• Journal of Photoscience
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• v.7 no.3
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• pp.103-108
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• 2000

We have evaluated a new mutagenesis strategy called random insertional mutagenesis with subtracted cDNA fragments. The cDNAs from long day Arabidopsis plants were subtracted by cDNAs from short day plants using PCR based cDNA subtraction. The subtracted cDNAs were inserted between 35S promoter and 3'-NOS terminator regardless of orientation. When the cDNA library was used for the random insertion into Arabidopsis genome by Agrobacterium-mediated transformation, approximately 15% of transformants showed abnormal development in leaf, floral organ, shoot apex. When 20 mutants were analyzed, 12 mutants showed single cDNA fragment insertion and 8 mutants showed more than 2 transgene insertions. Only two mutants among 12 mutants that have single cDNA insert showed consistent phenotype at T2 generation, suggesting the genetic instability of the mutants.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.428-435
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• 2004

Alkaloid producing species of plants have long been a major component of the medicinal social and magico-religious aspects of human culture. A diverse array of biological activities has been attributed to different alkaloids including numerous members of benzylisoquinoline family of alkaloids. For biotechnological approaches of alkaloid biosynthesis in poppy family, plant regeneration protocol through somatic embryogenesis or shoot organogenesis is a first step. This paper describes the methods and applications of plant regeneration of poppy family.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.119-124
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• 2004

For long-term conservation of germ plasm, somatic embryos of sweet potato are important because shoot tips are not amenable to liquid nitrogen storage. Somatic embryos from different genotypes were used for induction of somatic embryogenesis in a large number of genotypes. Somatic embryogenesis was induced on 2,4-D medium in all the 11 genotypes, collected from geographically distinct locations. Genetic fidelity of the regenerated plants was confirmed by morphological and RAPD markers.

• Asian Journal of Turfgrass Science
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• v.12 no.4
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• pp.195-202
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• 1998

The development of a protocol for high efficiency of embryogenic callus separation, maintenance and plant regeneration from the seeds of zoysiagrass cv. Zenith was studied. Embryogenic callus ratio is absolutely determined by genotype, but by adding high concentration of copper into medium, changing light condition and maintaining callus on initial induction medium for 8∼10 weeks, embryogenic callus can be easily distinguished and its growth can be promoted. There were significant differences among selected callus lines (each from one seed) according to their growth rates and regeneration percentages. Callus pre-treatment with activated charcoal inhibited callus growth, increased the level of precocious germination during culture and promoted shoot cluster formation after transfer to regeneration medium. For long-term callus maintenance, N6AA medium was better than MS medium, because the former inhibited non-embryogenic callus formation and kept vigor of embryogenic callus. The best callus lines Z-(5) has been successfully used for transformation and somaclonal variation selection in our laboratory.

• Journal of Plant Biology
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• v.37 no.3
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• pp.343-347
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• 1994

In order to compare the adjustment of 6 oak species to water stress, the components of water status, tissue elastic modulus, free proline content of leaves and morphological characteristics were determined in pot culture. uercus dentata and . mongolica responded effectively to drought with high root : shoot (R/S) ratio or maintenance of high turgor pressure by large and fast osmotic adjustment and . variabilis with maintenance of high turgor pressure by low elastic modulus under drought. Meanwhile, . aliena and . serrata responded effectively with low omotic potential (Ψo) at full saturation and . acutissima with long root in spite of rigid cell wall and high osmotic potential (Ψo) at full saturation. Proline content in leaves of . dentata, . mongolica and . aliena increased early and rapidly at high leaf water potential (Ψleaf). The results indicate that 6 oak species have adjustment different from each other to water stress.

• Journal of Wetlands Research
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• v.10 no.3
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• pp.9-26
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• 2008

To clarify the reed (Phragmites australis) stand's effects on the sediment properties and its increasing pattern, breaths of reed stands in 1999 and 2000, and sediment properties - water, salt, organic matter, sulphur, nitrogen, carbon and hydrogen contents - along th depth at the three stands in 2007 were surveyed at Suncheon Bay. Regardless of reed stand, the more distance from the land was long, the more water and salt contents of sediment were high. Organic matter content of sediment was high and increased with the reed biomass at the upper layer but low regardless of biomass at the lower layer. Sulphur content of sediment was higher at old reed stand (0.33%) than at new stand (0.21%) or non-vegetated stand (0.23%). Carbon, nitrogen and hydrogen contents of sediment were similar at three stands in mean values. However, their contents were high at upper layer and low at lower layer in a stand. Therefore, the changing pattern of organic matter content with the depth was similar to but not coincided to the inorganic nutrients' ones. The mean breadth of reed stands increased $2.33{\pm}0.73m$ in 1999 and $3.65{\pm}1.64m$ in 2000. However, the increase of reed stands' breadth a year varied along the direction, year or stands, so that there was not a trend in increasing pattern. It was thought that this increasing pattern made the reed's patch round. The height and density of reed shoot in newly formed stand decreased with the distance from the center of stand. In the newly formed peripheral area of a reed stand, the shoot density was not related with the land (north) or sea (south) direction, however, the shoot height was higher in the sea (south) than in the land (north) direction.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.93-99
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• 1996

By treatment(dropping) of 0.1~0.4% colchicine solution on the sprouts of winter buds of hard wood cutting slips for 4~5 days, two lines of artificial autotetraploids from Yongchonppong and one line from Yeongbyonppong were bred and the important cultivative characteristics of those new lines were as follows. The greentip sprouting stage of the new bred lines in spring season is later than the parental varieties by two days, but growth speed of the new lines after sprouting was faster than that of the parental varieties reaching the same level development with the parental varieties at the fifth leaf sprouting stage to be mid varieties same as the origins. The leaf shape of the new bred lines was wide round and the petioloes were long and thick. The thickness of leaf was thicker than the parental varieties by 17-33% and single leaf weight was heavy. The leaf area weight increased by 21-31% and the content of chlorophyll was also higher by 11-33%. With all the characteristics, the new breds produced good quality of leaves. The length and number of branches were shorter and less, respectively, than the parental varieties, but the internode length was either same or longer than the parents. Looking at the characteristics, the constitution of shoots was slightly inferior to the parental varieties. The cold hardness expressed by the death top rate of Sawonppong 23 and Sawonppong 24 was same level as that of Yongchonppong, but Sawonppong 25 was stronger than Yeongbyonppong in it with a high infection rate of dwarf disease. The productivity was lower than the parental varieties, but young shoot rate to shoot and branch and the ratio of leaf to young shoot were higher than the parental varieties. The fertility of Sawonppong 23 and Sawonppong 24 was comparatively high with 62% of cross success, but that of Sawonppong 25 was low with 23.9% of cross success.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.146-150
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• 2017

This research investigated the effect of photo/dark period and relative humidity during dark period on the growth and quality of water dropwort in a closed-type plant factory system. At 30 days after planting, the shoot fresh weight of water dropwort under relative humidity of 60/90%(light/dark) treatment significantly higher than that under relative humidity of 60/60% treatment. The shoot fresh weight of water dropwort increased by extending light period under relative humidity of 60/60% treatment, but 16/8h photo/dark period showed the best shoot fresh weight, followed by 20/4h and 22/2h under relative humidity of 60/90% treatment. In the relative humidity of 60/90% treatment, the tipburn occurrence was reduced under 16/8h photo/dark period condition as 1.4%, whereas it was significantly increased under 20/4h and 22/2h of relatively long light time duration as 15.5% and 30.3%, respectively. In the relative humidity of 60/60% treatment, the tipburn occurrence was 15.5% under 16/8h photo/dark period condition and those under 20/4h and 22/2h photo/dark period condition were higher than 25%. The stem hardness of water dropwort was lowest in relative humidity of 60/90% and 16/8h photo/dark period treatment. The mineral contents of leaves were decreased by extending light period, but the contents of Ca were not different significantly among the treatments except the 60/60% and 22/2h treatment.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.27-33
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• 2020

To date, various kiwifruit cultivars have been developed and released. Asexual propagation by grafting onto seedlings rootstock have been widely utilized commercially in fruit trees including kiwifruit (Actinidia spp.). Most of commercial kiwifruit cultivars belong to A. chinensis and A. deliciosa. Recently, several cultivars were developed by interspecific hybridization with different species including A. arguta. There is a possibility for graft-incompatibility due to interspecific hybridization and therefore, we investigated graft-compatibility of newly released yellow-fleshed kiwifruit cultivars and a hybrid cultivar with various rootstocks of different species. The yellow-fleshed cultivars grafted onto same species, A. chinensis 'Kuimi', showed good shoot elongation, about 1 m in length 50 days after grafting. In contrast, the shoot elongation of the yellow-fleshed kiwifruit grafted onto different species was retarded. The shoot length of a hybrid cultivar (A. arguta × A. deliciosa) 'Skinny Green' grafted onto four different species was about 1 m in length, showing good graft compatibility with other species. Nevertheless, long term studies for graft compatibility of hybrid cultivars are still needed since graft-incompatibility between different species can occur several years later.

• Horticultural Science & Technology
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• v.17 no.5
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• pp.572-577
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• 1999

Research was initiated to evaluate plant growth regulator effects on the vertical shoot growth of Korean lawngrass and to determine desirable growth regulator and its rate. The experiments were conducted twice at different sites in 1995. All the tested growth regulators inhibited the growth, but the inhibition period was variable among the product in Experiments I and II. During the first week after treatment, there was approximately 10 to 20% growth reduction in most of the treated plots. In the amidochlor-treated plots, growth suppression was effective for 3 to 4 weeks at low to medium rates ($0.60mL{\cdot}m^{-2}$). A Type II growth regulator, trinexapac-ethyl exceeding the medium rate of $0.08mL{\cdot}m^{-2}$ consistently tended to suppress vertical shoot growth for 8 weeks, being above 35% reduction in both experiments. In the plots applied with mefluidide, growth suppression appeared with foliar discoloration 3 or 4 days earlier than the other growth regulators and continued to work till the 8 weeks after treatment. Suppression intensity on vertical shoot growth increased with time after treatment up to a certain period of time, depending on growth regulators. Generally, the higher the application rate, the greater the suppression intensity. Seasonal variation of activity and effectiveness of growth regulators was observed, resulting in lower suppression intensity in July than in June. It is expected to reduce mowing requirements by 30 to up to 60% for a certain period with a specific growth regulator. In low to medium maintenance of Korean lawngrass turf, a long-term suppression may be more effectively accomplished with trinexapac-ethyl rather than mefluidide and amidochlor in terms of vertical shoot growth inhibition. Therefore, turf managers will need to select proper growth regulator and determine optimum rate of application for turfgrass management, based on a defined period of mowing reduction.