• Korean Journal of Plant Resources
• /
• v.29 no.3
• /
• pp.339-346
• /
• 2016

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.

• Horticultural Science & Technology
• /
• v.32 no.4
• /
• pp.550-557
• /
• 2014

Heloniopsis koreana and Heloniopsis tubiflora (Melanthiaceae) are endemic herbaceous species of the Korean Peninsula. The Melanthiaceae family has been described as having seeds with small, underdeveloped embryos at the time of dispersal, and morphological (MD) or morphophysiological dormancy (MPD). However, there are few reports on embryo growth, morphology, and seed germination in Heloniopsis species. The aims of this study were to investigate embryo growth and seed dormancy, and to determine the type of dormancy exhibited by these species. The effects of incubation temperatures, light conditions, and gibberellic acid ($GA_3$) on dormancy break and seed germination were tested. Freshly matured seeds of the two species had small embryos that occupied about 9-11% of the length of the endosperm, and which increased by more than 300% in length before radicle emergence, indicating that the embryos are underdeveloped at the time of dispersal. Embryos in the seeds grew under warm temperature regimes (between $25/15^{\circ}C$ and $30/20^{\circ}C$). $GA_3$ application (tested only in the light) overcame seed dormancy and promoted germination. Approximately 30% of the seeds of H. koreana and approximately 40% of the seeds of H. tubiflora germinated in suitable environmental conditions (light and temperature) within 4 weeks. Therefore, 30-40% of the seeds of the two species exhibited MD, and the rest of the seeds had non-deep simple MPD. Light was found to be one of the critical factors for germination because no seed of either of the two Heloniopsis species germinated under constant dark conditions, and thus, these species have the potential to form a persistent soil seed bank. Understanding these germination requirements will help in development of effective strategies to increase the establishment of seedlings in their native habitat.

• Journal of Ecology and Environment
• /
• v.43 no.2
• /
• pp.254-262
• /
• 2019

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.

• Korean Journal of Agricultural Science
• /
• v.16 no.1
• /
• pp.56-61
• /
• 1989

In the present paper, we intented to analyze and to compare the different seed dormancy of two legume plants, Albizzia and Cercis. We found two different types of seed dormancy: one type of dormancy in Albizzia seed was caused by the water impermeability, and other type of seed dormancy was found in Cercis and it was induced by inhibitors. We confirmed that the extract substances from Cercis seed seemed to have strong regulational functions on the inhibition of seed germination and primary root growth of lettuce seed.

• Korean Journal of Plant Resources
• /
• v.35 no.6
• /
• pp.796-804
• /
• 2022

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℃) and intermediate temperature stratification (A, autumn temperature, 15/10℃) of alternating temperature stratification (S12-A4 or S12-A8 weeks). After dormancy break, 500 mg/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.

• Journal of Ecology and Environment
• /
• v.45 no.4
• /
• pp.174-181
• /
• 2021

Background: Euphorbia jolkinii Boiss. is a perennial species native to Jeju Island and the southern coastal area of Korea. Particularly on Jeju Island, the yellow flowers of E. jolkinii Boiss. have a high ornamental value because of their contrast with basalt. This study was conducted to investigate the effects of different temperatures (5, 15, 20, and 25 ℃) and gibberellic acid (GA₃) concentrations (0, 10, 100, or 1000 mg/L) on seed dormancy and germination of E. jolkinii. In addition, we classified the seed dormancy type and compared types with those of other species in the same genus. Results: The number of seeds with viable embryos and endosperms was approximately 66%. The final germination percentages at 5, 15, 20, and 25 ℃ were 51.7%, 83.5%, 2.6%, and 0.0%, respectively. In GA₃ concentration experiments, the final germination percentages of 0, 10, 100, and 1000 mg/L were 83.5%, 91.7%, 79.1%, and 83.4%, respectively, at 15 ℃ conditions, and 0.0%, 6.9%, 13.2%, and 27.3%, respectively, at 25 ℃. Conclusions: Germination improved at temperatures of 15 ℃ or lower. Furthermore, GA₃ treatment effectively reduced germination times. Thus, the seeds of E. jolkinni were classified as having non-deep physiological dormancy.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.39 no.3
• /
• pp.270-277
• /
• 1994

This study was conducted to investigate change of seed dormancy during storage in rice. The result of germination rate observed at different storage duration after harvest indicated that two Japonica rice varieties, Sangpungbyeo and Hwaseongbyeo, tow sare type local varieties, Jakwangdo and Mongeunsare, and a Tongil type rice, Samgangbyeo, showed no dormancy in rice seed harvested at 40 days after heading, However, weak dormancy was found in matured rice seed of Sobaekbyeo and Odaebyeo, and strong seed dormancy was found in Jungwonbyeo, IR-20 and IR-42. Rice seed stored for 30 days after harvest at 2$0^{\circ}C$ constant temperature or 25/15$^{\circ}C$ of day /night temperature fluctuation showed higher germination rate above 90% in all varieties tested. But germination rate of seeds stored at 4$^{\circ}C$ for 30 to 180 days showed varietal difference, higher in rice varieties having weak seed dormancy and lower in strong dormancy varieties. Days to 80% germination and average days for germination were shortened by storage for 30 to 180 days after harvest at 2$0^{\circ}C$, 4$^{\circ}C$ with RH 40% or day /night 25/15$^{\circ}C$ temperature condition in all rice varieties tested, but the degree of acceleration was lower at the condition of 4$^{\circ}C$ with RH 40%.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.90-90
• /
• 2017

Regulation of seed dormancy is important in many grains to prevent pre-harvest sprouting. To identify and understand the gene related to seed dormancy regulation, we have screened for viviparous phenotypes of rice mutant lines generated by insertion of Ds transposon in a Korean Japonica cultivar (Dongjin) background. One of the mutants, which represented viviparous phenotype, was selected for further seed dormancy regulation studies and designated dor1. The dor1 mutant has single Ds insertion in the second exon of OsDor1 gene encoding glycine-rich protein. The seeds of dor1 mutant showed a higher germination potential and reduced abscisic acid (ABA) sensitivity compared to wild type Dongjin. Over-expression of Dor1 complements the viviparous phenotype of dor1 mutant, indicating that Dor1 function in seed dormancy regulation. Subcellular localization assay of Dor1-GFP fusion protein revealed that the OsDor1 protein mainly localized to membrane and the localization of OsDOR1 was influenced by presence of a giberelin (GA) receptor OsGID1. Further bimolecular fluorescence complementation (BiFC) analysis indicated that OsDOR1 interact with OsGID1. The combined results suggested that OsDOR1 regulates seed dormancy by interacting with OsGID1 in GA response. Additionally, expression of OsDOR1 partially complemented the cold sensitivity of Escherichia coli BX04 mutant lacking four cold shock proteins, indicating that OsDOR1 possessed RNA chaperone activity.

• Asian Journal of Turfgrass Science
• /
• v.15 no.1
• /
• pp.15-20
• /
• 2001

Two types of annual bluegrass have been reported, and those consist of annual type (Poa annua ssp. annua) and perennial type (Poa annua ssp. reptans). As a weed, annual bluegrasses are commonly found in putting greens and fairways in many golf courses. Due to its strong competitiveness such as tremendous seed reproduction rate a year, prostrate growth habit, and no herbicide availability, annual bluegrasses have been considered as one of the most hard-to-control weeds in turf management systems. A growth chamber study was conducted to determine seed dormancy and to understand seed germination characteristics of annual bluegrass (Poa annua ssp. annua). Freshly harvested seeds showed 80 and 55% germination at 30 and $35^{\circ}C$, respectively, indicating that the optimum temperature of annual bluegrass is $30^{\circ}C$. However, the seed germination occurred only under light condition at any given temperature. This result demonstrated that light is prerequisite for the seed germination, and no primary dormancy of annual bluegrass seed exists. Secondary seed dormancy induced by unfavorable temperatures and dark condition was broken through 4 to 6 wk-storage at $4^{\circ}C$ with moisture, and the stored seeds germinated at $20^{\circ}C$ even under the dark. In red and far-red light trial, fresh seeds resulted in 40% germination under red while no seed germination occurred under far-red light condition, indicating that phytochrome Pr and Pfr could be related to annual bluegrass seed germination. When the far-red light replaced the red the germination was recovered, but this reversibility did not reach to the germination level under the red light only. This result implied that other lights than red and far-red would play an important role on seed germination of annual bluegrass.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.66 no.4
• /
• pp.375-382
• /
• 2021

For stable cultivation in double cropping, it is important to use potato (Solanum tuberosum L.) cultivars with a short dormancy period of 50-70 days and plant seed tubers of appropriate type and size. An experiment was conducted during 2018-2019 to investigate the effects of seed tuber type and size on growth and yield performance in double cropping. Whole tubers of three sizes (10-20 g, 30-40 g, and 50-60 g) and conventional cut tubers weighing 30-40 g from three cultivars with different dormancy periods, namely 'Daeji' (40-60 days), 'Eunsun' (50-60 days), and 'Saebong' (50-80 days), were planted, and their field performance was compared. Regardless of the cultivar, the increase in the whole tuber weight up to 30-40 g led to fast emergence, thereby increasing ground cover rate, shoot growth rate, and tuber growth rate, which ultimately improved tuber yield by 33-54%. Comparing the whole and cut tubers, 'Daeji' and 'Eunsun' showed similar growth and yield performance; as such, the performance of whole tubers weighing 10-20 g was comparable to that of cut tubers weighing 30-40 g. However, 'Saebong', a cultivar with relatively long dormancy period, performed better with cut tuber than with whole tubers. Based on these results, we recommend the use of whole tubers weighing over 30 g for double cropping. Further studies to break tuber dormancy are warranted in cultivars with relatively long dormancy periods (50-80 days), such as 'Saebong'.