• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.243-250
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• 2004

In an effort to optimize tissue culture responses of Italian ryegrass(Lolium multiflorum Lam.) for future genetic manipulations to improve forage characteristics, the effects of culture medium supplements on tissue culture responses were investigated with mature seeds of three cultivars, 'Jeanne', 'Florida-80' and 'Metro', as explant tissues. For all explants, MS medium containing 5mg/L 2,4-D was optimal for embryogenic callus induction from mature seed and had a strong effect on successive plant regeneration. The optimal concentration of dicamba for the induction of embryogenic callus from mature seeds was 7mg/L. The highest plant regeneration frequency was observed when embryogenic callus was transferred to N6 medium supplemented with 1mg/L 2,4-D and 5mg/L BA. Plant regeneration frequency of callus cultured in the dark was higher than that of cultured in the light. Casein hydrolysate and L-proline improved both in embryogenic callus induction from mature seeds and plant regeneration. High-frequency regeneration system established in this study will be useful for molecular breeding of Italian ryegrass through genetic transformation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.4
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• pp.193-198
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• 2006

Effects of acetosyringone and on Agrobacterium-mediated transformation of orchardgrass were investigated. Embryogenic calli induced from 3 varieties, Frontier, Potomac and Roughrider, were infected and co-cultured with Agrobacterium EHA101 carrying standard binary vector pIG121Hm encoding the hygromycin phosphotransferase(HPT), neomycin phosphotransferase II(NPTII) and intron-containing ${\beta}-glucuronidase$ (intron-GUS) genes in the T-DNA region. The effects of varieties and acetosyringone(AS) concentrations on transformation and the expression of the GUS gene were investigated. Inclusion of $200{\mu}M$ AS in inoculation and co-cultivation media lead to a significant increase in stable transformation efficiency. Hygromycin resistant calli were developed into complete plants via somatic embryogenesis. GUS histochemical assay and PCR analysis of transgenic plants demonstrated that transgenes were integrated into the genome of orchardgrass.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.3
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• pp.177-183
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• 1993

This study was conducted to obtain the transformed tobacco plants with S. cerevisiae Acid phosphatase gene(PH05) using Agrobacterium tumefaciens and th confirm plant transformation and gene expression. the results obtained were summarized as follows: APase activity of Saccharomyces cereviase NA 87-11A was remarkably showed up as deep red color when assayed by Tohe and Oshima(1974). PH05 fragment, Apase gene, was obtained from pVC727G and the graphically estimated size was about 1.5kb by agarose gel electrophoresis. The sequencing results of 5'end and 3'end of PH05 using dideoxy chain termination method were coinsided with the full length nucleotide already. pBKJ I vector was constructed by isolation of PH05 fragment from pVC727-1 and pBKSI-1 digesred with Sma I and Xba I. Isolated plasmid from transformed A. tumefaciens with constructed pBKJ I when it was electrophoresed with agarose gel. The dosc of tobacco leaf was cocultivated 재소 transformed Agronacterium tumefaciens. Transformed shoots were selected on kanamtcin-containing MS-n/B medium and they were regenerated. The transgenic tobacco plants were elucidated by isolation of genomic DNA and genomic southern hybridization using ${\alpha}-^{32}P$ labelled PH05 fragments. The PH05 in transformed tobacco plants was expressed in leaf, stem and root, and its APase activity was estimated as deep red color by Tohe method.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.21-24
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• 2004

To determine lethal temperature of alfalfa (Medicago sativa L. cv Vernal) at heat-stressed conditions, seedlings grown in a small pots for 4 weeks were subjected to different temperature regimes of heat treatment. No apparent demage was observed when the plants were treated at 45, 50 or $60^{\circ}C$ for 1 h. Heat treatments at 60 and $65^{\circ}C$ for 1 h, several plants were withered and showed damage symptom on their leaves. When the plants were exposed to $70^{\circ}C$ for 1 h, most of leaves were severely withered, but it was not lethal conditions for the whole plants. By contrast, most of plants were died within one day after heat treatment at $80^{\circ}C$ for 1h. Furthermore, plants exposed to $80^{\circ}C$ for 50 min were also died within 7 days. It was found that new shoots were regenerated from the plants that had been treated at $80^{\circ}C$ within 45 min. These results indicate that heat treatment at $80^{\circ}C$ for 50 min is an optimum condition to distinguish the lethality of alfalfa plants. Simple viability assay system established in this study will be useful fer selection and characterization of heat-tolerant transgenic alfalfa plants.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.25-28
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• 2004

To determine lethal temperature of orchardgrass (Dactylis glomerata L. cv. Janbeol 102) developed in Korea at heat-stressed conditions, seedlings grown in a amall pots for 4 weeks were treated at $45^{\circ}C$, $50^{\circ}C$ or $55^{\circ}C$ for 1 h. Heat treatments at $60^{\circ}C$ and $65^{\circ}C$ for 1 h, several plants were withered and showed damage symptom on their leaves. When the plants were exposed to $70^{\circ}C$ for 1 h, most of leaves were severely withered, but it was not lethal conditions for the whole plants. By contrast, most of plants were died within one day after heat treatment at $80^{\circ}C$ for 1h. Furthermore, plants exposed to $80^{\circ}C$ for 55 min were also died within 7 days. It was found that new shoots were regenerated from the plants that had been treated at $80^{\circ}C$ within 50 min. These results indicate that heat treatment at $80^{\circ}C$ for 55 min is an optimum condition to distinguish the lethality of orchardgrass plants. Simple viability assay system established in this study will be useful for selection and characterization of heat-tolerant transgenic orchardgrass plants.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.217-222
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• 2011

Success in molecular breeding for better adapted varieties to environmental stresses depend upon the concerted efforts by various research including tissue culture, transformation, genetics and breeding. In order to optimize tissue culture conditions of Siberian wildrye grass, the effects of plant growth regulators on callus induction and plant regeneration were investigated with mature seeds. The highest callus induction frequency was observed when the mature seeds were cultured on MS medium supplemented with 5 mg/L 2,4-D. The highest plant regeneration frequency was observed when callus was transferred to N6 medium supplemented with 1 mg/L 2,4-D and 3 mg/L BA. Regenerated plants were grown normally when shoots were transplanted to the soil. A short tissue culture period and regeneration system would be beneficial for molecular breeding of Siberian wildrye grass by the production of transgenic plant.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1098-1113
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• 2021

Maturation process of alfalfa (Medicago sativa L.) could be prevented by the reduction of lignin content in terms of conventional breeding or transgenic technology. Alfalfa could exhibit higher leaf/stem ratio, with a concern of yield loss. The objective of this study was to compare forage yield and nutritive value of low lignin alfalfa and two reference varieties subjecting to two harvest intervals and three seeding rates. The experimental design was a randomized complete block in a split-split plot arrangement with four replicates, where harvest intervals (28-day and 35-day) were assigned to whole plots, seeding rates were subplots, and varieties were sub-subplots. The weighted mean nutritive value was applied to two production years of 2016 and 2017. Hi-Gest 360 (low lignin alfalfa) provided similar yield potential and increased nutritive value compared to two reference varieties. Over a two-year production period, alfalfa harvested at every 28-day interval provided more economic returns than those at 35-day interval. For the seeding year and first production year, five cuts made by the 28-day interval produced more yield than four cuts by the 35-day interval. Due to limited rainfall in May 2017, a sharp drop of the first cutting overturned the advantage of the five-cut system. Shorter intervals between harvests generally increased crude protein (CP) concentrations. The differences of relative feed value (RFV) between two harvest intervals tended to be great during the first and second cuttings. Overall, harvest interval had a large effect on nutritive value and a more significant effect on alfalfa dry matter yield than variety selection. Seeding rate did not affect alfalfa yield and nutritive value.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.341-346
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• 2004

To determine lethal temperature of birdsfoot trefoil(BFT) and italian ryegrass(IRG) at heat-stressed conditions, seedlings grown in a small pots fur 4 weeks were subjected to different temperature regimes of heat treatment. No apparent damage was observed BFT and IRG were treated at 45, 50 or $60^{\circ}C$ for 1 h. And also heat treatments at 60, 65 and $70^{\circ}C$ for 1 h, both of them were withered and showed damage symptom on their leaves but it was not lethal conditions for the whole plants. By contrast, most of plants were prominently withered within one day after heat treatment at $80^{\circ}C/60min$. When BFT was exposed to $80^{\circ}C/60$ min, they were died within 6 days but there was found that new shoots were regenerated from the plants that had been treated at $80^{\circ}C$ within 55 min. IRC was also died within 2 days that exposed to $80^{\circ}C/20$ min but there was found that new shoots were regenerated from the plants that had been treated at $80^{\circ}C$ within 15 min. These results indicate that heat killing temperatures of BFT and IRG plants are $80^{\circ}C/60$ min an $80^{\circ}C/20$ min respectively. Simple viability assay system established in this study will be useful for selection and characterization of heat-tolerant transgenic BFT and IRG plants.