• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.485-489
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• 1999

The germination percentages of Quercus hybrid seeds produced in 1994 using stored pollens were low. The survival rate and height growth within 2 years differed according to crossing combinations. The survival rate and growth of seedlings from hybrid seeds produced in 1991 and 1993 were investigated. The survival rates of five-year-old and three-year-old seedlings were from 71 to 100% and from 33 to 100%, respectively. The survival rates differed according to cross combinations. The mortality of seedlings increased in proportion to the increase of percentages of dwarf seedlings. The growth of five-year-old seedlings, of which mother tree was Q. aliena, was the best. The growth of seedlings produced by artificial crossing tended to be worse than that of natural crossing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.485-495
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• 1991

This experiment was carried out to obtain the information on the crossability, variation of chromosome number in pollen mother cell (PMC) and somatic cell of the progeny from the cross between hexaploid triticale cv. Sinkihomil and two diploid rye varieties. Seed set was 39.3 to 41.6% (averaged 40.5%) in the cross between triticale (P$_1$) and rye(P$_2$), which resulted in 0.33% in F$_2$(selfed F$_1$), 2.69% in F$_1$/P$_1$ 5.47% in F$_1$/P$_2$ respectively. However, seed set was extremely low in both reciprocal crosses when triticale was used as male. Germination rate of the crossed seed was 94.0% in F$_1$ 40.8% in F$_2$(selfed F$_1$), 59.5% in F$_1$/P$_1$ and 65.9% in F$_1$/P$_2$ from the cross between triticale and rye, respectively. Pollen fertility of F$_1$ plant was averaged 18.7% in the cross between triticale and rye. Number of Uni-, Bi-, and Trivalent in PMC was 12. 6, 6.94, and 0.53, respectively, in the F$_1$ between the triticale and rye. There were 28 chromosomes in F$_1$, 21 to 34 in F$_2$, 34 to 38 in F$_1$/P$_1$ and 19 to 23 in F$_1$/P$_2$ from the cross between the triticale and rye, respectively.

• Journal of Korean Society of Forest Science
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• v.7 no.1
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• pp.19-27
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• 1968

As a preliminary investigation to obtain useful auto- and allopolyploids a ten year old tetraploid of Pinus densiflora induced from the colchicine treated seed was observed on the cytological, morphological and physioa logical characters in the present study and the results can be summarized as follows. 1. The number of chromosome at the base of needle was 48 so that it was recognized as a tetraploid. 2. The needles were thicker and the number of them on an individual was less than the 2n plant. The needle combined to a single was appeared 2%. 3. No difference was found in the number of stomata rows on the central part of needle between the tetraploid and 2n plant, however, guard cells of tetraploid increased 36% in the long diameter compared with 2n plant. 4. Microsporangiate storbile developed normally showing the same size with 2n plant while the size of pollen grain increased about 20% larger than 2n plant. 5. Germination percentage in vitro increased until 17 hours but decreased after 26 hours compared with 2n plant. The longest length of pollen tube during the germination period appeared in the tetraploid pollen.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.211-217
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• 2008

To build up data for mutation breeding of lily, sensitivity to irradiation of bulb, seed and pollen was investigated. The bulbs of seven cultivars including 'New Wave' were very sensitive to gamma rays. Non-irradiated bulbs produced plants with bloom as normal. However, irradiated bulbs showed retarded growth and did not flower. Bulbs of 'New Wave' and 'Tiny Dino' irradiated with 125Gy gamma rays survived, but their growth rate dropped considerably. Part or whole leaves of the other cultivars except 'New Wave' and 'Tiny Dino' withered. Moisture content of individual scale was 72~78% depending on cultivar. Bulblet formation from untreated scales was 100%. Among all irradiated scales only 'Siberia' scales showed 8.5% bulblet formation when irradiated with 50Gy gamma rays. Pollen germination as affected by gamma ray irradiation had no consistent tendency. When dosage of $F_1$ 'Augusta' seeds reached 300Gy, their survival ratio was drastically decreased. Bulblet formation in vitro was observed only in non-irradiated seeds. Lethal dose ($LD_{50}$) of seed was less than 100Gy. Height and width of $F_1$ 'Augusta' bulblets in vitro irradiated with gamma rays decreased as dosage increased regardless of the culture method. The percentage shoot formation was 100% in non-irradiated bulblets and 15~60% in irradiated ones.

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.165-168
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• 1995

The embryos formed from anther culture of peony exhibited divergent morphologies. The frequency of normal embryos with two cotyledons was about two times higher in the embryos formed through direct embryogenesis than those formed from callus. About 69% of the embryos with two cotyledons converted into normal plants, but convention rate of the abnormal embryos with one and three or four cotyledons was only 4 to 9%. The embryos of hem and bowling pin shape did not undergo development into normal plants.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.49-59
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• 2009

Seasonal changes of the growth characteristics and biomass of Scirpus fluviatilis, a aquatic emergent vascular plant, were investigated to reveal the phenology and the population dynamics and to provide the fundamental resources for the restoration counterplan of the wetland vegetation in the littoral zone of the Upo wetland, Changnyeong-gun, Gyeongsangnam-do, Korea from March 2006 to November 2006. Scirpus fluviatilis was distributed commonly in Upo, Mokpo, Sajipo, Jokjibyeol, and Topyeongcheon upstream and downstream of Upo wetland, and the density was highest in Mokpo. Distribution range for the water depth was 9~49cm, and the highest shoot density in 26~49cm, and the mean shoot density was $119/m^2$, and the mean shoot length was 122.3cm on May 28. The number of the tuber was $104.5/0.25m^2$, and the living tubers were 84.2%. The mean fresh biomass of the living tubers was 3.0g, and those of 1~4g was most as 57.9%. Germination rates of the living tubers was 43.8%, and the maximum rate was in 7~9g and more than 10g. In the pot cultivation, the shoot density of the germinated tubers and the dormant tubers were highest as 13.5 and 9.7, respectively in early August. In the field study, the shoot density had few change before typhoon damage, while the density increased abruptly in November after flooding accompanied with the typhoon 'Ewiniar'. The shoot length in the pot cultivation and in the field study were 100~116cm and 60~170cm, respectively in the growth-end. Biomass allocation rates into the stem, leaf, flower, and underground parts were 8.9%, 6.6%, 0%, and 84.5%, respectively in the pot cultivation of the germinated tubers, and those of the dormant tubers were 7.1%, 7.1%, 0%, and 85.8%, respectively. The tuber number increased to 1.4~4.1 times by the growth-end, so it is concluded that Scirpus fluviatilis is mostly propagated by the vegetative reproduction.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.261-266
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• 1995

This study was carried out to develop new varieties which are dwarf and tolerant to winter cold in the Aurantioideae by intergeneric crossing. to do that, the reciprocal crosses of Hwanggeumyooza and trifoliate orange, yooza and trifoliate orange were done and in vitro immature ovule culture of their hybrid was carried out .The callus formation from immature ovule was good in order of Hwanggeumyooza, Hwanggeumyooza $\times$ tifoliate orange, yooza, and trifoliate orange and best at 1 to 3 mg/L NAA+0.5mg/L zeatin on MT medium. In vitro germination percentage of 20week old hybrid of Hwanggeumyooza $\times$ tifoliate orange and trifoliate orange $\times$ Hwanggeumyooza were 41.3% and 37.7, respectively. The phenotype of hybrid (95%) of Hwanggeumyooza $\times$ trifoliate orange and that (100%) of trifoliate orange $\times$ Hwanggeumyooza were similar to that of trifoliate orange. After Hwanggeumyooza was pollinated by pollens of trifoliate orange, the pollen tubes grew on stigma after 3h of pollination and entered into micropyle after about 24~28 h. One gamete in pollen was fused with polar nuclei after 2 days and other one fused with egg nucleus at 3days after pollination. The fruit set percentage by intergeneric crossing was 14.0% in Hwanggeumyooza $\times$ trtfoliate orange and 17.5% in trifoliate orange $\times$ Hwanggeumyooza. The fruit set percentages of Hwanggeumyooza. and trifoliate orange were 34.2% and 39.5% by artificial self-fertilization, 34.2% and 39.5% by artificial cross fertilization, 3.1% and 1.4% by parthenocarpy and 13.0% and 3.0% by natural fertilization, respectively. The somatic and gametic chromosome numbers of Hwanggeumyooza, yooza, and trifoliate orange were 2n=18 and n=9.

• Korean Journal of Plant Resources
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• v.25 no.2
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• pp.285-292
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• 2012

Self-incompatibility (SI) system is a genetic barrier that prevents self-fertilization and promotes cross-pollination among different S genotypes. In many of these species, SI is controlled by a single genetic locus known as S locus, which prevents the fertilization by pollen with same locus. S RNases are the products of the S-locus expressed in the stylar tissue of Fuji Apple with gametophytic self-incompatibility system. This study investigated the various types of chemicals in order to select more effective inhibitors and activators. The effect on the inhibition of S RNase of Fuji apples was investigated $in$ $vitro$. The result showed that the enzyme activity was reduced 24.3% by Iron(II) Sulfate, significantly. $In$ $vitro$ studies of pollen growth tube showed that pollen tube growth had a higher germination rate (90%) in 10% Sucrose than in 2% sucrose extension medium. Data on the fruit set of apples treated with inhibitor and activator. Double application of $A^+$(Apple Plus, ISTECH Co. Ltd.,)+Vitamin B6 had the highest central fruit set as 86.1%(Andong). One time application of $A^{++}$Vitamin B1 in Yeongju obtained the highest central fruit set (91.9%).

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.294-299
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• 2003

The seeds of naturally growing Heteropappus hispidus (Thunb.) were treated by nine different doses (0, 10, 20, 40, 80, 120, 160, 200, 300, 400 Gy) of gamma rays to investigate their germination rate and to quantity the characteristics of their germinated plants as like as leaf appearance and length, the formation rate of anthocyanin color in stem 30 days after germination, the formation rate of rosette leaf and multi-shoot, the flowering and seed-bearing, and shoot length. The germination rate at least up to 120Gy was not greatly affected but was rapidly decreased at over 160Gy. It seemed that lethal dose ($LD_{50}$) of germination was 160Gy. The leaf appearance and growth was also inhibited, but the formation rate of anthocyanin color in the flower stem was enhanced up to 30% with dose. The rosette plants were observed in plants irradiated with higher than 40Gy. Multi-shoots were developed over 80Gy. For a short shoot length and bundle of thin stem, it was considered that they can be selected as the potential pot flower plants, through genetic fixation. In particular, it was suggested that the formation of anthocyanin color in flower stem, rosette and multi-shoot plants induced by the high dose of gamma rays could be utilized as the morphological markers for the mutant selection of Heteropappus hispidus (Thunb.).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.424-428
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• 2003

This study was conducted to find out the optimum cultural method for hybrid seed production of Chalok 2. Higher seed yield was obtained when KW3 was used as a seed parent (female). KW7 was shown Higher barren stalk occurrence which caused significant seed yield reduction when it was used as a seed parent (female). The ratio of female (KW3) to male (KW7) rows with 4 to 1 had higher seed yield than that of 2:1 or 3:1. In case of using KW3 toy a seed parent, KW3 was susceptible to stem and ear rotting disease. The 35th day after silking was optimal period to harvest due to higher 100-grain weight, lower rotten grain, and higher germination rate.