• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.184-189
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• 2011

To optimize tissue culture conditions for genetic transformation of Zoysia matrella (L.) Merr., we investigated the effects of different plant growth regulators and medium supplements on plant regeneration using stolon explants excised from mature plant grown in a green house. Plant regeneration frequency was 33.3% when stolon tissues with a node were cultured on the regeneration medium supplemented with 0.5 mg/L 2,4-D and 1 mg/L of kinetin. Comparing the basal media tested, MS medium showed higher plant regeneration performance than N6 or SH medium. Addition of 5 mg/L $AgNO_3$ with 10 mg/L cysteine improved frequency of plant regeneration up to 40%. Among different carbon sources, 3% sucrose was found to show the best for regeneration frequency. This rapid and efficient plant regeneration system would be useful for using genetic transformation experiments of manilagrass without intervening callus-mediated regeneration.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.2
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• pp.100-104
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• 2013

Zoysiagrass (Zoysia japonica Steud.) is an important forage and turfgrass that spreads by stolons and rhizomes. Zoysiagrass stolon can be used directly for Agrobacterium-mediated genetic transformation by exploiting the potential of direct shoot formation. However, surface sterilization of field-grown stolons is difficult and remains to be explored. We developed an effective surface sterilization and culture method using the stolon explant for infection with Agrobacterium tumefaciens. Among various treatments, sequential disinfection in 30% bleach for 15 min followed by 0.1% mercuric chloride for 25 min resulted in the highest number of clean stolons. The efficacy of mercuric chloride was increased under vacuum conditions by incubating at 800 mbar for 5 min. The inclusion of 2.5 mg/l amphotericin B further prevents fungal growth in in vitro cultures. This protocol would speed up the development of transgenic plants by utilizing field-grown stolon nodes.

• Asian Journal of Turfgrass Science
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• v.2 no.1
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• pp.49-58
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• 1988

질소비료 3수준(0,350,700kg N-ha-1year-1) 및 예초간격 3수준( 10,20,30일 간격)하에서 이 요인들이 식물체 각부위(엽, 엽초를 포함한 차, 포복경 및 근)내, N,P,k,Ca,Mg 및 가용성 탄수화물함량에 여하히 영행을 미치는가게 대해서 1983년 6월부터 10일 까지 대전 배재대학실험포장에서 조성한지 3년 지난 한국잔디를 대상으로 실험하였던 바 결과는 다음과 같다. 1. 질소 증시한 결과 식물체 각부위내 N함량은 증가하였다. 특히 N성분은 엽부위에 다량으로 집적 되어 있어 저장양분으로서의 역할을 하지못하는 것으로 사료되었다. 2. 질소비료에 대한 P성분의 반응은 식물체부위에 따라 변화가 심하게 나타났는데 엽부위로서는 P함량이 감소한 반면, 경 및 포복경에서는 예초간격이 30일에서 10일로 단축되었을 때 한하여 증가하는 양상 을 보였다. 3. K 함량은 질소를 증랭시용할때 엽과 경부위에 특히 많이 축적되었으며 근부위에서는 질소시용이 오히려 K함량을 감소시키는 요인으로 작용하였다. 그러나 N과 K함량간에는 지상부위와 포복경에서 정의 상관관계가 인정되었다. 4. Ca 함량은 엽과 경부위에서 예초간격을 짧게 하였을때 질소시용에 따른 부의 반응을 보였다.5. Mg 함량은 질소나 예초간격에 거의 영향을 받지 않았다. 6. 가용성 탄수화물함량은 질소시용량이 증가함에 따라 비례적으로 감소하였다. 그러나 예초간격의 영향은 경부위를 제외한 각부위에서 나타나지 않았다. 7. 영양성분에 대한 예초간격의 효과는 질소만큼 크지 않았으나 질소시용과 함께 나타난 유의적 변화는 부위별로 각각 다르게 표현되었다. 즉 N함량은 예초간격을 단축하였을 때 엽 및 경부위에서만 증가되었고 Ca 함량은 30일간격으로 연장할때만 증가되는 경향이었다. 한편 K 및 Mg함량은 예초간격에 의해 영향을 받지 않거나 변동이 심한 상황으로 나타났다.

• Asian Journal of Turfgrass Science
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• v.1 no.1
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• pp.49-55
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• 1987

Zoysia japonica를 부위별로 나누어서 그들간의 amylase와 nitrate reductase의 활성을 조사한 결과는 다음과 같다. 1. Amylase의 활성은 관부에서 8.36~9.46 unit/mg.rotein/hr.로 가장 높았고 이삭에서 2.04 unit/mg.rotein/hr.로 가장 낮았다. 포복경, 뿌리, 잎에서의 amylase의 활성을 각각 5.42~5.82, 3.76, 2.32~3.16 unit/mg.rotein/hr.나타내었다. 2. Nirate reductase의 활성은 빛을 많이 받는 잎에서 0.35~0.66 n mole/mg.rotein/hr.로 가장 높았고 관부에서 0.06~0.10 n mole/mg.rotein/hr.로 가장 낮았다. 이삭과 포복경에서는 각각 0.31,0.27~0.63 n mole/mg.rotein/hr.를 나타내었다. 이러한 결과로부터 저장기관인 관부나 관부 절간에서 높은 amylase의 활성을 이용하여, 양분을 이삭으로 이동시키고 있음을 알 수 있었다. nitrate reductase의 활성은 chloroplast를 갖지 않는 기관보다 광합성기관에서 더 높았다. 잔디밭에서 같이 사는 크로버와 비교해 보면 amylase의 활성이 Zoysia japonica보다 2배가량 더 높았다. 이러한 결과로부터 잔디밭에서 크로버가 더 생장력이 큼을 알 수 있었다.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.493-502
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• 2021

A Vegetative Propagation by Runner(VPR) Algorithm-based on MPPT Algorithm that can track MPP by adapting to external environmental changes is presented. VPR is an optimization algorithm that mimics the plant ecology of movement and reproduction based on vegetation organs. The VPR algorithm includes a procedure for aging and a procedure for searching the surroundings by rhizomes. Accordingly, it is possible to continuously search around the optimal point. Therefore, the VPR-based MPPT algorithm can continuously search for an optimal point by adapting the changes in the external environment in the process of executing the MPPT algorithm. In this paper, we analyzed the performance of the VPR-based MPPT algorithm by a number of simulations. In addition, the superiority of performance was compared by performance comparison in the same environment as MPPT algorithm based on PSO.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.265-269
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• 2021

This study was conducted to provide primary data through analysis of zoysia grass genetic resources to develop grass cultivars with beneficial novel properties. Zoysia grass (Zoysia. spp) is native to Korea, and is mainly propagated through stolons. However, since seed coat treatment technology was developed, the breeding of sexually reproductive grass variants has become possible, necessitating characterization of the floret appearance rate in the secured zoysia grass genetic resource before developing sexually reproductive cultivars. In this experiment, 549 grass lines were examined, revealing that florets appear in only 43 lines (7.81%). Survival rates after transplantation, and stolon generation rates displayed a significant positive correlation (Rho = 0.44). Survival rates after transfer, and rates of stolon production displayed very low correlations with floret appearance (Rho = -0.11 and Rho = -0.06). No significant results were obtained in 43 lines that displayed >20% floret appearance. To breed sexually reproductive grass variants, it is thus necessary to secure more genetic resources, considering the low rate of floret appearance. Finding traits that predict floret appearance at an early stage is also required.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.26-32
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• 1995

Weak persistence of white clover （Trifolium repens L.） under continuous grazing has been limited its availability in the mixture with grasses. The experiment was done to determine the effect of defoliation interval on $N_2$ fixation. nitrogen and carbohydrate partitioning of contrasting white clover cultivars. Individual plants of Osceola（large leaf）, Grasslands Huia （me-dium leaf）, and Aberystwyth S184 （small leaf） were grown in 15cm plastic pot containing a 1：2：1 soil：sand：Promix mixture for 55 days, and then clipped to remove all fully expanded leaves every 7, 14 or 28 days. To measure the cultivar response, plants were sampled immediately before final harvest （0） and on 1, 3, 7, 14, and 28 days after the final harvest, and then seperated leaves and petioles, stolons and roots for chemical analysis. Total nonstructural carbohydrate （TNC） concentrations of stolons and roots, and nitrogen con-centration of all the fractions inclined with increased defoliation interval. Those of Osceola, large leaved, were greater than the other cultivars showing different partitioning patterns between stolons and roots. Concentration of TNC was less in roots than in the other fractions while that of nitrogen declined in the order of leaves and petioles, roots and stolons. $N_2$ fixation rate of larger leaved cultivar, Osceola, was higher than that of smaller leaved cultivar. TNC and nitrogen concentrations of all the fractions and $N_2$ fixation rate were reduced as defoliation was imposed, defoliation interval declined or regrowing period become shorter. The partitioning patterns of TNC and nitrogen among the fractions were modified by defoliation interval and cultivars.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.54-63
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• 1994

Runner-derived(Expt.1) and tissue culture-derived strawbeery plantlets(Expt. 2) were grown in pots under greenhouse condition and inoculated with inocula of the vesicular-arbuscular mycorrhizal(VAM) fungi isolated from a field strawberry plants. Total biomass of mycorrhizal strawberry plants was significantly increased. There was a similar tendency in the number of cluster and flower at 20 weeks after inoculation, and VAM fungi inoculation positively influenced the leaf number, leaf length, leaf width and petiole length of strawberry plants in all investigated times. However, no difference was in the flowering time of strawberry plants. Leaf margin of non-inoculated strawberry plantlets turned into raddish brown(7.5R 4/8) from around 4 weeks after habituation. Inoculation of VAM fungi at the time of habituation was much more effective in stimulating plant growth. VA mycorrhizal dependency were 162.7 % in the runner-derived strawberry plants, Dependency with pre-and post-habituated incoulation in tissue culture-derived plants was respective 116.4% and 106.0%. The levels of mycorrhizal colonization were increased with plant growth and infection rates by endophytes at harvest time were 47.5% in Expt. 1, 56.4% in Expt. 2, respectively. Contents of phosphorus, potassium and calcium in mycorrhizal strawberry plants at harvest time were higher than non-mycorrhizal ones however, magnesium concentration was decreased. These experiments demonstrated that VAM fungi could be introduced into nursery stages of strawberry plantlets including the temporary planting period to improve growth and plant nutrients uptake by mycorrhizal plants.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.130-132
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• 2006

Objective of this study was conducted to determine the proper transplanting distance for turf cultivation in the bare land. For investigating the proper transplanting distance of turf cultivation, it were measured the growth characteristics as plant height, root length, number of branching, number of nodule and length of stolon, and yield properties such as fresh weight and dry matter. In $30{\times}30cm$ of transplanting distance plot, plant height, root length, number of branching, number of nodule and length of stolen were 14.1cm, 22.0cm, 7.0, 31 and 77.5cm, and also the fresh weight and dry matter were 16.1 and 11.0g/plant, respectively. It was observed that growth characteristics and yield properties were highest at $30{\times}30cm$ of transplanting distance, respectively. Therefore, it considered that the proper transplanting distance was $30{\times}30cm$ for turf cultivation in the bare soil.

• Korean Journal of Plant Taxonomy
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• v.34 no.4
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• pp.359-364
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• 2004

Sedum tosaense Makino (Crassulaceae), an unrecorded species in Korean flora, was collected from parasitic crater, Sangumburi in Jocheon-eup Bukjeju-gun, Jeju-do. This species is most similar to S. bulbiferum and S. orizifolium, but differs in some substantial characters. S. tosaense is perennial and stoloniferous herb with bulbils on stems, while S. bulbiferum is annual or biennial herb without bulbils in leaf axil. In addition, S. tosaense has leaves emarginate at apex whereas S. bulbiferum has leaves somewhat uneven at apex. the leaves of S. tosaense are conspicuously flattened and spatulate in shape at the stem without flowers, but those of S. orizifolium, are terete or slightly flattened and linear to narrowly oblong in shape.