• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.366-372
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• 2009

This study was conducted to develop new lines expressing the characteristic of early flowering by introducing MdMADS2 gene in chrysanthemum (Dendranthema grandiflorum (Ramat.) Kitamura) ‘Zinba'. Transformation of chrysanthemum was conducted by Agrobacterium tumefaciens LBA4404 harboring the binary vector containing MdMADS2 controlled by double CaMV 35S promoters. Ninety three shoots were regenerated from 1,463 leaf segment explants cultured on the first selection medium (MS basal salts + 1.0 mg/L BA + 0.5 mg/L IAA + 10 mg/L kanamycin + 400 mg/L cefotaxime, pH 5.8) after co-cultivation, and 20 out of the 93 shoots rooted on the second selection medium containing 20 mg/L kanamycin and 400 mg/L cefotaxime. Many escapes (98.6%) were removed on the selection stage for rooting. Nineteen lines were confirmed as transgenic plant with transgene by PCR analysis. Six transgenic plants flowered 2-11 days earlier than non-transgenic plant without big change of phenotype, and especially, 3 (Mo-7, Mo-11, Mo-17) out of 6 transgenic lines showed a significant reduction in days to flowering compared to non-transgenic plant. Introduction and expression of MdMADS2 gene in them were confirmed by Southern and real-time PCR analyses, respectively.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.564-577
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• 2017

We investigated whether external environmental factors acted as a trigger for flowering in the draft bamboo (Sasa borealis (Hack.) Makino) blooming area of Mt. Baekwoon located in Gwangyang, South Jeolla Province. We then considered the cause for flowering, flowering patterns and life history strategies of the draft bamboo based on the investigation. There were no differences in soil, physical conditions, and light amount between the draft bamboo flowering and non-flowering areas. The precipitation and temperature of the areas in Korea and Japan where it blossomed from 2014 to 2017 were similar to the normal year values (for the past 30 years). Moreover, most of the draft bamboo died after flowering on a large scale, but some did not, or some culms were developed again. In other words, the draft bamboo bloomed simultaneously regardless of external environmental factors, and most of the culms were dead, but some were left alive. Therefore, it is considered that the flowering is triggered by the specific genes (referred as to clock genes) expressed periodically by a biological clock rather than the external environmental factors. Meanwhile, the draft bamboos generally bloom on a large scale by synchronizing with other ones in the distance but may also bloom several times separately on a small scale. It may be a kind of an insurance system established to disperse the risk of failed sexual propagation when flowering once in a lifetime. The results reveal that the long-period monocarpy of the draft bamboo has been strengthened to optimize the sexual propagation to overcome the increased environmental instability caused by the expansion of distribution of tropical bamboos and bamboo species to the temperate regions.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.51-56
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• 2001

This study was carried out to research the effect of nutrient composition and GA4＋7 on growth, flower quality and bulb development in special hydroponics of cut tulip. Flowering of 'Cassini' was markedly accelerated by standard+GA4＋7, K200＋GA4＋7, N250＋GA4＋7 treatment, last internode was increased by N250 as compared with other treatment. For 'Christmas Marvel', flowering was promoted by K250＋GA4＋7, last infernode and total length were also increased with K250＋GA4＋7 as compared to other treatment. For 'Golden Apeldoorn', flowering was accelerated by K200＋GA4＋7, last internode was increased with N300＋GA4＋7 treatment and total length was increased in N250＋GA4＋7 treatment as compared with the standard plants. Bulb weight and number of 'Cassini', 'Christmas Marvel'and 'Golden Apeldoorn' were decreased by GA4＋7 as compared to non-treatment, and bulb diameter was not affected by GA4＋7.

• Journal of Korean Elementary Science Education
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• v.26 no.1
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• pp.41-48
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• 2007

The purpose of this study is to examine how many plant names elementary school children how, and what kind of criteria they use for classifying these plants. The sample involved 926 students from the 2nd, the 4th, and the 6th grades dwelling in one urban, three suburban, and six rural areas. Their level of perception on the name of plants increased in correlation to the elevation of the grade level. However, different patterns of increases were shown depending on the local environments in which they live. The most well-known plant names for students were the rose of Sharon, the rose and the pine tree. The students mostly classified the plants using the following criteria such as 'with or without flower' and 'edible or inedible' regardless as to whether they had prior loaming experience of plant classification. 65.3% of the 6th graders correctly grouped 5 kinds of plants into the flowering and the non-flowering plant categories at the 1st level of classification. However, only 17.9% and 7.7% correctly divided the flowering and the non-flowering plants into two subgroups at the 2nd level of classification respectively. Therefore, their abilities in plant classification was shown overall to be poor. The students living in suburban areas appeared to be harmonized with both the natural and urbanized surroundings and classified the plants more scientifically than those from the urban or rural areas were able to. This suggests that the conception of plant classification by children is affected by the environment in which they live. If children have more opportunities to observe plants in surroundings such as their classrooms and school gardens, it will help them to form the relevant scientific concepts as well as to correct any alternative conceptions related to classification.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.609-614
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• 1997

C-MH(Choline salt of maleic hydrazide, 39％) has been applied on peanut(Arachis hypogaea L.) plant in 1994∼1995 on three different times of 24 days after flowering (DAF), 28 DAF and 31 DAF and on three different levels of 0.2, 0.1. 0.067％, respectively. Main stem length was noticeably retarded by 38∼44％ compared to that of non-treatment. Branch numbers were not changed by C-MH treatments. Ratio of flowering inhibition was 38％ in 0.2％ concentration and 22％ in 0.067％ at 28 days after flowering treatment compared to that of control. Ratio of pure seed was slightly enhanced by 3％ in 28 DAF treatments. Yield productivity was increased by 7％ in 0.1％, at 28 DAF treatment compared to that of non-treatment (3.2MT /ha).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.1
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• pp.23-30
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• 1993

This study was conducted to obtain the fundamental information on antioxidant component as affected by process of grain filling in different plant types of sesame. Sesamin and sesamolin as antioxidant components, oil content and seed weight were investigated for two plant types with different by branching habit. The sesamin and sesamolin contents in grains followed a pattern of increase immediately after flowering in branch type and monocapsule habit than non-branch type and tricapsule habit. But they started to decrease around 45 days after flowering, which oil content and seed weight continued to increase until maturity. The sesamin content increased quickly up from 10th to 40th day after flowering and showed almost maximum at 43th day after flowering. The sesamolin content increased quickly up from 20th to 30th day after flowering and showed almost maximum at 45th day after flowering. The oil content increased quickly up from 20th to 30th day after flowering and showed almost maximum at 47th day after flowering. The seed weight increased quickly up from 20th to 40th day after flowering and showed almost maximum at 48th day. The sesamin content, sesamolin content, oil content and seed weight showed almost maximum at from 43th to 48th day after flowering. So that this period was considered to be of physiological maturity.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.755-757
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• 1999

This study was conducted to investigate the optimum temperature after BA treatments for the indution of flowering in Cymbidium ensifolium 'Tekkotsusosin'. Flowering rate was 90% at $30/25^{\circ}C$ (day/night), 50% at $25/20^{\circ}C$ and the natural condition as control, and non flowering at $20/15^{\circ}C$. Malformation rate of flower shape was at $25/20^{\circ}C$, 4% at $30/25^{\circ}C$, and 9% in the natural condition. The length and number of flowering stalks per plant were most at $30/25^{\circ}C$ treatment. After BA spraying, the lowest air temperature for flowering was assumed to be about $20^{\circ}C$.

• Journal of Ecology and Environment
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• v.41 no.9
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• pp.256-264
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• 2017

Background: The aim of this study was to clarify the relationship between the sexual reproduction and the resource allocation in a natural Polygonatum humile population grown in a temperate mixed forest gap. For this aim, the plant size, the node which flower was formed, the fruiting rate, and the dry weight of each organ were monitored from June 2014 to August 2015. Results: Firstly, in 3-13-leaf plants, plants with leaves ${\leq}8$ did not have flowers and in plants with over 9 leaves the flowering rate increased with the number of leaves. Among plants with the same number of leaves, the total leaf area and dry weight of flowering plants were larger than those of non-flowering plants. The minimum leaf area and dry weight of flowering plants were $100cm^2$ and 200 mg, respectively. Secondary, the flowers were formed at the 3rd~8th nodes, and the flowering rate was highest at the 5th node. Thirdly, cumulative values of leaf properties from the last leaf (the top leaf on a stem) to the same leaf rank were greater in a plant with a reproductive organ than in a plant without a reproductive organ. Fourthly, fruit set was 6.1% and faithful fruit was 2.6% of total flowers. Biomasses of new rhizomes produced per milligram dry weight of leaf were $0.397{\pm}190mg$ in plants that set fruit and $0.520{\pm}0.263mg$ in plants that did not, and the difference between the 2 plant groups was significant at the 0.1% level. Conclusions: P. humile showed that the 1st flower formed on the 3rd node from the shoot's base. And P. humile showed the minimum plant size needed in fruiting, and fruiting restricted the growth of new rhizomes. However, the fruiting rate was very low. Thus, it was thought that the low fruiting rate caused more energy to invest in the rhizomes, leading to a longer rhizome. A longer rhizome was thought to be more advantageous than a short one to avoid the shading.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.438-447
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• 2017

Flowering is one of the most important development traits related to the production of Brassica rapa crops. After planting, a sudden low temperature triggers premature flowering, which leads to a reduction in the yield and quality of harvested production. Therefore, understanding the mechanism of flowering control is important in the agricultural productivity for preventing Brassica rapa crops. Vernalization is generally known as the main factor of flowering in the Brassica plant. However, in the subspecies of Brassica rapa, some accession such as Yellow sarson and Komatsuna display the flowering phenotype without vernalization. Circadian genes, which diurnally regulate plant physiology, have a role for photoperiodic flowering but are related to the regulation of the vernalizarion mechanism. In this report, the 22 B. rapa accession were divided into two groups, vernalization and non-vernalization, and the sequenced circadian gene, BrPRR1s. Among them, the BrPRR1b gene was found to have deletion regions, which could classify the two groups. The PCR primer was designed to amplify a short band of 422bp in the vernalization type and a long band of 451bp in the non-vernalization type. This primer set was applied to distinguish the flowering types in the 43 B. rapa accession and 4 Brassica genus crop, Broccoli, cabbage, mustard, and rape. The PCR analysis results and flowering time information of each crop demonstrated that the primer set can be used as marker to discern the flowering type in Brassica crops. This marker system can be applied to the B. rapa breeding when selecting the flowering character of new progenies or introducing varieties at an early stage. In addition, these results displayed that the circadian clock genes can be a good strategy for the flowering control of B. rapa crops.

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.4
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• pp.78-83
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• 2024

This study was carried out to analyze the effect of changes in the light environment caused by the daylight disturbance on the growth, flowering, and cut flower quality of spray chrysanthemums. The spray chrysanthemum 'Yellow Cap' and 'Pitch PangPang' cultivars for cut flowers were artificially shaded to interfere with 66% of sunlight compared to the non-shading, and then the growing and flowering characteristics, and cut flower yield were investigated accordingly. There was no significant difference in the cut flower yield per unit area between the shading and the non-shading treatments. However, the number of days to flowering was 72.1 days for the 'Yellow Cap' and 65.2 days for the 'Pitch PangPang', which were delayed by 14.1 and 8.9 days, respectively, compared to the non-shading light. In the shading treatment, the flower diameter and the number of flowers also decreased by 10% and 15%, and 30% and 28% for both 'Yellow Cap' and 'Pitch PangPang', respectively. The stem length also decreased by 10% and 20%, the stem diameter by 23% and 37%, and fresh weight by 32% and 33%, respectively. The shading treatment delayed the flowering of chrysanthemums and reduced the growth such as flower diameter, number of flowers, and the length and weight of cut flowers. Based on these results, the daylight disturbance by artificial buildings is expected to reduce the productivity and quality of cut flowers by limiting the light intensity needed for chrysanthemum growth, flower bud differentiation, and flower development. Therefore, further research is needed on the rate of decrease in yield and market value according to the degree of shading to relieve damage to chrysanthemum growers caused by the daylight disturbance.