibition of radicle emergence; (4) application of gibberellic acid ($GA_3$) promoted embryo growth, but not radicle emergence. These results suggested that H. asiatica seeds have two separate mechanisms to overcome dormancy, either by $GA_3$ (morphological dormancy) or temperature (physiological dormancy), and warm stratification is not involved in breaking radicle dormancy. These findings indicate that H. asiatica seeds have morphophysiological dormancy.

Role of Temperature and Gibberellic Acid in Stimulating Embryo Elongation and Radicle Emergence of Hepatica asiatica Nakai Seeds

윤재길,천영신,정경진,이상우 한국원예학회 2015 원예과학기술지 Vol.33 No.3

This research was performed to determine the temperature requirements for embryo growth and radicle emergence of Hepatica asiatica Nakai, a perennial herb native to Korea. Seed viability, embryo growth, and radicle emergence were monitored in seeds exposed to various temperatures (10, 15, 20°C and 30→15°C). Laboratory experiments at various temperatures revealed that (1) embryo elongation occurred effectively between 10 and 15°C; (2) radicle emergence occurred only at 15°C; (3) a warm stratification (2-8 weeks at 30°C) was not required for embryo elongation and radicle emergence, and led to inhibition of radicle emergence; (4) application of gibberellic acid (GA3) promoted embryo growth, but not radicle emergence. These results suggested that H. asiatica seeds have two separate mechanisms to overcome dormancy, either by GA3 (morphological dormancy) or temperature (physiological dormancy), and warm stratification is not involved in breaking radicle dormancy. These findings indicate that H. asiatica seeds have morphophysiological dormancy.

Seed Dormancy and Germination in Iris laevigata (Iridaceae), A Rare Species in Korea

Chung Ho Ko,Seung Youn Lee,Sang Im Oh,Eun Hye Park,Min Gil,Soo Hoon Kim,Mi Jeong Yoon 한국화훼학회 2022 화훼연구 Vol.30 No.2

Iris laevigata, which belongs to the Iridaceae, is now designated as an “endangered” (EN) grade by Korea Forest Service because it does not have many natural sites known for its reckless development and damage to its natural habitats. This study was carried out to establish the propagation protocol from seed to restore the native habitat of the I. laevigata and to utilize it for ornamental purposes. Basically, the appearance and internal structure of seeds were observed and imbibition experiments were conducted. Germination rate was measured by cold stratification experiment, after warm followed by cold stratification experiment, and GA3 treatment experiment. The seeds had underdeveloped embryos, which had grown to about 25% of those of fully matured seed before germination. In the controlled laboratory experiment, after cold stratification at 5°C for 0, 4, 8, or 12 weeks, the seeds germinated to 0, 11.7, 43.4, or 51.7%, respectively, after 4 weeks of incubation at 25°C. After warm stratification (25°C, 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 4 weeks of incubation at 25°C. GA3 treatment did not overcome the dormancy. Our study determined the dormancy type of I. laevigata seed. Imbibition experiments showed that there was no physical dormancy, and it was also found that there was an underdeveloped embryo when it was observed that the embryo was growing according to the period of incubation. A nd t he e m bryo grew a t relatively w arm temperatures. It is concluded that the seeds of I. laevigata have morphophysiological dormancy (deep simple MPD). This is the first report to determine the dormancy type in seeds of this valuable ornamental plant.

Seed Germination and Dormancy Breaking of Thalictrum rochebrunianum var. grandisepalum (H. Lev.) Nakai

Cho, Ju Sung,Kwon, Hyuk Joon,Lee, Cheol Hee The Plant Resources Society of Korea 2016 한국자원식물학회지 Vol.29 No.3

This study was carried out to develop an effective seed propagation method for Thalictrum rochebrunianum var. grandisepalum (H. Lev.) Nakai by analyzing seed dormancy types and germination characteristics. Seeds were collected between September to October at Gangwon province, and well-selected seeds were used while being dry-stored at 4±1℃. The seed size ranged 4.52 × 1.58 ㎜ and the weight of thousand seeds were 1,603.5 ± 0.02 ㎎. The moisture content was 7.2%. Seeds were achene type, and morphology characters showed an elliptical shape and rough texture, and light brown in color. Moist-chilling treatment was conducted for dormancy breaking because the seeds had an undeveloped embryo of liner type. The embryo had developed during a moist-chilling period, constantly, and fully developed in 10 weeks. Consequently, it seemed to be non-deep complex or intermediate complex type of morphophysiological dormancy, and embryo dormancy was broken by wet-chilling for 10 weeks. After 10 weeks of wet-chilling treatment, seed germination began. Germination percentage was higher in dark condition raher than light condition and recorded the maximum at 25℃ in the dark (16.3%). A pre-soaking treatment with a combined plant growth hormones promoted germination and shortened T₅₀. Specifically, seed germination of 84.5% was achieved by pre-soaking of seeds with a combined solution of 500 ㎎/L GA₃ and 10 ㎎/L kinetin for 24 h after a wet-chilling treatment for 10 weeks. Thus the effect of plant growth hormones coupled with chilling temperature on seed breaking dormancy provide asubsequent growth of seedlings for successful plantation.

Seed dormancy and germination in Oenanthe stolonifera as affected by temperature and gibberellic acid

김현진,나해영 한국원예학회 2021 Horticulture, Environment, and Biotechnology Vol.62 No.1

Our aim was to investigate the dormancy type of water dropwort seeds for developing seed germination methods in thefuture. The mature fruit is a schizocarp with sponge-like and thickened ribs. However, the seeds were able to absorb moisturenormally. In this study, less than 14% of seeds germinated without any pretreatment after 4 weeks at 20, 25, or 25/15 °C(12/12 h). However, there was a further increase in germination percentage after 10 weeks of incubation at 5/5, 15/6, 20/10,and 25/15 °C. The seeds germinated at higher ratios under relatively colder temperature regimes. Embryo growth in theseeds occurred at both warm and cold temperatures. However, water dropwort seeds require a period of cold temperatures forembryo growth to be completed. The germination percentage was signifi cantly higher in GA 3 -treated seeds, even though theabsolute diff erence was relatively low. In water dropwort, GA can overcome seed dormancy but cold temperature alone for8–10 weeks may eff ectively break seed dormancy and increase germination percentage. Based on these results, we proposethat most water dropwort seeds showed intermediate complex morphophysiological dormancy and some seeds had morphologicaldormancy at the time of dispersal. These results provide useful information for seed propagation and a practicalproduction plan for cultivation of water dropwort.