• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.21 no.3
• /
• pp.47-56
• /
• 2018

Research was initiated to investigate germination characteristics and germination pattern of 14 herbaceous plant entries used on the road slope during 30 days. An alternative germination condition for 14 herbaceous plant entries required by International Seed Testing Association(ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$. Significant differences were observed in the first germination rate(0.3%~40.7%)and in the final germination rate(7.7%~93.3%). Days to the first germination(2~8days), days to the 30% germination(2~6days) and days to the peak germination(6~18days) were different among 14 herbaceous plant entries in the study. From this result, we could find out higher final germination rate of 14 herbaceous plant entries in the following order; First, forage crops and cool-season turfgrasses; Second, herbeceous flowers; Third, wild plants. We could also divide germination rate among 14 herbaceous plant entries as 6 groups(I;very high, II;high, III;medium high, IV;medium low, V;low, VI;very low) based on the final germination rate and divide germination speed as 5 groups(A;very fast, B;fast, C;normal, D;slow, E;very slow)based on days to the peak germination. Considering germination characteristics and pattern of 14 herbaceous plant entries Medicago sativa, Lolium perenne, Festuca arundinacea and Cosmos sulphureus were regard as dominating species while Lespedeza cuneata, Silene armeria, Lotus corniculatus var.japonicus, Coreopsis tinctoria and Centaurea cyanus as competitive species following dominating species. However, Chrysanthemum burbankii, Pennisetum alopecuroides, Chrysanthemum boreale., Artemisia princeps var. orientalis and Arundinella hirta were not almost expected to emerge.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10b
• /
• pp.43-43
• /
• 2003

Multiple regression equations (Rehman et al. 2000) have been developed to predict the salinity tolerance of Acacia seeds, expressed as the I$\sub$50/ (the concentration of NaCl required to reduce final germination to 50% of the control value in DW). Accurate predictions can be made using one or more chemical and biological seed parameters. In this study the theoretical effect of varying final germination percentage in distilled water, germination rate in distilled water. (Rate), Ca$\^$2+/ or K$\^$+/ contents and their ratios, as independent factors or related factors, on the predicted salinity tolerance (I$\sub$50/) of Acacia species was investigated. Simulation of the effects of changing final germination, rate, calcium and potassium suggest the possibility of practical application of these results to modify the salinity tolerance of seeds. The predicted I$\sub$50/ increased with increasing final germination. Similarly, the higher the rate of germination, the higher the predicted salt tolerance of Acacia species. The Ca$\^$2+/ content of seeds was found to be positively correlated with I$\sub$50/. Species with higher Ca$\^$2+/ contents had a higher I$\sub$50/. This suggests that I$\sub$50/ might be increased by increasing the Ca$\^$2+/ contents of seeds by pretreatment with calcium salts or by supplying these to the mother plants.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.2 no.4
• /
• pp.229-234
• /
• 2021

Iris dichotoma Pall. found on Daechung Island in Korea has been designated as an endangered species. To aid in conservation efforts of this species, this study investigated its germination characteristics and seed dormancy type. Four sets of seeds were incubated at different temperatures (4/1℃, 15/6℃, 20/10℃, and 25/15℃). One set of seeds was cold stratified (4 weeks at 4/1℃). The final germination rate and mean germination time showed that the optimal germination temperature was 25/15℃. Final germination rates were ~70%, showing no significant difference among temperature treatments. However, mean germination time were significantly different among all temperature treatments except for 4/1℃. Mean germination time for seeds with temperature treatments of 15/6℃, 20/10℃, and 25/15℃ were 3.2, 2.1, and 1.5 weeks, respectively. At 25/15℃, the mean germination time was half of that at 15/6℃. Seeds of I. dichotoma had fully developed embryos at the time of dispersal. No additional growth of the embryo was observed. Cold stratification did not affect the final germination rate or the mean germination time. This study shows that seeds of I. dichotoma have no physiological or morphological dormancy, unlike other members of the Iris genus known to have seed dormancy that needs a relatively high incubation temperature (≥25/15℃) for mass propagation to occur. These results will be useful for understanding ecophysiological mechanisms related to the species' habitat. They are also useful for mass propagation of I. dichotoma for the purpose of conserving this endangered species.

• The Korean Journal of Ecology
• /
• v.19 no.3
• /
• pp.231-240
• /
• 1996

The germination responses of Cassia mimosoides var. nomame seeds to temperature were examined under various conditions. The temperature range allowing germination was $20~40^{\circ}C$, and the linear relationship between the germination rate and temperature appeared to exist between $28~38^{\circ}C$ The total thermal time required for germination (10~80%) of C. mimosoides seeds ranged from 259 Kh (degree Kelvin$\times$hours) to 421 Kh and base temperature range was relatively constant, i.e., $23.39~26.68^{\circ}C$. In the increasing temperature (IT) regime, C. mimosoides seeds started to germinate at $16^{\circ}C$ and showed greater germination rate with increasing temperatures. The final germination rate was 64% at $36^{\circ}C$. On the other hand, in the decreasing temperature (DT) regime, the seeds began to germinate at $36^{\circ}C$, and the final germination rate was 52% at $20^{\circ}C$. An induced dormancy occurred at $16^{\circ}C$ in the DT regime.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2023.04a
• /
• pp.23-23
• /
• 2023

The Hairy labrador tea (Ledum palustre L. var. diversipilosum Nakai) is a evergreen small shrub, belonging to the Ericaceae and mainly distributed along the alpine areas of Hamgyeong-do in North Korea. Through seed physiological research on North Korean plants, we intend to obtain basic data for the development of mass propagation methods and use them for vegetation restoration. The internal and external morphological characters of the seed were observed using scanning electron microscopy or stereoscopy, and full seeds were selected through X-ray test. Seeds were cultured on a growth condition at 15/6℃ and 25/15℃ to examine the germination response according to temperature, and the number of germinated individuals was examined every 24 hours to calculate germination percentage and mean germination time. Low-temperature treatment (4℃) and hormone treatment (GA3) were performed to investigate the effect of dormancy breaking, and analysis of variance (ANOVA) was performed on the experimental results using SAS 9.4. The seeds of the Hairy labrador tea were elliptical-narrow in shape, and the epidermal cell wall pattern was reticulated. The final germination rate (FGP) was the highest at 58.9% under the condition of low temperature treatment at 25/15℃. The average number of days to germination (MGT) was the highest at 25.1 days without treatment at 15/6℃, and the average of the last germination days was confirmed to be about 13 days. As a result of low temperature treatment, it was confirmed that the final germination rate (FGP) increased by 43.3%. The significance of the final germination rate (FGP) was verified according to the pretreatment at 25/15℃.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.1
• /
• pp.25-29
• /
• 2004

The responses of soybean seeds were evaluated to accelerated aging and gamma irradiation with regard to germination, seed leakage, seed leachate component and dry weight of hypocotyl and primary root of the germinating seed. Accelerated aging significantly reduced the final germination rate while gamma irradiation increased the final germination rate. Furthermore, the interactive effects occurred that the final germination rate of 5-day aged seeds increased considerably in response to 4 Gy of gamma irradiation. The extent to which the electrolyte was leaked from the seeds (conductivity) was significantly affected by accelerated aging and showed a close negative correlation with the germination rate. Gamma irradiation, however, did not significantly affect the electrical conductivity of seed leachate. The accelerated aging significantly increased the concentrations of the particular electrolytes leaked from the seeds while the gamma irradiation did not affect those concentrations. Of the electrolytes leaked from the seeds, Ca and Mg showed relatively lower concentrations while K showed greater concentrations than others. Moreover, N and P showed similar responses to aging treatment. Aging treatment significantly affected dry weight (DW) of hypocotyls and primary root. Also, gamma irradiation decreased DW of hypocotyls and primary root, particularly for 8 Gy associated with 5 days aging treatment. The data were discussed in terms of the relationships of seed vigor with aging treatment and gamma irradiation.

• 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 Plant Resources
• /
• v.32 no.5
• /
• pp.457-462
• /
• 2019

This study was conducted to investigate seed dormancy type and germination characteristics of Lonicera chrysantha. In imbibition test, the seeds imbibed water readily. Therefore, the seeds did not have physical dormancy (PY). The seeds have undeveloped embryo at seed dispersal and, then the E:S ratio (embryo/seed ratio) increased more than about 46% just before germination. In temperature experiments (5, 15, 20 and $25^{\circ}C$), the seeds did not germinate during incubation at $5^{\circ}C$. At $20^{\circ}C$, the seeds started to germinate from a week after sowing and the final germination was 86.7% at 2 weeks after sowing. At $15^{\circ}C$, the seeds started to germinate at 2 weeks and the final germination rate was 75.0% at 4 weeks after sowing. At $25^{\circ}C$, the seeds started to germinate at a week and the final germination rate was 48.3% at 19 weeks after sowing. Consequently, Optimum temperature of germination is $20^{\circ}C$ that shown highest final germination rate and shortest mean germination time. The seeds germinated all temperature treatments within 4 weeks except to $5^{\circ}C$. Therefore, it is concluded that seeds of L. chrysantha have only morphological dormancy (MD).

• The Korean Journal of Ecology
• /
• v.17 no.3
• /
• pp.367-378
• /
• 1994

The germination responses of Echinochloa crus-galli (L.) Beauv. seeds to temperature were examined under the various thermal conditions. While almost all the seeds tested did not germinate immediately after collection, almost of the seeds which were stored for 7, 10, and 17 months showed very high germination percentages (85-95%) at their own constant temperatures between $16^{\circ}C\;and\;40^{\circ}C$. The total thermal time which was required for germination(10-70%) of Echinochloa crus-galli seeds ranged from 539Kh(degree Kelvin X hour) to 1,279Kh in accordance with the distribution function of thermal time, $F({\Theta})=1-[3D^{-3}({\Theta}-m+D)+1]^{-1/2}$, where m is 935Kh and D is 555Kh. Moist chilling treatment at $2^{\circ}C$ for 20 days increased the final germination percentage as well as the germination rate. In the increasing temperature(IT1 regime, E. crus-galli seeds started to germinate at $12^{\circ}C$. and showed greater germination rate with increasing temperatures, with the final germination percentage of 80%. On the other hand, in the decreasing temperature(DT1 regime, the seeds began to germinate at $12^{\circ}C$(10% germination) with the final germination percentage of 20%. An induced dormancy occurred at $4^{\circ}C$ in the DT regime.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.43 no.1
• /
• pp.1-5
• /
• 1998

Experiments were carried out to find out the optimum water potential, temperature, and duration for the priming of rice seeds, Oryza sativa L. (cv. Ilpumbyeo) for better germination at sub-optimal temperatures. Seeds were primed in 0, -0.2, -0.4, -0.6, -0.8, and -1.0 MPa PEG (polyethylene glycol) solutions at $25^{\circ}C$. The optimum water potential for seed priming, the highest water potential at which rice seeds did not germinate, was -0.6 MPa. To find out optimum priming temperature and duration rice seeds were primed in -0.6 MPa PEG solution and 0 MPa (water as a control) for various durations at 15 and $25^{\circ}C$ and the seeds were germinated at 17, 20, and $25^{\circ}C$. Considering germination rate and speed, the optimum priming time in water (0 MPa) was 4 days at 15$^{\circ}C$ and 1 day at $25^{\circ}C$, while 4 days was the optimum priming time in a -0.6 MPa PEG solution, regardless of the priming temperature. Priming reduced the actual time of germination, especially at sub-optimal temperatures. Priming did not affect germination rate in -0.6 MPa PEG solution at 15$^{\circ}C$, but overpriming reduced the final germination rate in water at 15$^{\circ}C$ and in -0.6 PEG solution at $25^{\circ}C$. Total sugars and $\alpha$-amylase activity induced during the seed priming were negatively correlated with the final germination rate and there was no noted relationship with the speed or uniformity of germination.