• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.5-9
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• 1980

With polyacrylamide gel electrophoresis, peroxidase isoenzyme patterns in the terminal buds of grafted, 20-year-old Pinus elliottii trees were compared between abundant-flowering and poor-flowering trees during the period of female flower bud initiation. A total of nine peroxidase bands were observed in the terminal buds. The total amount of peroxidase enzymes in slash pine buds showed no significant difference between the abundant-flowering and poor-flowering trees. However, the fifth band from the gel front was observed in all the samples of abundant-flowering trees throughout the sampling period (July 8 to September 17), while this band was absent in most of the poor-flowering trees.

• Korean Journal of Weed Science
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• v.17 no.2
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• pp.207-213
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• 1997

This study was conducted to correlate changes in plant growth and flowering behavior with inhibition of gibberellin synthesis following application of GA biosynthesis inhibitor. Two sorghum genotypes, wild-type and phyB-1(phytochrome B mutant) which grow fast and flowers early relative to the wild-type, were used. Both growth and floral initiation of these two genotypes were greatly affected by ancymidol concentration increased. However, these growth inhibition and delayed flowering are almost completely overcome by simultaneous applications of 31.6ppm $GA_3$. The ability of $GA_3$ to reverse the effect of the inhibition on both growth and floral initiation in sorghum suggests a role for native GAs in sorghum flowering. This result was contrast to the fact that in some long day plants GA biosynthesis inhibitors will inhibit shoot elongation but not floral initiation. In sorghum, inhibition of vegetative growth by GA biosynthesis inhibitor is accompanied by a delay in flowering. Ten ppm of ancymidol treatments drastically reduced all early-13-hydroxylation pathway GAs($GA_{12}$, $GA_{53}$, $GA_{19}$, $GA_{20}$, $GA_3$, and $GA_8$) levels.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.726-731
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• 2013

Experiments were conducted to evaluate the effect of low temperature-darkness treatment on floral initiation in four kinds of Korean strawberry cultivars. Mother plants were planted on March 29 and daughter plants were raised for the experiment. Temperature treatment was done for 7, 14, and 21 days keeping $13^{\circ}C$ in cooling storage from August 29, September 5 and September 14 to September 21. After the treatment, flower bud initiation was examined by a microscope, and the seedlings were transplanted on hydroponic system with Yamazaki's strawberry solution of EC $0.8dS{\cdot}m^{-1}$ to check the flowering. 'Ssanta' and 'Maehyang' showed early flower bud initiation in 7 days treatment than 'Seolhyang' by microscope check. 'Ssanta', 'Daewang', and 'Maehyang' showed early flower bud initiation in 14 days treatment than 'Seolhyang'. There were no differences among the treatments in 21 days treatment. Percentage of flowering of 'Seolhyang' and 'Maehyang' by low temperature-darkness treatment didn't show any difference but 'Daewang' and 'Ssanta' showed high percentage of flowering. It suggested that low temperature-darkness treatment technique can be use for improving early flowering and yield of 'Ssanta' and 'Daewang' cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.478-482
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• 2001

This experiment conducted to know physiological characteristics and stress effect on different growth stage of soybean by night illumination. Soybean variety, Shinpaldalkong 2, Keumjungkong and Muhankong were treated by night illumination with 20~30 Lux (0.05~0.08W m$^{-2}$ , 0.24~0.36 $\mu$㏖ S$^{-1}$ m$^{-2}$ ) for 15 days at six different growth stage, seedling, pre-floral initiation, post-floral initiation, pod filling and seed ripening stage. Night illumination delayed flowering to 2~8 days compared to control. Delay of flowering by night illumination severely effected at the pre-floral initiation stage. Stem length was increased all the night illumination treatments except the pod filling stage. Number of nodes in Shinpaldalkong 2 and Keumjungkong 1 were increased until before post-floral initiation stage but in Muhankong were increased until after post-floral initiation stage by night illumination treatments. Number of pods were decreased all the night illumination treatments except seedling stage compared with control. Yield decreased all the treatments and severe the loss rate degree showed the order of prefloral initiation, post-floral initiation, seedling and flowering stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.543-547
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• 1995

This study was conducted to light intensity and night interruption on leaf production in perilla. Using two cultivars ; og-dong and Yeup-sil. The present studies were conducted to investigate effect of the light intensity and night interruption for prolongation of vegetative growth by flowering inhibition in the National Honam Crop Experiment Station, R. D. A, Iri, Korea. The results are summarized as followes, varietal differences of days to flower initiation were not significant by the light intensity and night interruption, however differences of days to flower initiation light intensity or night interruption treatment were higly significant. Flowering of perilla was prolongated in high light intensity and in long night interruption. Between the factors treated flowering of perilla was more influenced by light intensity than night interruption. Days to flower initiation of perilla were light intensity(0.5∼1 Lux) in 30 mins night interruption, however 3∼10 light intensity in 60 mins night interruption and 30∼100 Lux light intensity in 10, 30, 60 mins night interruption treatment were not flowering. Plant height, leaf area and dry weight of perilla were the highest in 30∼100 Lux light intensity treatment than in the other treatments. The results would be avaliable establish year-round production methods for low cost of perilla leaf.

• Korean Journal of Plant Resources
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• v.7 no.1
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• pp.63-66
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• 1994

The experiment was carried out to study the bothanical characteristics of Aconitum charmichaeli Sieb. et Zucc in Korea.The results obtained are summarized as follows ; maximum flowering date was 15 Sep. and plantheight was 65cm, stem diameter was 8.7mm, No. of node was 25 and node of flowering initiation was15th.In flowering, No. of anothers were 52 and No. of flowers were 49.In leaf, length and width was same size, lower leaf size was 2-3 times than upper leaf, lower leafarea was 8.4 times than upper leaf.In tuber, No. of tuber per plant was 8, fresh weight per tuber was 25.4g, total fresh weight per plantwas about 200g.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.71-76
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• 1998

To define the relations between endogenous GA levels and growth and flowering in short-day plant sorghum, growth retardant BX-112 was applied to two sorghum genotypes, wild-type and phytochrome B mutant (phyB-1), which grows faster and flowers earlier than the wild-type. BX-112 and $GA_3$ were applied as a soil drench, and plant height, culm length, and date to floral initiation were investigated. Endogenous GAs contents were measured with GC-MS-SIM. BX-112 treatments inhibited shoot growth in both genotypes and drastically reduced $GA_1$ and $GA_8$ levels. With increasing BX-112 concentrations, $GA_1$ concentrations declined linearly, but caused the accumulation of intermediates from $GA_12$ to $GA_20$. This result implies that $GA_1$ is the major active endogenous GA in shoot elongation in a short day plant sorghum. The inhibition of plant growth in both of wild type and phyB-1 by BX-112 was very similar, while BX-112 effects on floral initiation in two types of plants differed significantly. Floral initiation of phyB-1 was not affected by BX-1l2, but that of wild-type was delayed as BX-1l2 concentration increased. Because BX-112 treatment causes accumulation of biosynthetic intermediates between synthetic pathway from $GA_12$ to $GA_20$ and because phyB-1 is altered in GA metabolism in this same region of the early C13-hydroxylation pathway, BX-112 may fail to block flowering of phyB-1.

• Korean Journal of Plant Resources
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• v.31 no.6
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• pp.591-596
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• 2018

This study was conducted to develop gibberellin treatment technique to enhance flower initiation in Aquilegia japonica Nakai & H. Hara. Seedlings were planted in 12cm-diameter pots on October 2016 and grown in green house. Ambient temperature in the green house was set at minimum $15^{\circ}C$ during day and night to suppress flower initiation at cold temperature condition. Two different types of gibberellin, $GA_3$ and $GA_{4+7}$, at 4 different concentration levels 100, 200, 400 and 600 mg/L, were tested in this study. Gibberellin was sprayed first at planting and secondly at 1-week after planting. Ten to fifteen ml of gibberellin was sprayed for each pot. Plant height and petiole length were elongated by both gibberellin types, flowering was more enhanced by $GA_3$ (91.7~100%) compared to of $GA_{4+7}$. However, abnormal flower was less observed in $GA_3$ treatment (0~16.7%) than $GA_{4+7}$. Number of flower stalks per plant ranged from 1.9 to 2.5. Number of flowers per plant ranged from 6.8 to 10.3. Differences in flowering characteristics between treatments were statistically significant. Optimal gibberellin treatment to enhance flower initiation in A. japonica Nakai & H. Hara substituting cold treatment was $GA_3$ at the concentration between 400 mg/L to 600 mg/L.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.297-303
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• 2013

This study was carried out to examine the effect of Red LED (660 nm) and fluorescent lamp for night break (NB) treatments of each 3 hours (22:30-01:30), 4 hours (22:00-02:00) and 5 hours (21:30-:02:30) per day for 53 days on flower bud initiation and growth in Chrysanthemum cv. 'Baekma' and cv. 'Jinba'. The days to flower budding after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (21.0 days) and 5 hr (20.5 days) NB, and it was shorter at Red LED 3 hr (14.2 days). The days to flowering after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (54.0 days), 5 hr (53.5 days) NB, and Red LED 5 hr (53.3 days), and it was shortest at Red LED 3 hr (50.2 days) NB treatment among all treatments. The days to flower budding after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (20.6 days) and was shorter at Red LED 3 hr (14.1 days) among all treatments. Similarly, the days to flowering after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (55.3 days) and was shortest at Red LED 3 hr (50.2 days) among all treatments. Therefore, inhibition of flower bud initiation was the most effective under fluorescent lamp 4 hr treatment. The length of cut flower of 'Baekma' was increased by fluorescent lamp 4 hr, 5 hr, and Red LED 5 hr, but of 'Jinba' was longer at LED 4 hr and 5 hr treatment. The weight of cut flower of 'Baekma' was heaviest at fluorescent lamp 5 hr treatment and was at Red LED 5hr treatment for 'Jinba' even though there was not statistically significant difference between 'Baekma' and 'Jinba'. Consequently, under fluorescent lamp 4 hr for night break was the most effective on flower bud initiation, flowering inhibition and cut-flower characteristics in 'Baekma' and 'Jinba'.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.236-242
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• 2012

We investigated the influences of night interruption (NI) and night temperature on flowering and flower coloration in Cymbidium. Cymbidium 'Red Fire' and 'Yokihi' were grown under a 9 hours photoperiod (control), a 9 hours photoperiod with NI at a low light intensity (LNI) of 3-7 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, or a 9 hours photoperiod with NI at a high light intensity (HNI) of 120 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for four hours (22:00-02:00 HR) for 16 weeks during the reproductive growth stage (Experiment 1). Thirty month-old Cymbidium 'Red Fire' plants with initiated flowering buds were placed in four different growth chamber with night temperature set points of 6, 9, 12, or $15^{\circ}C$ for 16 hours (18:00 to 09:00 HR) and a daytime temperature of $25^{\circ}C$ (Experiment 2). In Experiment 1, the numbers of visible buds and flowers increased, and time to flowering decreased in both the LNI and HNI treatments, as compared to the control in both cultivars. Red color in Cymbidium 'Red Fire' increased by both LNI and HNI, as evidenced by an increased $a^*$ in plants grown under these conditions, relative to those grown under the control condition. Number of days to visible buds at 9-$15^{\circ}C$ ranged from 31-34 days, as compared to 39 days at $6^{\circ}C$ in Experiment 2. Although as the temperature increased days to flowering decreased when the plant was grown at $15^{\circ}C$ as compared to 6, 9, or $12^{\circ}C$, the red color ($a^*$) also decreased. The number of flowers and percent flowering increased when the night temperature was maintained higher than $9^{\circ}C$. Therefore, NI treatment and maintaining the night temperature at approximately 9-$12^{\circ}C$ during the winter season after flower spike initiation in the reproductive developmental growth stage improve flower quality and controls flowering time.