• The Korean Journal of Ecology
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• v.19 no.3
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• pp.231-240
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• 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
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• 2003.10a
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• pp.38-42
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• 2003

This experiment was carried out the investigation of proper temperature of germination and growth responses of turf grass to different seedling ages. The results were as follows; 1. It was indicated that the proper temperature of germination was 30$^{\circ}C$ of day and 15$^{\circ}C$ of night, and day length was 14/10 hrs. 2. It was observed that 50 days of seedling was excellent with growth components such as number of tiller, length of tillering, number of node and internode length.

• The Korean Journal of Ecology
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• v.17 no.4
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• pp.485-499
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• 1994

This study was focused on the effect of the altitude on the geographical variations of germination characteristics in the populations of Plantago asiatica L. distribute in Mt. Chiri. There was a significant difference among the 14 groups in the phenological pattern in relation to altitudes. When the altitude becomes higher, the thermal time which was required for 10 to 80% germination rate showed higher and wider distribution. On the other hand, the germination response of increasing temperature (IT) and secreasing temperature (DT) regime was classified into 3 group. The first group was the spering germination type. This group showed that the IT regime hadhigher germination rate than that of the DT regime, and was distributed in Macheon(300m) and Packmudong (500m). The second was the spring-fall germination type which was distributed in Hadong (900m) and Saemt대 (1100m). This group also showed higher germination rate in the IT regime, but the difference of the germination rate between IT and DT regime was less than that in the first group (the spring type). The third group was the early fall germination type which was found in the Nogodan (1507m), Changetomok (1750m) and Cheonwangbong (1915m). The germination rate of this group showed almost 100% similarity between IT and DT regime. These data suggested that the geographical varations of germination characteristics within species was an important ecological strategy for the survival from severe environmental conditions.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.367-378
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• 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
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• v.45 no.1
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• pp.55-58
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• 2000

Germination of sweet and super sweet corn is lower than normal corn due to the higher sugar and lower starch contents of kernels. Sweet corn seeds are easily deteriorated in the field under the unfavorable condition, therefore it is important to identify the optimal harvesting time for seed production. This trial was conducted to investigate the responses of germination percentage of shrunken-2(sh2), brittle(bt), sugary(su), and sugary enhancer(se) hybrids in relation to harvesting dates. Eight hybrids of four different gene sweet corns were harvested at 15, 20, 25, 30, 35, 40, 45, and 50 days after silking(DAS). Germination test was performed using paper towel method. Mean germination percentages across eight hybrids showed the highest value at 45 DAS. There were significant differences among genes and within gene for germination. Shrunken-2 hybrid Mecca was higher than su hybrids for germination, indicating that sh2 would not be poorer than su Late harvesting beyond the optimal harvesting date might not be desirable because of more lodging and ear rots. Theoretical optimal harvesting date estimated from the regression equation was 40.9 DAS, however, practical date for harvesting would be a few days later than the estimated date if seedling vigor might be considered. Kernel dry weight per ear showed similar response to germination. Regression equation showed the highest kernel dry weight at 40.7 DAS. Significant correlations between kernel dry weight and germination were observed, impling that kernel dry matter accumulation would be an important factor for germination.

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

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.321-328
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• 2003

Various presowing seed treatments have been used to enhance the rates of germination and afterward seedling emergence. Seeds treated by them occasionally have not shown the same rate in indoor and field. The presowing treatments considering germination mechanism and factors affecting germination should be totally included in indoor experiments so that the results drawn could be reproduced in the field. Seed drying after the treatments and field conditions after sowing especially able to show Phytochromemediated responses related to light treatment must be determined prior to force the treatments to seeds. After set up these prerequisites to promote the rates of germination and emergence, many seed treatments proposed so far must be fixed how to be done; alone, sequential and simultaneous.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.184.1-184.1
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• 2013

It is generally known that electron beam has sterilization effects and can activate plant germination and growth. Compared to electron beam, electrical pulse has not been frequently studied with respect to the biological application. In this study, we have analyzed the effects of high voltage pulse on seed germination and growth using various plant species. We have used the high voltage generator for examining seed's responses to the high voltage pulse. The operating voltage and currents of the generator are about 300 kV and 30 kA, respectively. Pulse width is 60 ns. High voltage pulse has slightly activated germination and growth of radish during early stage. Various levels of germination and growth are observed in different plant species after treated with high voltage pulse.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.187-193
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• 1996

To supply seeds with a good quality as plant materials for herbicide screening and to know whether the germination characteristics could be associated with a differential response to herbicides, germination characteristics and differential responses to herbicides were investigated with 3 species of a genus Setaria ; Yellow foxtail(Setaria glauca P. Beauv, SETGL), Giant foxtail(Setaria faberi Hetrm, SETFA), and Green foxtail(Setaria viridis P. Beauv, SETVI). Degree of dormancy was high in the order of SETGL, SETVI and SETFA. The dormancy of SETGL seed was relatively well removed by room temperature and drying storage, but SETFA and SETVI by low temperature and wetting storage(stratification). For breaking dormancy of SETGL, SETVI and SETFA, it was necessary for being kept under the above storage conditions for at least 2, 4 and 4-5 months, respectively. When the dormancy-breaked seeds were transfered to low temperature($4^{\circ}C$) and drying condition, SETGL showed germination rate of 96% even after 2 month storage. However, SETVI and SETFA showed a decreased germination of 54% and 69%, respectively, with a decreased velocity of germination, indicating that secondary dormancy might be induced. On the other hand, a significant change in germination rate was not observed as the seeds were transfered to room temperature($25^{\circ}C$) and drying condition. The germinability of SETGL seed began to decline from 6th year after storage in room temperature and drying condition. All of 3 species showed relatively high germination rate at alternating temperature of $30^{\circ}C$/$20^{\circ}C$(14hr/10hr) and their germination were not increased by light. All of 3 species exhibited similar responses to cycloxydim, sethoxydim and primisulfuron in greenhouse experiment. In contrast, SETVI and SETFA were relatively susceptible to fenoxapropethyl, SETFA to fluazifop-butyl, SETGL and SETFA to clorimuron-ethyl, and SETGL to EK-2612. The difference in herbicidal response among 3 species was the highest in the treatment of EK-2612. These results suggest that there is no a consistent tendency in responses of 3 species to herbicides which have the same target site. And the relationship between germination characteristics and differential responses to herbicides was not found.

• The Korean Journal of Ecology
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• v.18 no.3
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• pp.353-366
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• 1995

To study the relationship between the germination response and geographical distribution, the seeds of Rumex acetocella were collected from nine sites (Taegwallyong, Alps lodge, Kans'ong, Sokch'o, Chumunjin, Suwon, Taechon, Sukgok, Mokpo) of different latitudes and altitudes. The populations of Rumex acetocella were subdivided into four groups based on the characteristics of the seed germination. The first group of Rumex acetocella (Taegwallyong, Alps lodge) germinated rapidly in early spring, the second group (Suwon, Teachon) in late summer through early autumn, and the third group(Sukgok, Mokpo) slowly in late autuman with various conditions. The thermal time values needed for the germination rate of 10% to 60% for these three groups indicated that the germination rate was low at the lower latitude, while it was increased as the latitude elevated. The population of the fouth group (Kansong, Sokcho, Chumunjin) showed the narrow optimum temperature range of germination response and the highest thermal time value to germinate 10% to 30% of seeds. The seeds in the high latitude region with relatively mild winter germinated synchronously in early autumn. These different germination responses of Rumex acetocella to geographic variations were thought to be an ecological strategy to survive in different environmental conditions.