• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.48-51
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• 2005

Karyotype analysis and chromosomal locailization of 45S and 5S rDNAs using McFISH (multi-color fluorescence in situ hybridization) were carried out in Jeffersonia dubia Benth., which is one of medicinal plants belonging to Berberidaceae. The somatic metaphase chromosome number was 2n=2x=12 and the size of chromosomes ranged $1.95{\sim}3.50\;{\mu}m$. The chromosome complement consisted of two pairs of metacentrics (chromosomes 1 and 3), two pairs of submetacentrics (chromosomes 2 and 4) and two pairs of subtelocentrics (chromosomes 5 and 6). In McFISH, one pair of 45S rDNA site was detected on the centromeric region of chromosome 2 and three pairs of 5S rDNA sites were detected on the short arm of chromosomes 4, 5 and 6, respectively.

• Journal of Plant Biotechnology
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• v.31 no.2
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• pp.103-108
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• 2004

This study was carried out to develop the efficient methods for the subsequent progeny of intersectional hybrid between Oriental and Asiatic lily hybrids. The pollen fertility and germination ability of 3 different allotetraploids (OAOA) after somatic chromosome doubling was ranged from 0 to 80 percent on artificial pollen germination medium. The number of BC$_1$ progeny using allotetraploid of F$_1$ OA-hybrid as male and female parent was different. The efficiency of BC$_1$ progeny production was increased when F$_1$OA-hybrids was used as male rather than as female parent. And in back crosses of F$_1$ OA-hybrids with the Asiatic and Oriental hybrids, Asiatic hybrids showed higher efficiency on BC$_1$ progeny production. The ploidy level between 2x or 4x Asiatic hybrid and allotetraploid F$_1$ OA-hybrid was determined and showed higher progeny production in 2x-4x crosses rather than 4x-4x.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.1-10
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• 1997

Unreduced (2n) gametes are meiotic products (pollen or egg) having a sporophytic (somatic) chromosome number, resulting from abnormalities during either microsporogenesis or megasporogenesis. They occur naturally at a low frequency in many plant species. Unreduced (2n) gametes in plants can be identified for four possible ways as follow i) pollen size and/or shape differences between haploid (n) and diploid (2n) pollen, ii) ploidy analysis (chromosome number) of progeny or meiotic analysis (presence of dyads andlor triads at the microspore stage), iii) progeny performance and fertility and iv) dosage of isozyme and DNA markers. Unreduced (2n) gametes can be an effective breeding tool in synthesizing new cultivars, providing a unique method to maximizing heterozygosity, i.e., transferring a large proportion of the non-additive genetic effects (intra- and inter- locus interactions) h m parent to offspring and can also be used to overcome infertility of interploidy crosses. Sexual polyploidization through 2n gametes has been a major route to the formation of naturally occurring polyploids. The three mechanisms of 2n pollen formation in potato have been discovered as follow: i) parallel spindles (ps) or tripolar spindles (ts), ii) premature cytokinesis (pc-I, pc-2) and iii) synaptic mutants (sy-2, sy-3, sy-4). Genetic analysis indicated that the mechanisms of 2n gamete formation were controlled by single recessive gene in potato, alfalfa, red clover, etc., and by two recessive genes in wheat. The use of 2n gametes which can efficiently transfer germplasm fiom wild relatives to cultivated species, especially fiom diploid to tetraploid could make a contribution to the improvement of germplasm base in breeding programs.

• Korean Journal of Plant Taxonomy
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• v.39 no.3
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• pp.193-198
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• 2009

Chromosome analysis using karyotyping and bicolor FISH were carried out for two Maackia species (M. fauriei and M. amurensis) found in Korea. The somatic metaphase chromosome number was 2n = 2x = 18 in both, and the size of these chromosomes ranged from 3.58 to $5.82{\mu}m$. The chromosome complements consisted of two pairs of metacentric (chromosomes 1 and 7), four pairs of submetacentrics (chromosomes 4, 6, 8 and 9) and three pairs of subtelocentrics (chromosomes 2, 3 and 5) in M. fauriei but, chromosomes 4 (subtelocentric) and 7 (submetacentric) of M. amurensis have different morphology. Using bicolor FISH, a pair of 45S rDNA loci were observed for both M. fauriei and M. amurensis, but the number and site of the 5S rDNA signal were different in the two species. M. fauriei has two pairs of 5S signals on chromosomes 7 and 8 but, M. amurensis has four paris on chromosomes 3, 4, 7 and 7. Hence, the 5S rDNA is a useful FISH for Maackia species.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.131-144
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• 1995

To determine the structure of chromosome and to identify the sex chromosome of Ginkgo biloba and G. biloba var. fastigiata, the samples were obtained from root tips of trees growing in seven different provinences. The results are as follows. The basic number of somatic chromosomes was 2n=24. The range of a relative length of long chromosome was between $14.88{\sim}11.18{\mu}m$ and that of short chromosome was $8.11{\sim}6.24{\mu}m$. The chromosome sets were composed with one long pairs of m type and 11 short pairs of sm or st type. These short pairs showed the continuous descending in length. There was a satellite on the short arm of the Longest chromosome pair, and were satellites of the one or both long arm of 7th or 8th chromosome pair which were sm or st type, or the shortest st type chromosome pair. Sometimes, a satellite on the short arm of the longest chromosome pairs of Ginkgo biloba was double satellite, but that of G. biloba var. fastigiata was not. Karyotype was $2n=24=2^{2s}A^m+2B^{st\;or\;sm}+2C^{st}+2D^{st}+2E^{st}+2F^{st\;or\;sm}+2G^{sm}+2^{2s}H^{sm}\;or\;(^{1s}H^{sm}+H^{sm})+2I^{st}+2J^{st}+2K^{st}+2^{2s}L^{st}\;or\;(^{1s}L^{st}+L^{st})$. The male and female trees were not apparently distinguished by the chromsome structures. However the differences between the satellites could be used to identify the male and females. The male tree has double satellite on short arm of a longest chromosome pairs and females' has not. Also female trees have a satellite on a short chromosome more frequently than male trees.

• Korean Journal of Medicinal Crop Science
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• v.12 no.6
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• pp.490-493
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• 2004

Karyotypes were established in five Pulsatilla species from Korea : P. cernua, P. davurica, P. koreana, P. chinensis and P. tongkangensis. The somatic chromosome numbers of five species were all 2n=2x=16 with the basic number of x=8. The chromosome complement of P. cernua consisted of 5 pairs of metacentric, 1 pair of submetacentric and 2 pairs of subtelocentric. P. davurica, P. koreana and P. chinensis consisted of 5 pairs of metacentric and 3 pairs of subtelocentric. P. tongkangensis consisted of 5 pairs of metacentric, 2 pairs of submetacentric, and 1 pair of subtelocentric. Karyotype formulas of P. davurica, P. koreana, and P. chinensis were the same as K (2n) = 2x = 16 = 10m + 6st, while those of P. cernua was K (2n) = 2x = 16 = 10m + 2sm + 4st and P. tongkangensis was K (2n) = 2x = 16 = 10m + 4sm + 2st, respectively.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.442-448
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• 2010

The objectives of this study were to analyze mutant lines of Chinese cabbage ($Brassica$ $rapa$ ssp. $pekinensis$) using gene tagging system (plasmid rescue and inverse polymerase chain reaction) and to observe the phenotypic characteristics. Insertional mutants were derived by transferring DNA (T-DNA) of $Agrobacterium$ for functional genomics study in Chinese cabbage. The hypocotyls of Chinese cabbage 'Seoul' were used to obtain transgenic plants with $Agrobacterium$ $tumefaciens$ harboring pRCV2 vector. To tag T-DNA from the Chinese cabbage genomic DNA, plasmid rescue and inverse PCR were applied for multiple copies and single copy insertional mutants. These techniques were successfully conducted to Chinese cabbage plant with high efficiency, and as a result, T-DNA of pRCV2 vector showed distinct various integration patterns in the transgenic plant genome. The polyploidy level analysis showed the change in phenotypic characteristics of 13 mutant lines was not due to variation in somatic chromosome number. Compared with wild type, the $T_1$ progenies showed varied phenotypes, such as decreased stamen numbers, larger or smaller flowers, upright growth habit, hairless leaves, chlorosis symptoms, narrow leaves, and deeply serrated leaves. The polyploidy level analysis showed the change in phenotypic characteristics of 13 mutant lines was not due to variation in somatic chromosome number. To tag T-DNA from the Chinese cabbage genomic DNA, plasmid rescue and inverse PCR were applied for multiple copies and single copy insertional mutants. Mutants that showed distinct phenotypic difference compared to wild type with 1 copy of T-DNA by Southern blot analysis, and with 2n = 20 of chromosome number were selected. These selected mutant lines were sequenced flanking DNA, mapped genomic loci, and the genome information of the lines is being recorded in specially developed database.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.4
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• pp.305-312
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• 1992

This experiment was carried out to investigate seed set, variation in chromosome number, and agronomic characteristics of the progeny in the cross between hexaploid triticale variety, Sinkihomil(P$_1$) and tetraploid rye variety, Dooroohomil(P$_2$). Seed set rate obtained was 30.5% in the cross of Sinkihomil with Dooroohomil, whereas 3.26% in reciprocal cross using Dooroohomil as female. Alsoseed set was 8.75% in F$_1$/P$_1$, 7.20% in F$_1$/P$_2$, and 1.53% in F$_2$(=F$_1$ /F$_1$, respectively. Germination rate of crossed seed was 37% in cross of P$_1$ with P$_2$, 39.0% in F$_1$/P$_1$(BC$_1$), 50% in F$_1$/P$_2$(BC$_2$) and 43.0% in F$_1$/F$_1$(F$_2$), and 1,000 grain wight was 20.7g in the cross of P$_1$ with P$_2$, which have 41.9g and 47.7g, respectively, 24.5g in F$_1$/P$_1$, 23.6g in F$_1$/P$_2$, and 24.5g in F$_1$/F$_1$, respectively. In pollen fertility of F$_1$ plant, 69.8% turned out to be abnormal or sterile pollen grains, whereas 30.2% was fertile or normal. In meiosis of pollen mother cell of F$_1$ plant, 13.5 univalents, 8.89 bivalent and 1.24 trivalent were appeared. Somatic chromosome number of 35 in F$_1$, both 32 to 33 and 35 to 36 in F$_2$, 35 to 39 in BC$_1$ and 28 to 36 in BC$_2$ which mean producing female gamate was 14 to 18 chromosome in PMC of F$_1$ plant. Rate of fertile plant turned out to be 100% in F$_1$, 4.5% in F$_2$, 42.9% in BC$_1$, and 50.0% in BC$_2$, respectively. Number of seed set per spike appeared to be 1.17 in F$_1$ plant, 13.3 in F$_2$, 2.36 in BC$_1$, and 3.75 in BC$_2$, respectively. Days to heading of F$_1$ was intermediate, but F$_2$ was later than both parents. Plant height of F$_1$ , BC$_1$ ,and BC$_2$ was shorter than both parent, but F$_2$, longer than both parents.

• Korean Journal of Medicinal Crop Science
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• v.13 no.3
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• pp.118-121
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• 2005

Karyotypes were established in seven Angelica species cultivated in Korea. The somatic chromosome numbers were 2n = 2x = 22 with the basic number of x = 11 in all Angelica plants examined. Their metaphase chromosomes ranged from 3.56 ${\mu}M$. to 8.91 x. in length. Distinctive Karyotypes were found in two species, A. tenuissima with all metacentries, K(2n) = 2x = 22m, and A. genuflexa with all subtelocentrics, K(2n) = 2x = 22st. Karyotype formulas of A. gigas, A. acutiloha, A. sinensis, A. decursiva and A. dahurica were K(2n) = 2x = 20m + 2sm, K(2n) = 2x = 12m + 10sm, K(2n) = 2x = 16m + 6sm, K(2n) = 2x = 18m + 4sm and K(2n) = 2x = 10m + 10sm + 2st, respectively. Cytological data showed that chromosomal polymorphisms within species were observed in Angelica plants compare to other regions.

• 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.