• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.195-200
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• 1998

Callus induction from leaf and stem explants of Arabidopsis thaliana was successfully obtained when leaf explants were cultured on MS medium containing 2.0 mg/L 2,4-D in the dark and also, when stem explants were cultured on CP medium containing 0.5 mg/L 2,4-D and 0.1 mg/L BAP. Explant-derived sliced calli were suspension-subcultured every week in CP liquid medium with 0.5 mg/L 2,4-D and 0.1 mg/L BAP in the dark, and shoot-forming cell clusters of nodular, pale yellow and knobby type were selected after 7-8 weeks of culture. Shoots were initiated from the green spots of the selected shoot forming calli cultured on MS regeneration medium containing 0.05 mg/L IAA, 7.0 mg/L 2-iP and 30 g/L sucrose under continous illumination for four weeks. Shoot regeneration frequency (calli regenerating at least one shoot) was more than 50%. For plant regeneration, excised shoots were trnasferred to hormone free medium for root initiation after 4 weeks of culture. The regenerants were bolting after 2 weeks of culture and formed in vitro flowering buds within bracts after 4 weeks of culture.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.332-335
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• 2015

Taphrina wiesneri, a pathogen of cherry witches' broom, is highly pathogenic to Prunus yedoensis Matsumura which are widely planted in parks and streets in South Korea. In order to control the disease, it is crucial to know the life cycle of the fungus. We attempted to detect the fungus tentatively overwintering in shoots and branches of cherry trees both having witches' broom and healthy before flowering and leafing in spring using PCR with species-specific primer set (TwITSF and TwITSR). Genomic DNAs were extracted from the symptomatic and the asymptomatic shoots or branches. Results indicated that T. wiesneri is present in leaf buds and inner bark not only in symptomatic branches but also in the asymptomatic branches in diseased trees. However, the fungus was not detected in flower buds of the symptomatic trees and any samples of healthy trees.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.38-49
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• 2013

Prohexadione-calcium (Pro-Ca), ethephon and transient water stress were evaluated in a factorial design, as potential inhibitors of early-season shoot growth of high density orchard management of apple (Malus domestica Borkh.) trees. In the experiment, water stress was imposed to one-half of the 7-year-old 'Golden Delicious'/M.9 apple trees in each of 5 blocks, by stopping irrigation for 3 weeks between 35 and 56 days after full bloom (AFB). Within each whole unit, the following Pro-Ca and ethephon treatments were randomly allocated at $2{\times}2$ factorial: a) 0 or 250 $mg{\cdot}L^{-1}$ a.i. Pro-Ca applied at 28 days AFB and b) 0 or 300 $mg{\cdot}L^{-1}$ a.i. ethephon applied twice (35 and 71 days AFB). All trees were hand thinned to king flowers prior to treatments. Vegetative shoot growth was markedly reduced by Pro-Ca, with its effect being obvious within 14 days after application, while ethephon and water stress treatments were less effective. Pro-Ca had no effect on fruit set and yield but slightly increased fruit size. Ethephon substantially reduced the fruit size and yield but had no effect on fruit set. Water stress reduced fruit set, fruit size and yield. With regard to fruit quality, Pro-Ca did not influence fruit shape, flesh firmness and soluble solids contents (SSC) but slightly reduced titratable acidity. Ethephon had no effect on fruit shape but increased firmness, SSC and acidity, while water stress did not influence these fruit quality attributes. Dry weight of dormant spur buds was reduced by both Pro-Ca and water stress, while increased by ethephon. The larger dormant buds led to the larger spur flowers at the tight cluster stage the following spring. Return flowering was promoted only by ethephon, especially on previous season's shoots. There were no significant interactions between Pro-Ca and ethephon or water stress on most variables observed in this study.

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.201-206
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• 2013

BACKGROUND: Kiwifruit, which was introduced to Korea in late 1970s, is a warm-temperate fruit tree, whose leaves are easily damaged by wind because of their large size. To produce high quality fruits, efficient windbreak is necessary to protect leaves until harvest. In Korea, typhoons from July onwards usually influence the production of kiwifruit. Damages from typhoons include low fruit quality in the current year and low flowering ratio the following year. This study was conducted to investigate the effect of early defoliation of kiwifruit vines from July to October on the regrowth of shoot axillary buds the current year and bud break and flowering the following year. METHODS AND RESULTS: Scions of kiwifruit cultivar 'Goldrush' were veneer grafted onto five-year-old Actinidia deliciosa rootstocks, planted in Wagner pots (13L) and grown in a rain shelter. Kiwifruit leaves in the proximity of leaf stalk were cut by lopping shears to simulate mechanical damage from typhoon since only leaf stalks were left when kiwifruit vines were damaged by typhoons. Kiwifruit vines were defoliated from July 15 to October 14 with one monthintervals and degrees of defoliation were 0, 25, 50, 75 and 100%. All experiments were conducted in the rain shelter and replicated at least five times. Defoliation in July 15 resulted in a high regrowth ratio of 20-40% regardless of degree of defoliation but that in August 16 showed only 5.8% of regrowth ratio in the no defoliation treatment; however, more than 25% of defoliation in August 16 showed 17-23% of regrowth ratio. In September 15, regrowth ratio decreased further to less than 10% in all treatments and no regrowth was observed in October 14. Percent bud break of all defoliation treatments were not significant in comparison to 64.7% in no defoliation except for 42.1% and 42.9% in 100% defoliation in July 15 and August 16, respectively. Floral shoot in the no defoliation treatment was 70.2% and defoliation of 50% or less resulted in the same or increased floral shoot ratio in July 15, August 16, and September 15; however, defoliation in October 14 showed no difference in all treatments. In flower number per floral shoot, 2-3 flowers appeared in no defoliation and only 1 flower was observed when the vines were defoliated more than 50% in July 15 and September 15. In October 14, contrary to the floral shoot ratio, flower number decreased with increased defoliation. CONCLUSION(S): Therefore, it is suggested that dormancy of 'Goldrush' axillary buds, was started in August and completed in October. The effect of defoliation on bud break of axillary buds the following year was insignificant, except for 100% defoliation in July 15 and August 16. From July 15 to September 15, floral bud ratio was significantly reduced when more than 50% of leaves were defoliated compared to no defoliation. Also, the number of flowers per flower-bearing shoot the following year decreased by less than 50% when compared to no defoliation, and this decrease was more prominent in September 15 than July 15 and August 16.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.27-34
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• 2017

Our aim was to find the effective duration and culture conditions for microspore culture in a genetically variant cabbage (Brassica oleraceae L. var. capitata). We discovered that the '$2{\times}NLN$ medium containing $AgNO_3$ 1 mg/l, sucrose 13%' was most efficient in producing the cabbage embryos. The number of induced embryos was higher in $F_2$ or $F_3$ progeny generation than the $F_1$ hybrid cultivar used as plant materials. Thus, we recommend microspore culturing using progeny plants of failed $F_1$ cultivar. The acquisition ratio of embryos and plants derived from microspore was higher in the early flowering period as compared to the late flowering period. When transplanted in the soil, 71.2% plants developed from the early flowering period, compared to 27.0% from the middle period and 1.8% plants from the late period. Thus, we recommend microspore culture using buds collected during the early flowering period.

• Horticultural Science & Technology
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• v.16 no.1
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• pp.15-17
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• 1998

In order to provide cool night to strawberry plant with cool air and water, an abandoned cool mine was utilized. It's effects on flower induction and fruit yield in 4 different cultivars were examined. After 70 days of transplanting, flowering frequency was below 65% and 100% in control and treatment of night cooling, respectively and regardless of cultivars. Number of flower buds and flower clusters were higher in treated plants compared with the control. Average time until flowering was much less in treated plants. In terms of yield weight and total yield, 'Suhong' was found to be the best cultivar, averaging 24.2g fruit. Cooling contributed to the 6-7 times of increase in total yield within the frame of harvesting times. The fruit were harvested at 80-97 days after transplanting.

• Korean Journal of Plant Tissue Culture
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• v.21 no.6
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• pp.347-351
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• 1994

To measure the time required for ginseng explants to become determined to form flower buds, we cultured zygotic embryos, seedlings, and cotyledonary nodes on MS medium supplemented with BA and GA$_3$of 5 ${\mu}$M each (flower inducing medium, FIM) for various periods and transferred to the basal medium. The explants required a minimum of 10 days on FIM to be determined. Histological observations revealed that the axillary meristem to be fated to develop into flower bud remained in a state of shoot meristem during the first 10 days of culture and differentiated into flower bud after 15 days of culture. We suggest that the in-vitro flowering system described in this study is useful in investigating (a) regulatory element(s) to cause the phase change from the vegetative to reproductive state by comparing predetermined explants with determined ones at the molecular level.

• Korean journal of applied entomology
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• v.53 no.1
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• pp.65-71
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• 2014

Frankliniella occidentalis is attracted to flowers and is a major pest of chrysanthemums. Even when some chrysanthemum plants are not flowering, the ones that have already flowered attract F. occidentalis. Therefore, we investigated the efficacy of chrysanthemum as a trap plant that attract F. occidentalis by using an olfactometer. The numbers of F. occidentalis collected from the flowers of pink, wihte and yellow standard chrysanthemums on a tray with wet paper during the flowering period were 18.4, 56.6, and 52.6 respectively; the numbers of F. occidentalis collected from leaves were 7.8, 16.6, and 15.4 respectively. the numbers of F. occidentalis collected from the buds of pink, white and yellow standard chrysanthemums were 15.2, 45.8, and 41.6 respectively; the numbers of F. occidentalis collected from the leaves were 2, 8.8 and 3.4 respectively. In the Y-tube olfactometer test, the number of F. occidentalis attracted to the 2-way arms of the Y-tube was not significantly different for the yellow, red, violet and white flowers. In the four-choice olfactometer test, when the same visual cues and odor cues were provided, the frequency of F. occidentalis was higher in the yellow (10.7) flowers than in the red (1.3), violet (3.7) and white (2.0) flowers. When visual cues with disturbed odor cues, F. occidentalis preferred yellow (10.0) color over red (3.3), violet (1.3) and white (3.0) colors. When the same visual and odor cues, except for yellow visual cues, were provided, F. occidentalis preferred white (8.3) color over red (4.7), violet (4.7) and yellow (2.0) colors. Therefore, F. occidentalis were attracted to buds before the flowering of chrysanthemum plants and attracted to yellow flowers after the flowering.

• Korean Journal of Medicinal Crop Science
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• v.4 no.3
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• pp.187-192
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• 1996

This study was investigated to know about the stages of flower bud development and the effects of natural and artificial cold treatment on flowering of herbaceous peony. Developing buds of Paeonja lactㅑflora Pall. var. Taebaek were observed since Jun. 17 and peony plants were forced since Nov. 27 in the green house with two weeks interval, and other plants were forced after cold treatment in $5^{\circ}C$ for 1, 2, 4, 6weeks. Differentiation of vegetable part in peony buds was started in early June, and floral part was differentiated in September and their differentiation was continued to shooting in early spring. Buds of peony were sprouted and flowered when it was forced on Dec. 4. Days to shooting were decreased with delay of forcing time from early to late of December, significantly. Two weeks for cold treatment were enough to break dormancy of peony and days to shooting of the cold treated were significantly shorter than the untreated in the same forcing times

• Molecules and Cells
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• v.22 no.1
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• pp.89-96
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• 2006

"Determinate" and "indeterminate" inflorescences in plants are controlled by a single recessive gene, for example, SELF-PRUNING (SP) in Solanum lycopersicum, TERMINAL FLOWER1 in Arabidopsis, CENTRORADIALIS in Antirrhinum, and CENTRORADIALIS-like gene in tobacco. Pepper (Capsicum annuum L.) is an indeterminate species in which shoots grow indefinitely. In this study, we cloned and characterized the pepper SP-like gene (CaSP). RT-PCR revealed that the CaSP transcript accumulates to higher levels in floral buds than in other organs. Comparison of genomic DNA and cDNA sequences from indeterminate and determinate pepper plants revealed the insertion of a single base in the first exon of CaSP in the determinate pepper plants. CaSP is annotated in linkage group 8 (chromosome 6) of the SNU2 pepper genetic map and showed similar synteny to SP in tomato. Transgenic tobacco plants overexpressing CaSP displayed late-flowering phenotypes similar to the phenotypes caused by overexpression of CaSP orthologs in other plants. Collectively, these results suggest that pepper CaSP is an ortholog of SP in tomato.