• Horticultural Science & Technology
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• v.33 no.1
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• pp.31-38
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• 2015

This study was carried out to investigate the relationship between endogenous polyamines (PAs) and floral bud differentiation in chrysanthemum (Chrysanthemum morifolium). In this study, PA content (free, bound, and conjugated) in apical buds, leaves, and roots changed appreciably during floral bud differentiation. PAs accumulated during series of processes such as floral induction, differentiation of floret primordia, and crown formation in apical buds; changes in PAs in apical buds may have a relationship with those in leaves and roots. The levels of free PAs and conjugated PAs [putrescine (Put) and spermine (Spm)] in apical buds rapidly increased during the initiation stage of floral bud differentiation, while free and conjugated spermidine (Spd) reached their highest levels at the stage of floret primordium differentiation. In the free, conjugated, and bound PA fractions, the changes in Spm content were negligible compared to those of Put and Spd throughout the experiment. These findings indicate that PAs participate in regulating the process of flower bud differentiation in chrysanthemum.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.3
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• pp.310-323
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• 1989

This study was carried out to find out the difference of ripening and growth characteristics among the different florets in same panicle. There were 2 different transplanting date (May 25 and June 10) and 6 varieties were used. Physiological ripening period, ripening speed, 1000 grain weight, germination speed and grain quality were studied among the different florets (1, 5 and 8 days after heading) in same panicle. Physiological ripening period was long in late transplanting, late flowering floret, and late varieties by 3-9 days in Japonica. Ripening speed and 1000 grain weight were high in early transplanting and early flowering florets. There was positive correlation among the ripening speed, 1000 grain weight and a average temperature but negative correlation between the ripening and physiological ripening period. Germination speed was excellent in early flowering floret after heading. There was difference in amylose content within varieties and different flowering grains and there was significant correlation between grain quality and meteorological factors in some varieties.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.812-819
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• 2015

Gladiolus is one of the most popular cut flowers in the world floral market and is highly attractive to consumers. The production of poor-quality gladiolus spikes is one of the most important hurdles to obtaining high prices for this crop. The main objectives of this study were to improve the quantitative characteristics of gladiolus spikes, to increase propagule production and to enhance chemical constituent levels in leaves to help improve plant growth. We performed foliar application of bioregulators, including polyamines (putrescine and spermine) and vitamins (ascorbic acid and thiamine), at different concentrations (0, 0.1, 0.4, 0.7 and 1 mM) to gladiolus plants at the three leaf, five leaf and slipping stages. Application of 1 mM putrescine was the most effective treatment, with prominent effects on economically important spike traits including spike length (55.53 cm), spike diameter (7.53 mm), florets per spike (13.99), first floret diameter (9.66 cm) and first floret weight (4.90 g), followed by spermine treatment. The 1 mM putrescine treatment also had positive effects on corm-associated traits including corm diameter and corm weight, with values of 4.57 cm and 26.16 g compared to 3.47 cm and 17.16 g in control plants, respectively. The contents of chemical constituents in leaves, including total chlorophylls ($8.06mg{\cdot}g^{-1}$), total carotenoids ($1.66mg{\cdot}g^{-1}$), total soluble sugars ($4.75 mg{\cdot}g^{-1}$) and phenolics ($0.89mg{\cdot}g^{-1}$) increased in response to foliar application of 1 mM putrescine compared to the control. Ascorbic acid and thiamine also had positive effects on various plant morphological traits and chemical constituents in leaves compared to control plants, but the growth-promoting effects of polyamines were more pronounced. Hence, applying polyamines to gladiolus leaves will help improve spike production and increasing propagule (cormel) yields.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.641-644
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• 2011

A new standard red color gerbera (Gerbera hybrida Hort.) 'Red Auction' was developed from a cross of '01-120-195' and 'Misty red' followed by seedling and line selections at the Flower Research Institute, Gyeongsangnam-do Agricultural Research & Extension Services (ARES) in 2008. Characteristics trials were conducted three times from 2006 to 2008. 'Red Auction' has semi-double type in good harmony with red color (RHS 45-A) ray floret and a good stable flower shape and strong peduncle. Its vase life was 11.3 days. The average yield of 'Red Auction' was 48.8 flowers per plant a year in greenhouse yield trials carried out from 2006 to 2008. This cultivar registered for commercialization in 2010.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.1
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• pp.84-92
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• 1985

This experiment was carried out to study the morphological traits, yield and yield components of barley cultivars - Kangbori, Olbori and Suwon 18 - on different seeding dates. It appeared generally rapid development of young spike from late stage of floret differentiation (X stage) to complete it at heading stage. Young spike appeared more influencials by the different seeding dates rather than years and cultivars. Stem started the development from late stage of spikelet differentiation (VII stage) to early stage of floret differentiation (IX stage), indicating the continuing development from basal to upper internodes. Number of spikes per unit area showed more effect in seeding date rather than cultivar and year. However, number of kernels per spike and 1,000 kernel weight affected more due to years rather than cultivar and seeding date. It was significantly difference in grain yield according to different seeding dates.

• Journal of Life Science
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• v.16 no.4
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• pp.699-703
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• 2006

Maize (Zea mays L.) is a monoecious plant, which separates male (tassel) and female (ear) floret that evolved into increasing heterogeneity. In each floret, male or female, bears both one pistil and three stamens primodia before diverged to unisexual state. When diverged to tassel, pistil cell death occurs in the pistil primodium, which is mediated by TASSELSEED genes. In contrast, cell protection occurs in the ear pistil from TASSELSEED-mediated cell death, which is mediated by SILKLESS1 gene. On the other hand, cell cycle arrest occurred for a long time in the ear stamens and then the stamens eventually dye. The cell cycle regulating genes such as CYCLIN B and WEE1 are involved in this process. Furthermore, the temporal and spatial regulation of gibberellin biosynthesis may cause cell cycle block in arresting stamen cells. This review describes the cell death, cell protection, and cell cycle arrest mechanism during maize sex determination process at the molecular, cellular and developmental biology, and genetic levels.

• Korean Journal of Medicinal Crop Science
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• v.28 no.4
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• pp.298-309
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• 2020

Background: Safflower (Carthamus tinctorius L.) is a useful medicinal and oil crop in Korea. However, when safflower is cultivated, the flowering period overlaps with the rainy season, and seed maturation is poor. Therefore, this study aimed to use basic research data to develop superior varieties using agronomic characteristics and crossing method. Methods and Results: A total of 34 safflower germplasms were sown and their agronomic characteristics were investigated. Based on these investigations, the cultivar 'ui-san-hong-hwa' was selected as the mother plant, and 'Myanmar safflower' (Hsu Pan) was selected as the father plant. In addition, we developed a floret-protecting cap to cover florets after emasculation during the artificial crossing. When florets were protected by the cap, the seed setting rate increased in comparison to that in the non-covered florets. Conclusions: Agronomic characteristics can contribute to developing suitable varieties. The results suggest that the protection cap will be helpful in breeding without the floral organ drying. This study contributes an efficient breeding method to develop new safflower varieties.

• Horticultural Science & Technology
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• v.29 no.1
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• pp.77-80
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• 2011

A new bi-color mini gerbera (Gerbera hybrida Hort.) 'Sun Cap' was developed from a cross of '99-ga-2' and '99-na-3-1' followed by seedling and line selections at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services (ARES) in 2007. Characteristic tests were conducted three times from 2004 to 2007. 'Sun Cap' has single type in good harmony with bi-color (Red/Yellow, RHS 45-B/9-A) ray floret and green center. It has good stable flower shape and strong peduncle. Its vase life was 13.5 days. The average yield of 'Sun Cap' was 102.6 flowers per plant a year in greenhouse. Yield trials were carried out from 2004 to 2007. This cultivar was registered for commercialization in 2009. 'Sun Cap' would be cultured under greenhouse condition in Korea.

• Journal of Plant Biotechnology
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• v.7 no.1
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• pp.37-43
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• 2005

Explants of button daisy were screened for their regeneration potential and transient GUS gene expression. Medium containing MS salts minerals and $B_5$ vitamins supplemented with $0.1\;\cal{mg/L}$ BA and $0.1\;\cal{mg/L}$ TDZ showed the best regeneration. Disc florets and receptacles were the most responsive explants in regeneration and transient gene expression respectively. Regenerated plants were successfully rooted and established in the green-house conditions. Infection and co-cultivation of explants with Agrobacterium tumefaciens containing pCAMBIA 1301 resulted in transient GUS foci. Among the different explants, receptacles showed the highest percentage of transient GUS gene expression. Enzymatic and molecular analyses of transformed calli confirmed the integration of GUS gene.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.539-542
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• 2009

A new gerbera variety "Pink Swan" was released by the National Horticultural Research Institute (NHRI) in 2007. A cross was made between "Royal" with orange and single and 'Himalaya' with white and semi-double in 2004. After investigation of the characteristics for 4 years (from 2004 to 2007), it was selected specially for the use of cut-flower. "Pink Swan" is a vigorous medium-sized cultivar with pink (RHS R48D), yellow green center and semi-double. The average flower diameter is 10.6 cm. And inner ray floret and disc diameter is 5.99cm and 1.83cm, respectively. It produces a large yield with continuous supply of flowers and has adequate peduncle height. We believe that "Pink Swan" has a great potential for expanding cultivated area of domestic gerbera cultivar and increasing farmers-income.