• Horticultural Science & Technology
• /
• v.33 no.1
• /
• pp.18-23
• /
• 2015

Time-specific responses of flower bud differentiation were investigated in 'Shinko' (Pyrus pyrifolia Nakai) pear grown at different altitudes from July through December 2013 to determine their suitability as scions in a top-grafting system. Flower bud initiation and bud necrosis were monitored on each of three sections of one-year-old shoots: terminal, middle, and basal. Flower bud differentiation s tarted in September in the highlands of the Lishan area, and in J uly in the lowlands of the Zhoulan area. In Lishan, flower bud differentiation was higher in the middle and basal segments; during leaf fall, however, flower bud differentiation occurred rapidly in the terminal segment. In Zhoulan, flower buds began to differentiate from the terminal section of the shoot, and severe flower bud necrosis was noted. In July, flower buds developed normally; however, in early August, some of the buds at the basal segment showed browning. During leaf fall, some flower buds showed symptoms of necrosis with rapid and complete browning. Flower bud necrosis began at the basal segment and progressed rapidly towards middle and terminal sections. Before leaf fall, flower buds fell off when scales swelled. The terminal and middle parts of the current-year shoots, with some flower buds, collected in October or later from the Lishan area could be used as scions for top-grafting of 'Shinko' pear. Each grafting scion was a 3-5 cm shoot with one flower bud. These results suggest that scions from the terminal and middle segments of stems of 'Shinko' pear from the Lishan area can be used as scions whereas those from Zhoulan area show necrosis and might not be suitable as scions.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.535-539
• /
• 2001

To establish the cultural practices of persimmon in heated plastic house, the growth and flower bud differentiation of 4-year old 'Nishimurawase' persimmon tree planted in 80 L pots were investigated. Temperature was kept at above $18^{\circ}C$. The earlier heating induced the earlier flower bud differentiation, while the number of days from bud burst to flower bud differentiation was 70-75 days, which was not affected by the date of heating. The date of flower bud differentiation in 'Nishimurawase' persimmon was May 1, May 21, and June 1 in the plastic house heated from Jan. 15, Feb. 15, and Mar. 15, respectively. The number of flower primordia per bud in the plastic house was 6.2-7.1, slightly fewer than that of 7.8 in the open-field, with the tendency of increasing the number by earlier heating. The days required for the differentiation of the last flower bud primordia from the beginning of differentiation of the first bud were 40-60, and that required for the flower bud differentiation of all buds on the same shoot was 30. The total carbohydrates in shoot increased and the contents of nitrogen decreased, resulting in increased C/N ratio just before flower bud differentiation, and it coincided with the time when the total carbohydates increased above 15%. During two weeks before flower bud differentiaton, The contents of zeatin per 1 g dry matter of shoot drastically increased from $27.2{\mu}g$ to $47.3{\mu}g$, while that of IAA slightly decreased from $188.6{\mu}g$ to $172.4{\mu}g$, and that of GA decreased from $2,225{\mu}g$ to $1,555{\mu}g$.

• Journal of Plant Biotechnology
• /
• v.44 no.3
• /
• pp.229-234
• /
• 2017

Photoperiod is one of the factors affecting productivity of cucumber plant by inducing ethylene hormone production and so triggering flower sex differentiation into female flower. However, only few studies have been perfomed in order to reveal the effect of photoperiod in molecular level in relation to the flower differentiation. Therefore, in this study, Mercy cultivar of cucumber (andromonoecious) was treated with photoperiod of 8, 12, 16 hours of light, while control received no treatment of additional light. Photoperiod of 8 hours was achieved by blocking the sunlight with shade net and 16 hours by giving longer light exposure using white LEDs. Cucumber's flowers were quantified and the apical and lateral shoots were extracted to evaluate the gene profile related to the photoperiod, ethylene production, and female flower differentiation, which were CsACS2, CsETR1, CsCaN, and CsPIF4 using PCR method. Photoperiod of 8 hours affected the production of female flower with average number of 6.7 flowers in main stem and 8.0 flowers in lateral stem, compared to photoperiod of 12 and 16 hours which produced 3.7 and 2.0 flowers in main stem with 7.0 and 11.3 in lateral stem, respectively. In silico studies in this experiment resulted in proposed model of signal transduction that showed the connection between ethylene production and flower differentiation. PCR analysis confirmed the expression of CsACS2, CsETR1, and CsCaN, that was positively correlated with numbers of female flowers in cucumber, but the expression of CsPIF4 that represent photoperiod haven't been confirmed correlated with the ethylene production and flower differentiation.

• Korean Journal of Medicinal Crop Science
• /
• v.23 no.3
• /
• pp.190-197
• /
• 2015

In this study, we tried to offer the possibility of White Hibiscus syriacus L. (WHS) flower extracts as a preventive and improving agent of osteoporosis that bone mass reduction is induced by an decrease of osteoblast involved in bone formation and increase of bone resorption by osteoclast activity. As a results, it was found to have antioxidant activity and contain a flavonoid contents ($47.74 mg/g) of the WHS flower. There was cytotoxicity at more than $250{\mu}g/m{\ell}$ concentration of WHS flower extract of RANKL-induced osteoclast in RAW264.7. There were no significant inhibited TRAP activity in the WHS leaf and stem. However, it was confirmed that it is significantly inhibited the differentiation activity of osteoclasts in 50 and $100{\mu}g/m{\ell}$ concentration of cells of stability levels of only WHS flower extracts (p < 0.01). The WHS flower prominently inhibited RANKL-induced osteoclast differentiation activity by decreased calcitonin receptor and TRAP mRNA (p < 0.01). These results indicate that of osteoclasts differentiation activity is inhibited by protection of oxidative stress due to the antioxidant activity of the WHS flower. Therefore, suggesting the WHS flower may be a presents the possibility as a preventive and therapeutic agents for osteoporosis.

• Korean Journal of Plant Resources
• /
• v.8 no.3
• /
• pp.265-274
• /
• 1995

Characteristics of vegetative spur leaf, spur bud, fruiting supr leaf and flowering in relation to canopy position was investigated on order to promote better spur bud and flower bud differentiation on Citrus junos. There was no difference in vegetative spur leaf characteristics among directions. Vegetative spur leaf number and leaf area showed no difference between top and bottom position. There was no difference in spur bud size among directions, but spur bud at top was larger than that at bottom. Specific leaf weight of vegetative spur was mostly influenced by light interception, and leaf dry weight per spur average leaf dry weight, spur bud length and diameter had also a very high correlation with light interception rate. Shading and GA treatment in spur bud and flower bud differentiation was ineffective than natural light. Fruit thinning enhanced fruit quality as well as flower bud differentiation through an increase of leaf number per fruit, over 40 in Citrus junos.

• Journal of Bio-Environment Control
• /
• v.15 no.3
• /
• pp.283-288
• /
• 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 Plant Biology
• /
• v.27 no.3
• /
• pp.129-138
• /
• 1984

Floral structures of 11 korean lauraceous species belonging to six genera have been studied. Machilus is a primitive genus having relatively large bisexual flower, six tepals and staminodes in fourth whorl of stamen. The flowers of Neolitsea are highly reduced state as unisexual flower, six stamens arranged to three whorls and no staminode in the flower, so regared as more advanced group. Intrafamilial classification systems of Nakai (1939) and Pax (1891) are more reasonable but still have some discrepancies with results. The origin of tepals of this group has been a long controversial problem; whether the differentiation of tepals occur. Teratological study of Lindera erythrocarpa, inner tepals of this group must be originated from the staminode and outer tepals from leafy tepals. Although morphological differentiation does not sitll occur, inner and outer whorls of tepals are originated through different way.

• Journal of Korean Society of Forest Science
• /
• v.57 no.1
• /
• pp.45-51
• /
• 1982

The environmental influence on cone crop of Pinus koraiensis has been studied by means of correlation and regression analysis of number of 1-year-old cone and meteorological data. A positive effect on cone crop is brought about by low air temperature during the year of flower bud differentiation and much sunshine duration for the year and the winter before flower bud differentiation. The weather of June before flower bud differentiation is very important for cone production.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.540-544
• /
• 2001

The effect of long day treatment on the growth and flower bud differentiation of persimmon tree grown in a heated plastic house was investigated. The rate of leaf sprout was 65% in the long day treatment and 71% in natural day (control). In the long day, the shoot grew 16.7 cm longer, full bloom and harvest days were shorter, fruit weight was 16% lighter, and the sweetness and firmness of fruit were lower. The photosynthesis rate in the long day treatment was higher, showing the tendency of increasing with time. However, the rate of photosynthesis increased after 1600 hours showed higher than the control. Carbohydrate accumulation in the shoot was decreased, with higher nitrogen content and lower C/N ratio in the long day. The number of flower primordia per bud was less, and the days for differentiation was longer in the long day.

• Proceedings of the Zoological Society Korea Conference
• /
• 1995.10b
• /
• pp.312.2-312
• /
• 1995

No Abstract, See Full Text