• ALGAE
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• v.25 no.1
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• pp.27-35
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• 2010

Marked declines in seagrass meadows are increasingly being reported from coasts around Korea and many regions of the world. The transplantation of seagrasses has been attempted to mitigate and control their degradation from a range of anthropogenic factors. In this study, Zostera marina shoots, which were collected from a donor bed in Koje Bay, were transplanted in Jindong Bay in December 2004. In 2008, a comparative investigation of shoot morphology, growth, and reproduction strategy of Z. marina was carried out between the donor and transplant sites to assess their adaptation success. Shoot height, individual shoot weight, and leaf productivity at the transplant site were significantly greater than those at the donor site. However, below-/aboveground tissue ratio was significantly lower at the transplant site compared to the donor site. Z. marina survival was maintained through vegetative reproduction, while peak season for lateral shoot recruitment was late winter for both donor and transplant site populations. However, vegetative reproduction mainly occurred during late winter and spring at the transplant site, whereas lateral shoots were evident across all seasons except late spring in the donor site. More pronounced seasonal variations were found at the transplant site compared to the donor site. These results indicate that Z. marina populations at the two sites possess distinct phenotypic variations induced by different environmental conditions, and Z. marina transplants have adapted well to the new transplant environment.

• Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.121-128
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• 2021

The variations of morphological features, density and biomass of vegetative shoots and characteristics of reproductive shoots of Zostera caespitosa were examined in Tongyeong, Korea. Morphological features such as leaf length, width and sheath length of Z. caespitosa showed significant seasonal variation (p < 0.001). The highest aboveground value was recorded in late spring to summer and the lowest value in winter. Density and biomass also showed seasonal variations. Annual average shoot density and biomass of Z. caespitosa were recorded as 1,223.4 leaf m^-2 and 5,956.9 g w.w.m^-2, respectively, and had the highest value in June and lowest values in November and January. Reproductive shoots were observed from April (13℃) to June (21℃). Pistils erected outside sheath, anther dehiscing and small embryos were found in April. Mature fruit and released seeds were found in May and June. These results suggest that this species had a high growth rate in late spring and early summer (15℃-20℃). Reproductive shoots of Z. caespitosa may initially appear at about 10℃ in spring and seed have been released at about 20℃ in fall.

• Plant Resources
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• v.7 no.3
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• pp.222-225
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• 2004

In Japan, propagation of cyclamen is mainly from seedlings. However, seeds are expensive and germination is slow and non..uniform. Therefore, to achieve genetically uniform propagation, multiplication must be vegetative. The rooted tuberous stems without shoots as sources of explants were cultured on the media containing BA and sucrose. After 30 days cultivation, tuberous roots were produced from the root ends attached to a tuberous stem and its capability was dependent on the type of media. The highest percentage of tuberous root formation was observed in Culture on the medium of 1/3 MS containing 0.05mgL$^{-1}$ NAA, 0.5mg L$^{-1}$ BA and 5% sucrose. Growth rates of the tuberous roots were greatly influenced by the cutting positions of a root in explants. The highest growth of was observed if small amount of root end was cut at initiation of tissue culture.

• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.339-346
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• 2002

From March 1998 to August 2000, the phonology and morphometrics change of Zostera caespitosa Miki were examined at the Duksan Port in the eastern coast of Korea. Morphometric characteristics (shoot height, leaf length, sheath length, leaf width, and number of leaf per shoot), size and number of reproductive structures (spathe, spadix, and seeds), shoot density, biomass and physiochemical parameters (water temperature and nutrient concentrations) were measured. Significant differences between months (p < 0.05) existed for morphometric characteristics except for sheath length. The sequence of shoot heights clearly showed cyclical annual variation with water temperature. Vegetative shoots of Z. caespitosa were present throughout the year, but reproductive shoots were rarely occurred from mid January to early April in water temperature of $9-12^\circ{C}$. Flowering in the spathe began in mid February, and seed maturing was occurred in early April. Water column nitrate and phosphate concentration showed seasonal variation, but ammonia concentration was variable with season. Relationships between shoot morphometrics and physiochemical parameters were not significantly correlated but water temperature seemed to regulate the re-productive phase and annual life cycle. The mean shoot density and above biomass of the populations were $511.6\pm{25.6}\;shoots\;m^{-2}$ and $413.4\pm{19.8}\;g\;dry\;wt\;m^{-2}$, respectively.

• Journal of Forest and Environmental Science
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• v.39 no.3
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• pp.150-154
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• 2023

Heloniopsis orientalis (Liliaceae) is an important horticultural crop native to Korea. Under natural conditions, germination is poor and plant growth is delayed. Therefore, we have developed a vegetative propagation method to produce plants with vigorous growth characteristics via tissue culture. The regenerated shoots were then initiated directly from leaf explants on an MS medium containing either 0.5 to 2.0 mg/L 2,4-D or 1.0 to 3.0 mg/L BA. Healthy plantlets with adventitious roots were formed on the medium supplemented with 1.0 mg/L BA (81%). BA triggered callus initiation without caulogenesis or rhizogenesis, and callus formation was better on the half-strength MS medium than on the full-strength medium. This in vitro propagation protocol will be useful for conservation, as well as for mass propagation.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.371-379
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• 2010

Crimson clover (Trifolium incarnatum), hairy vetch (Vicia villosa) and rye (Secale cereale) are common leguminous cover crops. Because they contain water-soluble allelopathic substances that show a variable level in tissue depending on growth stage of the plants, the weed inhibition effects are dependent on the growth stage of cover crops. This study investigated the allelopathic effects of crimson clover, hairy vetch and rye on soybean, radish, oilseed rape and lettuce seeds germination and seedling growth. We used extract that were prepared from the shoots of crimson clover, hairy vetch and rye at different growth stages, vegetative growth stage, flowering stage, and fruiting stage. Applications of aqueous extracts from three growth stage of cover crops strongly affected to oilseed rape and lettuce seeds germination but the treatment resulted in a slight inhibition of the germination in soybean and radish. Radical length was more sensitive to aqueous extracts than seed germination rate. Especially, three cover crops extracts at vegetative growth stage highly inhibited seedling root growth of oilseed rape and lettuce by over 80% and 90% respectively. Furthermore, the $GR_{50}$ values were lowest in the treatment of extracts from vegetative growth stage and the level of phenolics was decreased by the order of vegetative growth stage, flowering stage and fruiting stage.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.135-139
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• 1998

Reciprocal interspecific hybrids between N. glauca(2n=24) and N. langsdorffii(2n=18) were obtained by intercrossing. One hundred percent of F$_1$ seeds was produced from intercrossing of N. glauca $\times$ N. langsdorffii, whereas the frequency of F$_1$ hybrid seed formation from N. langsdorffii $\times$ N. glauca was very low. However, all the hybrid seeds were germinated well and then grown to normal plantlets. All the plants of F$_1$ hybrids have chromosome number of interspecific hybrids (2n=21). From observation of morphological characteristic, the structure of petrol, leaf, flower, and the morphology of pollen have characteristics of F1 hybrid. Spontaneous tumors (genetic tumor) were formed from each F$_1$ hybrid; the genetic tumor arose at the reproductive phase when the maternal type of F$_1$ hybrid came from N. glauca, while the genetic tumor arose only after reproductive phase when the maternal type of F$_1$ hybrid came from N. langsdorffii. The genetic tumor actively proliferated on hormone-free medium and produced numerous teratoma shoots. In addition, normal leaf or stem explants of F$_1$ hybrid produced calli on hormone-free medium after 15 days of culture, the calli produced new numerous teratoma shoots after 30 days. The frequency of teratoma shoot formation from rnterspecific hybrid was higher in the N. glauca $\times$ N. langsdorffii than in the N. langsdorffii $\times$ N. glauca. Root development from the teratoma shoots was hardly obtained. Teratoma shoots without roots in vitro can form genetic tumor at the vegetative growth phase after tissue culture.

• Journal of Korean Society of Forest Science
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• v.46 no.1
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• pp.21-28
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• 1980

Strobilus initiation in grafted, 18-year-old slash pine (Pinus elliottii var. elliottii) in a seed orchard was examined in relation to morphological and anatomical characteristics of shoots. Needle weight (total fresh weight of needles per shoot produced during the current growing season) was the most closely related single variable to the number of female flowers produced the following year ($R^2=0.41$). The number of female and male strobili (per shoot) produced the following year was positively and negatively correlated, respectively, with the total weight of current-year needles per shoot. A transition from male to female flowering was associated with increasing vigor (number of needles) of the shoot. Vegetative buds in the upper parts of the crown of poor-flowering trees showed more advanced growth of vascular tissues compared with female-or male-producing buds, indicating a strong favor for vegetative growth.

• Korean Journal of Plant Resources
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• v.14 no.1
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• pp.53-59
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• 2001

This study was carried out to investigate mass propagation technique by using seed and vegetative propagation of Kalopanax pictus Nakai. For developing seed propagation, seed stratification and 1$0^{\circ}C$ after-ripening treatment induced embryo growth within 1 weeks, resulted in increasing germination rate of seeds up to more than 65% when planted. The softwood cutting using one year old shoot increased rooting rate to 69% whereas more than 1 year old shoot looked like inappropriate for cutting propagation. In the cutting timing, the rooting rate on June, 13 cutting of the first growth shoot was the highest, followed by June 20 and July 4. The most efficient cutting timing seemed to be the middle of June. When cutted shoots were soaked for 30 minute with IBA and NAA 1000mg.$L^{-1}$, rooting rate was increased above 70%. As the concentrations of plant hormone were increased above 2000mg.$L^{-1}$, the rooting rate was slowly decreased.

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.281-286
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• 2007

Gibberellins are growth hormones that play a pivotal role in the growth and development of plants. Present investigations were carried to check the effect of nitrogen(N) and silicon(Si) on bioactive $GA_1$ and its immediate precursor $GA_{20}$ at different growth stages of two rice cultivars with different maturity traits. It was observed that the endogenous bioactive $GA_1$ level gradually increased during vegetative stage and anthesis stage of both Junghwabyeo(early flowering cultivar) and Daesanbyeo(late flowering cultivar). However, the $GA_1$ and $GA_{20}$ content start decreasing during the seed filling stage in both rice cultivars, which indicated a possible relationship of bioactive $GA_1$ and floral development. Our results also confirmed that early 13-hydroxylation pathway was operated at all developmental stages of rice plant. Variation in the levels of the endogenous gibberellins in rice shoots were measured by GCMS-SIM using $^2H_2$-labeled gibberellins as internal standards. Combined application of N and Si enhanced growth parameters and reduced lodging index of both rice cultivars. It was thus concluded that the level of physiologically active $GA_1$ increased during vegetative and early reproductive stage, but starts declining at seed filling stage.