• Horticultural Science & Technology
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• v.33 no.6
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• pp.923-931
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• 2015

This study was conducted to investigate petal pigmentation and the expression patterns of anthocyanin-related genes in bicolored roses 'Pinky Girl' treated with temporal heat stress (THS). Cyanin accumulation in petals was correlated with floral bud development and started rapidly as floral buds began to open, defined as the $4^{th}$ stage of floral bud development ($S_4$). This stage seems to be most susceptible to petal pigmentation. The total of cyanin pigmentation at blooming was significantly decreased (by 45.5%) with exposure to THS ($39/18^{\circ}C$ for three days at $S_4$) in comparison with control. Meanwhile, the expression of anthocyanin-related genes such as CHS, CHI, F3'H, DFR, ANS, 3GT, and 5GT was relatively promoted by THS. Only F3H was less expressed (by 26.7%) with THS treatment; thus, F3H could be a key gene for bicolor promotion in 'Pinky Girl' among anthocyanin-related genes. Overall, the expression pattern of the most anthocyanin-related genes did not match the trends of cyanin pigmentation in petals. These results suggest that floral pigmentation could be associated with other mechanisms related to anthocyanin biosynthesis such as post-translational effects and regulatory genes.

• Journal of Sericultural and Entomological Science
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• v.30 no.1
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• pp.1-7
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• 1988

Flower buds of the mulberry(Morus alba L., Morus bombycis Koidz.) were cultured under different conditions such as basal media, and various concentrations of plant growth substances. Effects of the culture conditions on growth of the buds and organ regeneration were investigated and the result obtained are as follows: Murashige and Skoog(M.S.) medium was more effective on budding and growth of female(Keomseolppong) and male(Kaeryangppong) flower buds isolated directly from branches, compared to Greshoff & Doy(G.D.) and Wolter & Skog(W.S.) media. The growth of the female buds was promoted at higher concetration of benzyl amino purine(BAP) i.e., 2.0ppm. The female and male buds cultured after cuuting for seven days showed better growth than those without cutting treatment. The females and the males bloomed to form healthy stigmas and anthers, respectively, when cultured on M.S. media containing high Kinetin with low concentration of indole acetic acid(IAA).

• Horticultural Science & Technology
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• v.32 no.5
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• pp.623-627
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• 2014

Curcuma alismatifolia is becoming popular for cut flowers and potted plants due to its long inflorescence with many showy pink flowers. It is propagated by rhizomes and inflorescences that are similar to those of lotus. However, initiation of inflorescence development of each bract and flower has not been investigated. Therefore, this experiment was conducted to study the inflorescence development of Curcuma alismatifolia 'Chiangmai Pink' by scanning electron microscopy (SEM). When new shoots grew to 15-20 cm in a greenhouse at $25^{\circ}C$, the first bract initiated with a dome-shaped inflorescence apex, followed by initiation of additional bracts, forming the shape of the flower head. Florets were subtended by the first bract when five to seven bracts were formed. Four to six florets were subtended by each bract. The floret positioned in the center initiated and progressed upward first. When the center florets in the upper bracts were formed, florets next to the center floret subtended by the first bract were formed, and formation of the axillary florets progressed upward in sequential order.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.283-288
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• 2006

Characteristics of the rootstock formation and flower bud differentiation according to sowing time for production of the high quality rootstock in Chicory (Cichorium intybus L.) was investigated. The flower bud initiation was on the 17th of July after sowing in April, the 2nd of July after sowing in May, the 30th of July after sowing in June and the 1st of October after sowing in July. But they didn't differentiate after sowing in August and September. The days required from germination to flower bud initiation and accumulated temperature depended on the weather. If the outside air temperature was high, the days required were less, If the outside air temperature was low, the days required were greater, the accumulated temperature was similar to the days required in this experement, too. The rootstock sown from April to July wasn't good enough to be use because the flower bud differentiation was generated before harvestable weight. the weight of rootstock was sown in September wasn't heavy enough in weight because the outside air temperature was too low for it to grow well. The plant grows slow and steady through out winter. The rootstock sown in August was havestable 200g in 90 days after sowing before the flower bud differentiated. The best sowing time for the production of high quality rootstock of Chico in the climate of Korea is researched to be August.

• Journal of Bio-Environment Control
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• v.2 no.2
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• pp.136-146
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• 1993

In order to study flowering of Chrysanthemum coronarium, several investigations on the daylength, shading, irrigation and plant growth regulator treatment were carried out. As daylength was treated for 12, 14 and 16hrs, flowering was accelerated and plant height was increased. Leaf number, length and width were decreased by the increased daylength. Sensitivity to daylength and flower development were accompanied by the plant growth, especially the effect of long day treatment was appeared remarkably when the number of leaves was more than 8 leaves. The minimum days of long day treatment for flowering was more than 10 days. Flowering was delayed by 65% shading treatment, over irrigation.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.719-727
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• 2010

Reduced irradiance promotes shoot elongation depending on developmental stage and environmental factors and decreases plant quality in $Cyclamen$ $persicum$ Mill. To determine the petiole elongation responses to low irradiance, 'Metis Scarlet Red' cyclamen at different developmental stages [juvenile (5-6 unfolded leaves), transitional (1-3 visible flower buds), or mature (1-3 elongating peduncles)] was grown in growth modules at 60 (low light, LL) or 240 (high light, HL) ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD within the growth chambers at different temperatures [16/12 (low temperature, LT), 22/18 (medium temperature, MT), or 28/$24^{\circ}C$ (high temperature, HT) (day/night)]. In Experiment I, juvenile plants were either kept in an LL or HL module during the entire treatment of 4 weeks or were transferred to the other module at 1, 2, or 3 weeks after treatment in an MT chamber. In Experiment II, juvenile, transitional, or mature plants were moved to the HL module at 0, 3, 6, 9, or 12 days after being placed in the LL module at the MT chamber and grown for 21 days. In Experiment III, transitional plants were moved to the HL module at 0, 3, 6, 9, or 12 days after being placed in the LL module at the LT, MT, or HT chambers. As the exposure duration to LL increased from 0 to 4 weeks or from 0 to 12 days, petiole length and plant height increased at all temperatures and developmental stages. In Experiment I, the exposure to LL during the latter period, rather than the early period, increased elongation rate. In Experiment II, petiole elongation in transitional plants was more sensitive to LL than juvenile or mature plants during the early period of the treatment for 12 days. In Experiment III, petiole length increased with increasing temperature and exposure duration to LL. Petiole elongation rate at HT increased rapidly from the beginning of LL exposure as compared to LT. Increase of $6^{\circ}C$ in temperature had the similar effect to LL exposure for 3 days in petiole elongation. To conclude, transitional cyclamen under higher temperatures responds more immediately to low irradiance and elongates its petioles.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.714-719
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• 2013

The bent peduncle phenomenon (BPP) is known as a kind of physiological disorders found in cut rose plants, which causes the reduction of cut flower yields. As yet unknown mechanisms, however, it has not been easy to find solutions for BPP. To address this challenge, this study was conducted to investigate the characteristics of floral morphology, growth, and endogenous phytohormone level of BPP shoots in cut rose plants (Rosa hybrida L. 'Beast'). Morphological observation confirmed the fact that BPP was accompanied by the early formation and being phyllody of a specific sepal among five sepals, which gave rise to peduncle bending in the upper part of the phyllody with fasciation. Year-round BPP frequency in 'Beast' cultivar was in the range of 5 to 20% with seasonal change, increasing rapidly with an average temperature rise in summer. Except bent peduncle, the BPP shoots appeared to grow normally in terms of speed and size of floral development in comparison with normal. However, carbohydrate distribution to the floral part in BPP shoots was significantly reduced. The level of endogenous IAA (3-Indoleacetic acid) within the floral part in BPP shoots was highly maintained during floral development, in contrast to normal shoots. $GA_3$ contents were not significantly different between normal and BPP shoots. This study indicates that BPP would be induced by a series of courses: abnormally early formation of a specific sepal relative to high temperature, being phyllody of the sepal with fasciation, and continuous supply of endogenous IAA by phyllody.