• Journal of Plant Biology
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• v.39 no.4
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• pp.257-263
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• 1996

Flower-inducing activity in the phloem exudata of Pharbitis cotyledons was investigated using the bioassay of Pharbitis and Lemna. By SDS-PAGE and 2-D gel electrophoresis of the phloem exudate, two polypeptides of 11 kDa and of approximately 32 kDa (pI 6.9) showing qualitative changes during the flower induction were detected. A polypeptide of approximately 20 kDa (pI 4.8) specifically labeled in vivo with [35S]methionine was found during the inductive dark period in Pharbitis cotyledon tissues. The polypeptide of the equivalent molecular mass and with the identicl pI value was also detected by in vitro translation assay. Thus, it is assumed that the 20 kDa polypeptide plays a role in the process of flower induction in Pharbitis cotyledons.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.532-538
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• 1996

GA4/7 spray, injection and several cultural treatments were applied to the greenhouse-grown potted hybrid larch(Larix decidua${\times}$leptolepis) grafts and field-grown European larch seedlings to induce early flowering. A treatment consisting of repeat-ed GA4/7 sprays, alone, was the most effective flower induction treatment for greenhouse-grown, potted larch grafts. Root pruning as a adjunct treatment did not show synergistic effects. Injection for potted grafts with GA4/7 was not useful approach in this study and it resulted in increased mortality. In the field experiment with 10-Year-old larch seedlings, repeated GA4/7 sprays in combination with root pruning or with plastic mulching appears to be useful and practical means for inducing larch flowers:

• Horticultural Science & Technology
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• v.16 no.1
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• pp.15-17
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• 1998

In order to provide cool night to strawberry plant with cool air and water, an abandoned cool mine was utilized. It's effects on flower induction and fruit yield in 4 different cultivars were examined. After 70 days of transplanting, flowering frequency was below 65% and 100% in control and treatment of night cooling, respectively and regardless of cultivars. Number of flower buds and flower clusters were higher in treated plants compared with the control. Average time until flowering was much less in treated plants. In terms of yield weight and total yield, 'Suhong' was found to be the best cultivar, averaging 24.2g fruit. Cooling contributed to the 6-7 times of increase in total yield within the frame of harvesting times. The fruit were harvested at 80-97 days after transplanting.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.213-237
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• 1987

In vitro flowering system may minimize the confounded influence of non-floral meristem parts of plants in studying the relationship of a given treatment and flowering responses. We have induced flower buds from plantlets regenerated from zygotic embryo-derived somatic embryos of ginseng, which circumvented the normal 2-year juvenile period before flowering. The result suggests that the adulthood of ginseng root explants in the experiment previously conducted by Chang and Hsing (1980; Nature 284: 341-342) is not prerequired to flowering of plantlets regenerated through somatic embryogenesis. We have also induced flower buds from elongated axillary brandches from cotyledonary nodes by culturing ginseng zygotic embryos, seedlings, and excised cotyledonary nodes. It was found that 6-benzyladenine (BA) supplemented to the medium was essential for flowering, whereas abscisic acid (ABA) was inhibitory. Gibberellic acid(GA3) was also required for flowering when ABA was present with BA in the medium. The results suggest that cytokinins, gibberellins, and inhibitors play primary, permissive, and preventive roles, respective-ly, in the induction of flowering of ginseng. Tran Thanh Van (1980; Int. Rev. Cytol., Suppl. IIA: 175-194) has developed the "thin cell layer system" in which the induction of shoots, roots, or flower buds from epidermal layer explants were controlled by culture conditions and exogenous growth regulators in the medium, Utilizing the thin cell layer system, Meeks-Wagner et al. (1989; The Plant Cell 1: 25-35) have cloned genes specifically expressed during floral evocation. However, the system is too tedious for obtaining a sufficient amount of plant materials for biochmical and molecular biological studies of flowering. We have developed a garlic callus culture system and one obvious advantaging over the thin cell layer system is that an abundant cells committed to develope into flower buds proliferate. When the above cells were compared by two-dimensional gel electrophoresis with those which have just lost the competence for developing into flower buds, a few putative proteins specific to floral evocation were detected. The garlic callus culture system can be further explored for elucidation of the molecular biological mechanism of floral evocation and morphogenesis.hogenesis.

• Journal of Plant Biotechnology
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• v.41 no.3
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• pp.134-139
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• 2014

The aim of this study was to establish the condition of regeneration for white balloon flower (Platycodon grandiflorum DC. cv. Jangback) and to manage for the raising of seedling with in vitro regenerated plants. It was examined that 0.5 mg/L of NAA and 1.0 mg/L of BA was the best composition for the callus and shoot induction (up to 600%). NAA was better than IBA for the induction of root and it took 16.9 days for the induction of rooting on the MS soild media containing 0.5 mg/L of NAA and the final rooting ratio was up to 75%. Out of 5 different bed soils purchased from local market, "Tosil" was identified to be the best for the acclimation and growth of in vitro regenerated balloon flower. In detail, on 8 weeks after planting of in vitro regenerated plants in pots containing "Tosil" bed soils, the plant hight was increased up to 2-fold (12.8 cm), 3.5-fold (27) for the number of leaf and 1.5-fold (4.5 cm) for the leaf length when compared to the other four bed soils, respectively. Our preliminary results indicate that it is possible to prevent the occurrence of blue balloon flower in the massive cultivated area of white balloon flower by providing the seedlings raised from in vitro regenerated plants.

• Journal of Plant Biology
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• v.33 no.3
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• pp.183-188
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• 1990

Induction and culture of hairy roots by Agrobacterium rhizogenes A4 were carried out in Platycodon grandiflorum DC. After 2-4 weeks of inoculation with Agrobacterium rhizogenes hairy roots were formed at root segments in the balloon flower. Optimized growth of hairy roots was obtained in hormone-free MS medium, 6% sucrose and pH 5.8. The pattern of ginsenoside in the transformed roots was not different with that in the ordinary roots.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.356-363
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• 2015

This study examined the effects of different day/night temperature regimes or silver ion on growth and flowering of passion fruit 'Tai-nung No.1'. Low temperature treatment ($20/15^{\circ}C$) caused passion fruit cultivar 'Tai-nung No.1' to fail to flower. Flowering induction occurred within a temperature range of $20-30^{\circ}C$, with no significant difference in the days to first flower bud and the total number of flower buds between plants grown at $30/25^{\circ}C$ and $25/20^{\circ}C$. However, plants grown at $30/25^{\circ}C$ exhibited their first flower buds set on the higher nodes and had higher abortion rates of flower buds than those at $25/20^{\circ}C$. Plants grown at $30/25^{\circ}C$ had the most rapid growth and the shortest plastochron. We also evaluated the effect of the ethylene response inhibitors silver nitrate ($AgNO_3$) and silver thiosulfate (STS) on growth and flowering of potted passion fruit 'Tai-nung No.1', when they were exposed to low temperature conditions ($20/15^{\circ}C$) following chemical treatments ($AgNO_3$ or STS, at 0.5 or 1.0 mM). $AgNO_3$ and STS treatments induced flower formation and initial flower bud formation within approximately two weeks at $20/15^{\circ}C$ whereas non-treated control plants exhibited no flower formation. ACC content and activity of ACC oxidase in the leaves of passion fruit 'Tai-nung No.1'exposed to low temperature conditions ($20/15^{\circ}C$) were significantly inhibited by the ethylene inhibitor treatments. These results indicate that ethylene, which is produced under low temperature conditions, plays an important role in inhibiting flower formation in passion fruit.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.263-266
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• 1998

Flowergenic callus was induced from the ovary surface of Allium fistulosum L. cultured on MS medium containing 0.5mg/L NAA and 0.5mg/L BA or 0.5mg/L kinetin. After 3-4 weeks of culture, the flower buds were developed from flowergenic callus. The continuous production of flowergenic callus was proliferated, when subcultured on the medium containing 0.5mg/L NAA and 0.5mg/L kinetin. However, frequency of flower bud formation from flowergenic callus was decreased as the subculture was repeated. Histological observation reveals that the developmental pattern of flower bud from flowergenic callus was closely similar to that of natural flowers.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.27-39
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• 2005

a-Ketol linolenic acid [KODA, 9,10-ketol-octadecadienoic acid, or 9-hydroxy-10 -oxo-12(Z), 15(Z)-octadecadienoic acid] was found as a stress-induced factor in Lemna paucicostata. KODA reacts with catecholamines to generate many products that strongly induce flowering in L. paucicostata, although KODA itself was inactive. KODA contains an asymmetric carbon at the 9-position in the molecule; the 9-hydroxyl group is predominantly 9R, with an enantiomeric excess of 40% (70% 9R and 30% 9S). We analyzed two major products of the reaction between KODA and norepinephrine, named FN1 and FN2. FN1 was identified as a tricyclic a-ketol fatty acid, 9(R)-11-{(2'R,8’R,10'S,11'S)-2',8'-dihydroxy-7'-oxo-11'-[(Z)-2-pentenyl]-9'-oxa-4'-azatricyclo[6.3.1.01.5]dodec-5'en-10'-yl}-9-hydroxy-10-oxoundecanoic acid. FN2 was the C-9 epimer of FN1. FN1 was derived from 9R-type KODA and FN2 from 9S-type. FN1 showed strong flower-inducing activity, but FN2 was inactive. Pharbitis nil (violet) is a typical short-day plant; flowering can be induced by exposing a seedling cultivated under continuous light to a single 16-h dark period. We analyzed endogenous KODA levels and showed that they were closely related to flower induction: KODA sharply increased in the later part of a 16-h dark period, on the other hand, it failed to increase in the night-break experiment. In addition to it, KODA increased transiently in immature flower buds in all the plants we examined, including P. nil. No such increase of KODA was seen in foliar buds of P. nil. When KODA was sprayed on seedlings of Pharbitis, flower induction was promoted only by the (R)-form of KODA. We also found that KODA enhances flowering in garden plants such as carnations and impatienses. These phenomena indicate that KODA may be involved in flowering formationg of plants and it is potentially useful for a regulating agent for commercial plant flowering.

• Korean Journal of Medicinal Crop Science
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• v.10 no.3
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• pp.217-221
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• 2002

Callus induction and embryogenesis were studied in three different genotypes of Acanthopanax senticosus, to develop a protocol for somatic embryogenesis and acclimatization. Young leaf, stem, node, petiole, peduncle, flower and root explants were collected from 3-year old trees of A. senticosus accessions (Korea, Russia and Japan). Callus was obtained from all cultured explants but showed the higher rate of callus formation in flower cultured. For the three A. senticosus accessions, callus was well formd on MS media containing 2mg/ l of 2,4-D and 2mg/ l of TDZ, 4mg/ l of 2,4-D and 1mg/ l of TDZ than other treatments. For three A. senticosus accessions, when callus transferred to MS medium with 2,4-D, embryogenic cell formed. For A. senticosus accessions Korea, embryogenic cells were obtained on callus induced from petiole, stem, node and root explants, and induction rate was lower than 3%. 200mg of embryogenic callus was transferred to MS free liquid medium and somatic embryos of heart stage were obtained after 45days of culture. When somatic embryo of germination stage were transferred to solid medium, most of the embryos were regenerated into plantlets on 1/4 MS medium. Normal plants with both shoots and roots were transferred to greenhouse soil and were successfully acclimatized.