• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.279-283
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• 2011

The immature embryos during seed development were examined to predict the suitable embryos for an efficient regeneration system. Five spring wheat genotypes and five winter wheat genotypes were tested using immature embryos as explants. Spring wheat genotypes showed much higher levels of plant regeneration than those of winter wheat genotypes. The highest frequencies of embryogenesis and regeneration were obtained when embryos at 13-14 days after anthesis (DAA) were used as explant and decreased using embryos at 21-22 DAA during seed development. Significant differences were also found for callus induction and regeneration as affected by immature embryo size. The regeneration efficiency was drastically decreased in spring and winter wheat genotypes when embryos larger than 2.0 mm of length were used. The optimum developmental stage and embryo length for regeneration efficiency were at 13-14 DAA and 1.0-1.5 mm, respectively. The selection of suitable embryos for the high frequencies of embryogenesis and regeneration leads us to efficient genetic improvement of wheat.

• Journal of Ecology and Environment
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• v.34 no.3
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• pp.295-305
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• 2011

Many studies have suggested the positive effects of grazing by large herbivorous mammals on seed dispersal, but little is known about how herbivores could affect the fate of ingested seeds. This study examined the effects of seed ingestion by sika deer (Cervus nippon) on seed fate in a temperate grassland established in an urban park long resided by high densities of sika deer. I compared species composition and seasonal traits of seed abundance and maturity in the grassland community with those in deer fecal pellets. In total, 27 herbaceous species were observed, including the predominant Zoysia japonica. Seed phenology and production differed among the three dominant species (Z. japonica, Digitaria violascens, and Hydrocotyle maritima). Pellets contained at least 26 species of herbaceous seeds, and their abundance differed among species. Of the 26 species, 15 were observed in the vegetation at the study site. The peak of seed abundance in pellets for the dominant species appeared 1 month after the peak of inflorescence production (but most of the inflorescences were immature and susceptible to digestion) and consequently corresponded to the peak of mature inflorescence. Because sika deer are likely to ingest seeds at any maturity stage in the grassland and immature seeds are less hardened, ingested immature seeds can suffer great losses. The results suggested that the survival of germable seeds with great losses of immature seeds may be a factor determining which plant species can be successfully dispersed by herbivores.

• Journal of Plant Biotechnology
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• v.40 no.1
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• pp.43-48
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• 2013

Oreorchis coreana Finet is threatened globally by over-collection from its natural habitats for horticultural purposes. Its rarity in nature makes this plant one of the most endangered species in Korea. In this study, we investigated the effects of sodium hypochlorite (NaOCl) on orchid seed viability and seed germination. An in vitro bioassay swelling test using immature seeds was compared with a standard chemical procedure using triphenyl tetrazolium chloride (TTC) to test seed viability. In general, the bioassay was more appropriate for estimating embryo viability after a prolonged pre-treatment (more than 1 h) in 1% NaOCl, a surface sterilant often used to enhance germination of seeds of terrestrial plants. Therefore, an efficient method for investigating in vitro swelling of immature seeds is urgently needed. We established a method for determining the viability and swelling of O. coreana seeds via in vitro examination of immature seeds. Treatment of immature seeds with 1% NaOCl for 10 min greatly enhanced the extent of swelling of immature zygote embryos when compared to untreated seeds. These data obtained here appear to be comparable to viability and swelling that occurs in O. coreana seeds via asymbiotic germination.

• Journal of Life Science
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• v.11 no.4
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• pp.311-315
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• 2001

To identify the effects embryo developmental stage and gelrite concentration on plant regeneration in seed culture of rice, mature and immature seeds of rice were cultured on the $N_{6}$ medium supplemented with2 mg/$\ell$ 2.4-D and different levels of gelrite(0.2~1.0%). The calli formed immature embryos were produced more plants than those from mature embryos. The maximum frequency of plant regeneration was achieved in the culture of the calli of immature embryos which was harvested at the 21$^{th}$ day after pollination. The plant regeneration on the medium with gelrite was more accelerate than that on the medium with agar. The highest frequency(55%) of plant regeneration was obtained from the calli transferred to the medium with 6g/$\ell$ gelrite.

• Journal of Plant Biotechnology
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• v.2 no.3
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• pp.123-128
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• 2000

To enhance in vitro plantlet regeneration efficiency of soybean through embryogenesis, the culture conditions such as material part and size of immature seed, 2,4-D, pH and solidifying agents for somatic embryogenesis were investigated. Somatic embryogenesis was induced from the immature embryo, immature cotyledon and embryonic axis explants of the immature seed on MS medium supplemented with 2.0 mg/L 2,4-D. The highest rate (up to 22.9%) of somatic embryogenesis was obtained from the immature cotyledon, following embryonic axis and the immature embryo. The rate varied with the developmental stages of seed. The maximum rate (25.4%) of embryogenesis was obtained from 3-4 mm length of the seed (after 25 days of flowering). The optimum concentration of 2,4-D for embryogenesis was 10 mg/L. The optimum pH was at 5.8 and solidifying agent for medium was better with 0.4% gelrite than with agar. For rapid multiplication of shoot tips from the germinating somatic embryos, they were cultured on MS medium containing 2 mg/L indole-3-butyyic acid (IBA) and 1 mg/L 6-benzyladenine (BA). After then somatic embryos with one and three cotyledons were transferred to the growth regulator free medium. The medium exhibited the higher rate (ca. 50%) of development than the multiplication medium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.152-155
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• 2003

Burcucumber (Sicyos angulatus L.), used as a medicinal or rootstock for cucurbitaceous crops have shown high variation in seed maturity and size. This study was carried out to determine the effect of seed maturity and size on seed germination, seedling emergence and growth of burcucumber, Seeds collected from a native site were divided into small, medium and large ones after sorted to mature and immature ones. Their germination, seedling emergence and growth were done in indoor and a green house. Mature seeds showed higher germination and seedling emergence rate than immature ones. Regardless of their maturity, medium. and small seeds showed higher germination rate than large ones. Medium and large seeds, however, had the greatest and the least seedling emergence, respectively. Seedling height, number of true leaves areas of cotyledons and true leaves except hypocotyl length were increased with increased seed size although were not affected by the maturity. Cotyledon, leaf, hypocotyl, root and their total dry weights were greater in large mature seeds than large immature ones while increased with increased seed size in both maturities.

• Journal of Ginseng Research
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• v.30 no.2
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• pp.78-81
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• 2006

Freshly harvested, immature (green) seeds of North American ginseng (Panax quinquefolius L.) were stratified for up to 3 years in plastic pails in controlled environment rooms at $5{\pm}1^{\circ}C$ for 9 months and then $21{\pm}2^{\circ}C$ for 3 months (Trt. 1, regular stratification), or continuously at $-2{\pm}0.2^{\circ}C$ (Trt. 2), or continuously at $3{\pm}0.2^{\circ}C$ (Trt. 3). During stratification at -2 and $3^{\circ}C$ embryos did not grow. On seeding in the field embryos grew rapidly and resultant seedlings were comparable to those from regularly stratified seed. Seedling emergence rate was acceptable at the industry expected rate of 68% after one year of storage, but not after two years storage when it declined to 17.5%. Seed rot was so severe in year 3 that no planting was carried out. Seedling and second year growth were similar at the three stratification temperatures; most importantly, root dry weight (economic yield) was similar. Low-temperature storage of freshly-harvested North American ginseng seed is an acceptable method for short-term retention of propagating material.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.139-148
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• 2010

Jatropha curcas L. (Physic nut) is a commercially important non-edible oil seed crop known for its use as an alternate source of biodiesel. In order to investigate the morphogenic potential of immature embryo, explants from four developmental stages were cultured on medium supplemented with combinations of auxins and cytokinins. It was found that the size of embryo is critical for the establishment of callus. Immature embryos (1.1-1.5 cm) obtained from the fruits 6 weeks after pollination showed a good response of morphogenic callus induction (85.7%) and subsequent plant regeneration (70%) with the maximum number of plantlets (4.7/explant) on Murashige and Skoog's (MS) medium supplemented with IBA (0.5 $mg\;l^{-1}$) and BA (1.0 $mg\;l^{-1}$). The above medium when supplemented with growth adjuvants such as 100 $mg\;l^{-1}$ casein hydrolysate + 200 $mg\;l^{-1}$ L-glutamine + 8.0 $mg\;l^{-1}$ $CuSO_4$ resulted in an even higher frequency of callus induction (100%). Plant regeneration (90%) with the maximum number of plantlets (10/explant) was achieved on MS medium supplemented with 500 $mg\;l^{-1}$ polyvinyl pyrrolidone + 30 $mg\;l^{-1}$ citric acid + 1 $mg\;l^{-1}$ BA + 0.5 $mg\;l^{-1}$ Kn + 0.25 $mg\;l^{-1}$ IBA. It was observed that plantlet regeneration could occur either through organogenesis of morphogenic callus or via multiplication of pre-existing meristem in immature embryos. The age of immature embryos and addition of a combination of growth adjuvants to the culture medium appear to be critical for obtaining high regeneration rates. Well-developed shoots rooted on half-halfstrength MS medium supplemented with 0.5 $mg\;l^{-1}$ IBA and 342 $mg\;l^{-1}$ trehalose. The rooted plants after acclimatization were successfully transferred to the field in different agro-climatic zones in India. This protocol has been successfully evaluated on five elite lines of J. curcas.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.175-190
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• 1987

Germination characters of the lettuce seed that received photoperiodic pretreatments of low or high temperature from the flowering to harvest. MSU-15 seed, one of the lettuce cultivars used, having high dark germination, was modified to low dark germination by the long-day treatments during the seed formation. Light-requiring MSU-16 seed was modified to the dark-germination seed by high temperature given at the seed formation period. Above results suggest that the environmental conditions given to an immature seed adhered to a mother plant bring about some modification to its native germination habit. I confirmed that the spectral quality of light could influence the phytochrome system which controlled germination characters of the progeny of lettuce seed ; plants grown in light rich in far-red energies produced light-requiring seed, but those grown in high deficient in far-red energies produced dark germination seed.

• Korean Journal Plant Pathology
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• v.10 no.3
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• pp.222-227
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• 1994

Effects of field applications of benomyl on Phomopsis seed decay of early soybeans were investigated at Suwon in 1992 and 1993. Pod and immature seed infections were markedly suppressed by benomyl application at the R6 stage whereas the spray at the R7 stage was not as effective as the spray at R6. When compared with unsprayed plots, benomyl spray at R6 resulted in decrease in Phomopsis seed infection by 37.1% and 73.9%, and increased in frequency of seed germination by 1.8% and 8.0% in 1992 and 1993, respectively. The results indicated that only one spray at early R6 could effectively reduce seed infection by Phomopsis spp.and could be adopted in a disease management program for commercial production of healthy soybean seeds.