• Journal of Plant Biology
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• v.37 no.2
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• pp.159-166
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• 1994

Direct current (DC) applied to cotyledons during a 16 h inductive dark period inhibited the flowering in the short-day plant, Pharbitis nil Choisy cv. Violet. The inhibitory effect of DC was more profound when the current flowed from roots to cotyledons, showing its polarity-dependent action. The second half on the inductive dark period was more sensitive to DC stimulus. The flowering was significantly depressed only when DC stimuli were applied to the translocation path of the floral stimulus from the induced cotyledon to the apex, suggesting that the transport of floral stimulus was damaged by the DC treatment. The vegetative apex culture bioassay system showed that a significant level of the floral stimulus activity existed in the phloem exudate from the cotyledons which would fail to form their own floral buds. These results strongly support the hypothesis that DC partially impede, at least temporarily, the transmission path of the floral stimulus from florally-induced cotyledon to the apex, rather than depressing in situ synthesis of the floral stimulus.

• Journal of Photoscience
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• v.12 no.3
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• pp.163-169
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• 2005

Recent reports suggest that floral organs such as sepals, petals, stamens, and carpels are specified by quaternary MADS protein complexes with different combinations. The formation of quaternary complexes of ABCDE MADS proteins may be the molecular basis of ABCDE model for the floral organ development. The MADS complexes involved in each floral organ development seem to be conserved in at least dicot species although detailed molecular mechanism is slightly different depending on species. Even in monocot, at least rice, MADS complexes similar to those in dicot exist, suggesting that the floral organ specification by MADS protein complexes may be conserved in most of plants. The MADS protein complexes may have more specific recognition of target genes or more transcription activation ability than monomers or dimers, resulting in finely regulated floral organ development.

• The Korean Journal of Ecology
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• v.14 no.4
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• pp.415-433
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• 1991

Seasonal variation in size and number of floral structures was examined in two massachusetts populations of chelidonium major, a self-compatible herb. All floral charcters except for anther number per flower declind significantly during a 3 week period. However, temporal patterns were not identical among characters or between popolations. The result indicate that floral characters varied in conjunction with flower diameter,but that the pattern of changes in floral characters in response to environments may not be easy to predict. Principal components analysis was conducted to environments may not be easy to predict. principal compenents analysis was conducted tl identify the functional relationship among floral male function, and female function, respectively, perhaps reflecting the functional distinction of floral characters. Based on this pattern, the relative allocation to sexual structures within flowers was examined: male allocation was relatively greater than female allocation eary or in the middle of flowering season, depending upon populations. Temporalvariation in relative allocation within flowers was not independent of seed tield components:; different combinations of the size and number of floral characters were correlated with different seed yield components, for example, either seed size or number per fruit, during a season. in particular, allocations to attractive and male structures were highly correlated with mean seed weight only earlier in the season. These result provide some evidence that flowering phenolgy is an important comportant to be considered in the study of sexual allocation.

• Journal of Plant Biology
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• v.32 no.2
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• pp.101-107
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• 1989

Luffa acutanqula var. amara exhibits floral and extrafloral nectaries. The floral nectaries are restricted to the torus of the male flowers, while the extrafloral nectaries are observed on foliage leaves, probract, outer surface of calyx and pedicels. The floral nectaries develop from a group of epidermal and sub-epidermal initials which differentiate into secretory and subsecretory zones respectively during further divisions. The extrafloral nectary initiates from a single papillate nectary initial which gives rise to mature nectary comprising stalk layer, secretory and subsecretory tissues. Both the floral and extrafloral nectaries are vascularized. Interactions between insect-visitors and the plant with special reference to their functions are also discussed.

• Korean Journal of Plant Taxonomy
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• v.48 no.3
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• pp.185-194
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• 2018

A comparative floral morphological study of 19 taxa in Persicaria sect. Cephalophilon with four taxa related to Koenigia was conducted to evaluate the taxonomic implications. The flowers of P. sect. Cephalophilon have (four-)five-lobed tepals; five, six, or eight stamens, and one pistil with two or three styles. The size range of each floral characteristic varies according to the taxa; generally P. humilis, P. glacialis var. glacialis and Koenigia taxa have rather small floral sizes. The connate degrees of the tepal lobes and styles also vary. The tepal epidermis consists of elongated rectangular cells with variation of the anticlinal cell walls (ACWs). Two types of glandular trichomes are found. The peltate glandular trichome (PT) was observed in nearly all of the studied taxa. The PT was consistently distributed on the outer tepal of P. sect. Cephalophilon, while Koenigia taxa and P. glacialis var. glacialis had this type of trichome on both sides of the tepal. P. criopolitana had only long-stalked pilate-glandular trichomes (LT) on the outer tepal. The nectary is distributed on the basal part of the inner tepal, with three possible shapes: dome-like, elongated, and disc-like nectary. The nectaries are always accompanied by elongated or spheroidal papillae. Various combinations of floral characters (e.g., the numbers of stamens and styles, the stigma shape, the nectary shape, ACWs, cuticular striation and the trichome type and distribution) of P. sect. Cephalophilon are useful when attempting to recognize the infrasectional levels of P. sect. Cephalophilon recently proposed. Here, we describe the floral characteristics in detail and discuss the taxonomic significance of the floral characters.

• Genomics & Informatics
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• v.20 no.4
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• pp.40.1-40.8
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• 2022

The concepts of phylogeny and floral genetics play a crucial role in understanding the origin and diversification of flowers in angiosperms. Angiosperms evolved a great diversity of ways to display their flowers for reproductive success with variations in floral color, size, shape, scent, arrangements, and flowering time. The various innovations in floral forms and the aggregation of flowers into different kinds of inflorescences have driven new ecological adaptations, speciation, and angiosperm diversification. Evolutionary developmental biology seeks to uncover the developmental and genetic basis underlying morphological diversification. Advances in the developmental genetics of floral display have provided a foundation for insights into the genetic basis of floral and inflorescence evolution. A number of regulatory genes controlling floral and inflorescence development have been identified in model plants such as Arabidopsis thaliana and Antirrhinum majus using forward genetics, and conserved functions of many of these genes across diverse non-model species have been revealed by reverse genetics. Transcription factors are vital elements in systems that play crucial roles in linked gene expression in the evolution and development of flowers. Therefore, we review the sex-linked genes, mostly transcription factors, associated with the complex and dynamic event of floral development and briefly discuss the sex-linked genes that have been characterized through next-generation sequencing.

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.51.2-51
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• 1999

No Abstract, See Full Text

• Journal of Plant Biology
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• v.38 no.3
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• pp.227-234
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• 1995

Exogenous putrescine of 0.5 mM or higher concentratons applied during a 16 h inductive dark period could elevate putrescine content in cotyledons of Pharbitis nil Choisy cv. Violet, a short-day plant, resulting in complete blocking of photoperiodic floral induction. Titers of putrescine, spermidine and spermine in the cotyledons were traced throughout a 16 h dark period. While non-induced cotyledons under continous light slightly increased levels of polyamines, induced tissue maintaiend its putrescine, spermidine and spermine levels as low as 66.4%, 60.9% and 84.9% of non-induced levels respecitvely. Endogenous polyamines kept at lower levels in the inductive dark period were found to upsurge by a night break treatment of 10 min light in the middle of the dark and consequently the inductive dark effect was canceled. Elevation of polyamine titers could also be induced by 100 $\mu$L/L ethylene treatment which completely suppressed floral induction. Compared to untreated cotyledons, ehtylene-treated tissues increased putrescine content by as much as 136.5% in 12 h and spermidine level by up to 130.1% in 8 h. Ethylene-treated cotyledons not only increased endogenous polyamine content but also liberate ethylene in the second half of the inductive dark period accumulating up to three to fourfold level supporting a hypothesis that ethylene-treated tissues are stimulated to produce ethylene which in turn accelerates polyamine biosynthesis in the tissues. It is postulated that substantially low polyamine titers in the inductive dark period would be one of the necessary factors controlling photoperiodic induction of flowering in Pharbitis nil and the inhibitory effects of night break and exogenous ethylene treatment may be atributed to their action to stimulate endogenous polyamine production.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.10a
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• pp.57-61
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• 2004

• Journal of Forest and Environmental Science
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• v.26 no.2
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• pp.95-102
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• 2010

Jatropha curcas is an oil bearing species with multiple uses and considerable economic potential as a biofuel plant. Plant flowering and breeding characteristics are important for us to understand the reproduction of plant populations. The present study describes the floral biology and flowering phenology of J. curcas which is a prerequisite for hybridization program for genetic improvement through conventional breeding. The plant produces flowers in dichasial inflorescences. Normally, the flowers are unisexual, and male and female flowers are produced in the same inflorescence. Only a few male flowers are produced in an inflorescence, and fruits are produced only through pollination between different flowers from the same or different plants. This study includes a description of the inflorescence, flower anatomy of both male and female flowers, female : male ratio, pollen : ovule ratio, flowering phenology, pollen viability, stigma receptivity, comparison of selfing methods and a comparison of geitonogamy and xenogamy. This information may be useful in J. curcas breeding programmes.