• ALGAE
• /
• v.25 no.1
• /
• pp.27-35
• /
• 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.

• Journal of Environmental Science International
• /
• v.12 no.6
• /
• pp.659-664
• /
• 2003

The experiment was carried out to investigate the effects of sulfuric acid and nitric acid among the main components of simulated acid rain (SAR) on the growth of vegetative organs and seed germination of Arabidopsis thaliana. The Arabidopsis treated with SAR supplemented with sulfuric and nitric acids, respectively, showed 28% and 30% decrease of shoot and root growth compared to the control plants, and also many necrotic spots on leaf surfaces after SAR treatment were observed. The shoot and root length for plants grown with nitric acid rain was 14% and 17% lower, respectively, compared to the control, whereas those grown with sulfuric acid rain was 24% and 25% lower than control plants. When Arabidopsis seeds were sown in distilled water, germination rate was 100% after 7 days. However, 80% in SAR medium supplemented with sulfuric and nitric acids, 88% in sulfuric acid rain medium and 93% in nitric acid rain medium. The germination abilities of seeds harvested from SAR supplemented with sulfuric and nitric acids, sulfuric acid rain, and nitric acid rain were 73%, 73% and 94%, respectively. Consequently, sulfuric acids showed more inhibitory effects than nitric acids on the growth of vegetative organs as well as germination rates in Arabidopsis.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2005.04a
• /
• pp.6-9
• /
• 2005

Plant biotechnology involving genetic modification has been rather controversial. However, the major issues related to safety are being addressed by continued improvements in technology. Some of the related facts will be highlighted to set the tone for a scientific discussion on the possibilities of using the technology for crop improvement. Our main research interest is to understand the molecular regulation of shoot bud regeneration in plant tissue culture, which is essential for crop improvement by biotechnology. We have isolated and characterized some genes that are associated with adventitious shoot regeneration. These include a MADS-box cDNA (PkMADS1) from paulownia kawakamii, which regulates vegetative shoot development and in vitro shoot regeneration from leaf explants. Another gene we have characterized from petunia codesfor a cytokinin binding protein (PETCBP). Preliminary functional analysis of this gene indicated that this also affects adventitious shoot bud initiation. Also, the antisense suppression of this gene in petunia causedexcessive branching. Results from our work and selected other publications will be used to highlight the possibilities of manipulation of such genes to improve crop species.

• Journal of Korean Society of Forest Science
• /
• v.46 no.1
• /
• pp.21-28
• /
• 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 Environmental Agriculture
• /
• v.41 no.4
• /
• pp.328-334
• /
• 2022

BACKGROUND: The low temperature at flowering period break the balance between vegetative and reproductive growth of apple tree. Summer pruning has been used to control vegetative growth. So, this study was conducted to investigate the effect of summer pruning time on shoot growth and fruit quality of 'Fuji'/M.9 apple trees damaged by the low temperature at flowering period. METHODS AND RESULTS: The following treatments were applied to tree : a) control (no summer pruning), b) pruned 26 June, c) pruned 30 July, d) pruned 28 August, and e) pruned 26 September. The summer pruning significantly increased light penetration and fruit red color by reducing the total shoot growth compared with control. And the summer pruning control the outbreak of apple valsa canker. But the summer pruning at the end of June increased regrowth of shoot and pruning weight compared with the summer pruning at the end of August. The summer pruning at 30 July had the highest fruit weight, but return bloom was the highest in the summer pruning at 28 August. CONCLUSION(S): These results indicated the optimum summer pruning time of 'Fuji'/M.9 apple trees damaged by the low temperature at flowering period were the end of August.

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

• Molecules and Cells
• /
• v.21 no.1
• /
• pp.147-152
• /
• 2006

Most plant organs develop from meristems. Rice FON1, which is an ortholog of Clv1, regulates stem cell proliferation and organ initiation. The point mutations, fon1-1 and fon1-2, disrupt meristem balance, resulting in alteration of floral organ numbers and the architecture of primary rachis branches. In this study, we identified two knockout alleles, fon1-3 and fon1-4, generated by T-DNA and Tos17 insertion, respectively. Unlike the previously isolated point mutants, the null mutants have alterations not only of the reproductive organs but also of vegetative tissues, producing fewer tillers and secondary rachis branches. The mutant plants are semi-dwarfs due to delayed leaf emergence, and leaf senescence is delayed. SEM analysis showed that the shoot apical meristems of fon1-3 mutants are enlarged. These results indicate that FON1 controls vegetative as well as reproductive development by regulating meristem size.

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

• Horticultural Science & Technology
• /
• v.32 no.1
• /
• pp.1-9
• /
• 2014

This study investigated the effects of temperature on the shoot growth and flowering of potted kumquat [Fortunella margarita ( Lour.) Swingle] trees grown in subtropical conditions of I-Lan County in Taiwan. Temperature treatments included T 25-32, T 17-25, T 22, and T 18. The T 25-32 treatment trees were to the day/night temperatures of $25/18^{\circ}C$ for 2 weeks, followed by 28 weeks at $32/25^{\circ}C$. T 17-25 was exposed for 4 weeks to $17/10^{\circ}C$ followed by 26 weeks at $25/18^{\circ}C$. T 22 and T 18 were exposed at $22/18^{\circ}C$ and $18/13^{\circ}C$, respectively, for the entire duration of the experiment. Control trees were placed in a plastic greenhouse under conditions similar to the natural environment. The kumquat trees exposed to high-temperature environment of $32/25^{\circ}C$ showed more frequent and speedy sprouting of new buds, but induced the earlier termination of shoot elongation growth, resulting in decreased vegetative growth. The temperature treatments lower than $22^{\circ}C$ suppressed the new shoot production but increased the shoot growth period, resulting in increased shoot length and diameter. Temperatures higher than $25/18^{\circ}C$ readily induced flowering, with flowering being advanced under the higher temperature conditions such as $32/25^{\circ}C$. However, flowering was substantially inhibited under temperature conditions lower than $22/18^{\circ}C$, indicating the negative role of relatively lower temperatures on flowering of kumquat trees.

• Korean Journal of Plant Resources
• /
• v.31 no.1
• /
• pp.71-76
• /
• 2018

This study was conducted to investigate the effect of shoot twist on fruitfulness and fruit quality of 'Campbell Early' grapevine. Proper pruning and training are essential to produce a good yield of high-quality fruit and to maintain the balance between vegetative growth and fruiting. The most common problem in spur-pruned 'Campbell Early' cultivar is that vigorous buds has low fruitfulness and thereby the shoot become more vigorous the following spring because of lower crop load. Therefore, shoot twists in very vigorous 'Campbell Early' canes (above 10.0 mm) were performed on the third nodes and the $7^{th}$ nodes of each shoot at 7 days before bloom and full bloom, respectively. Sprouting date, blooming date were not significantly different among the treatments while, harvesting date was delayed approximately 3 days. However, number of berries per cluster, cluster weight and fruitfulness were significantly higher in the shoot twist treatment on the third nodes than the control that was topping alone. Combination treatments of shoot twist and topping had an additive effect on increasing cluster weight resulting in higher increase of yield by 12.1 ㎏ per vine. These results indicated that the shoot twist on very vigorous canes of 'Campbell Early' grapevine for well fruitfulness seemed to be very effective.