• Journal of Aquaculture
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• v.3 no.2
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• pp.135-144
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• 1990

Fertilized eggs of Oreochromis niloticus were subjected to cold treatments at $14^{\circ}C$ for 30, 45 and 60 minutes starting 5 minutes after insemination at $27^{\circ}C$. Ploidy levels were determined by chromosome preparations and the analysis of both cell and nuclear sizes. A temperature shock of $14^{\circ}C$ for 60 minutes yielded the best results ( $83.3\%$). Gonadal development in both sexes was severely retarded in all triploid groups at 6 months of age.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.100-108
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• 2010

This study was carried out to confirm the chromosome constitution and homoeologous recombination of progenies derived from various cross combination using tetraploid OA interspecific hybrid originated from mitotic chromosome doubling. Based on the chromosome analysis of progenies crossed reciprocally, there were only triploid progenies when crossed with diploid Asiatics as male or female parent. While only tetraploid progenies were produced when crossed tetraploid Asiatics or tetraploid OA hybrid with tetraploid OA hybrid, respectively. However, two types of progenies, that is, diploid and triploid plants, were produced from cross combinations between diploid Oriental hybrid and tetraploid OA hybrid. From the GISH analysis of OA hybrid, it was confirmed that diploid $F_1$ OA hybrid was consisted of 24 chromosomes (12 Oriental and 12 Asiatics) showing authentic OA hybrid. On the other hand, it was notified that triploid plants (3x=36) were consisted of 24 Asiatics lily chromosomes and 12 Oriental lily chromosomes by analysis of backcross progenies derived from either $A{\times}OA$ or $OA{\times}A$ crosses. In cross between tetraploid OA and OA, all the progenies were tetraploid with equal number of chromosomes without any homoeologous recombination, i.e. each 24 chromosomes of Oriental and Asiatics. In 2x-4x ($O{\times}OA$) cross combination, some progenies had 2x=24 chromosomes originated from only Oriental hybrid, and other progenies had 3x=36 chromosomes derived from 24 chromosomes of Oriental hybrid and 12 chromosomes of Asiatic hybrid. Only tetraploid Asiatics chromosomes without any Oriental one were produced in all the progenies from 4x-4x ($AA{\times}OA$) cross combination.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.291-296
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• 2012

Triploids are a useful tool for biomass production and molecular breeding of trees with a long life span. Triploids of the poplar 'Hyunsasi' (Populus alba ${\times}$ P. glandulosa) have been developed by crossing between female diploids and a male tetraploid. The tetraploid was developed around the 1970s at Korea Forest Research Institute by colchicine-induced chromosome doubling. Seedlings of the $F_1$ generation were analyzed using flow cytometry to verify their ploidy status. The mean relative fluorescence index of 3 F1 poplars, labeled as Line- 1, Line-17, Line-18, were approximately 1.5 times higher than those of diploid poplars, and the results clearly indicated that they were triploids. The phenotype of the F1 poplars included larger leaves and thicker stem than diploids, and abnormal leaf morphology, especially in the triploid 'Line-18'. Three triploid lines developed roots more slowly and had less roots than diploid. However, 3 poplar cytotypes (2x, Line-1, Line-17) rooted within 10 days on MS medium. In contrast, compared with the 3 cytotypes, the Line-18 showed about 80% and 70% in the rooting rate and the number of roots. The triploid poplars could be directly utilized for biomass production and with their sterility, they could serve as basic material for genetic transformation. In addition, flow cytometric analysis proved to be an effective and reliable method for screening forest trees for their ploidy level.

• Journal of Aquaculture
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• v.10 no.1
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• pp.39-47
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• 1997

Induction of hybrid and allotriploid between female rainbow trout, oncorhynchus mykiss and male cherry salmon, O. masou were performed. Triploid rate in allotriploid was 92% and the survival rates of allotriploid exceeded that of their hybrid counterparts. Karyological studies revealed that the hybrid had exactly the same intermediate diploid karyotypers as that of two parental species, while allotriploid had two sets of the maternal haploid complement and one set of the paternal haploid complement. Hybrid revealed an intermediate size in celluar and nuclear size of erythrocyte, while allotriploid revealed larger cellular and nuclear size of erythrocytes than hybrid. The number of nucleolar organizer regions of hybrid were 1 or 2, while those of allotriploids were 1, 2 or 3. These results proved that allotriploidization can lead to increase cytogenetical characters compared to counterpart hybridization.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.300-307
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• 2006

To clarify the morphological and geographical differentiation among the polyploid complexes of L. lancifolium collections in Korea, the mo게hological variation of 173 accessions were analyzed by ANOVA (one-way analysis of variance) and PCA (principal component analysis) on the basis of 38 morphological characters. 173m accessions were grouped into 78 diploids and 95 triploids by ploid levels and the triploids separated into 75 inland triploids (all around the Korea) and 20 island triploids (Backryung-do and Sochung-do, westemmost and northernmost islands of Korea) by geographic distribution and morphology. Island triploids showed significant morphological differences with inland triploids in ANOVA by many floral and leaf characters. In PCAs, diploids were separated from inland triploids by having longer plant height, smaller flower characters, higher pollen fertility and more stomata. The first four principal components accounted for 44.1% of the total variation. Plots of the island and inland groups for the first and second principal components separated each other with slight overlapping. Although the ploid forms are different between diploid and island triploid, island triploids were more closely overlapped with diploids by principal component 1 and 2 than inland triploids. This reflects that the whole external morphology of island triploids are similar to that of diploids. This, the phenotypic differentiation between inland and island triploids seems to be partly related to their geographical origins.

• Journal of Aquaculture
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• v.9 no.2
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• pp.133-140
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• 1996

Hybird and allotriploid between female rainbow trout (Oncorhynchus mykiss) and male coho salmon (O. kisutch) were produced by artificial fertilization and heat shocks. Hatching and survival rate of allotriploid at 2 month after hatching was $77.6\%$ and $54.5\%$ respectively, and these rates clearly exceeded those of their hybrid. Cell and nuclear sizes of the erythrocyte of hybrid were intermidiate of their parents and those of allotriploid were larger than thier hybird. The somatic chromosome number of viable hybrid was 2n = 60 and that of allotriploid was $90\~93$ with chromosomal polymorphism. Allotriploid karyotpe was constituted by two sets of rainbow trout chromosome and one set of coho salmon chromosome.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.656-664
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• 2015

To produce high quality watermelon, three tetraploid watermelon breeding lines (‘SA03-1’, ‘SA06-1’ and ‘SB01-1’) were developed by treatment with different chromosome doubling reagents. To identify the optimal tetraploid inductive conditions, the three watermelon breeding lines were selected by counting the number of doubled chloroplasts in guard cells. Tetraploid induction rates differed depending on the genotypes and treatment with doubling reagents. However, the highest induction rate occurred with 1.0% colchicine (82.2%). These putative tetraploid lines were re-confirmed for ploidy using flow cytometric analysis and chromosome counting. The internode length of the tetraploid breeding lines was different when the leaf size was larger in all three tetraploid lines compared to their diploids. The fruit weight of the tetraploid fruits for ‘SA03-1’ and ‘SB01-1’ was lower than for their diploid, and the rind thickness and total sugar content (°Brix) of tetraploid SB01-1 were significantly different from those of its diploid. Tetraploid lines were sterile, yielded a lower number of seeds per fruit for ‘SA03-1’ (21), ‘SA06-1’ (62), and ‘SB01-1’ (34.7), and the seeds were larger and thicker than those of their diploids. These tetraploid breeding results will be useful for breeding new seedless watermelon cultivars.

• FLOWER RESEARCH JOURNAL
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• v.18 no.4
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• pp.284-290
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• 2010

This study was carried out to breed a self-compatible variety of Tiger Lily from the seedlings originated from Chinju city, Gyeongsangnam-do. The morphological characteristics, ploidy, and the resistance of seedlings to virus infection were investigated. A progeny test was also conducted to examine whether the propagated progenies had the same characteristics as the mother plant. The self-compatible diploid lily variety developed in this study showed a tall type like native triploid lily, Lilium tigrinum, and bulbils were formed on both lily varieties. The morphological characteristics of the flowers and leaves were not much different between the varieties, while the size of the bulbils and bulbs showed significant differences. The percentage of seed generation by self-pollination was 72.6% for the self-compatible variety, while there was no seed generated for native triploid lily. The number of chromosome was 2n = 26 (x = 13, diploid) for the self-compatible variety, while 2n = 39 (x = 13, triploid) in native lily variety. The progenies of the self-compatible diploid lily variety showed the same characteristics as those of its mother plant in morphology, seed germination, and polyploidy. The mother plant of the self-compatible diploid lily variety showed 58% pollen germination and the 2-year-old and 3-year-old progenies showed similar germination percentages. The pollen grains of Korean native triploid lily, however, never germinated.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.761-770
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• 2016

This study investigated the variation in fruit characteristics between different triploid progenies derived from a cross between tetraploid and diploid grape cultivars, with the aim of developing high quality, labor-saving triploid grapes. No differences were found in fruit quality traits such as soluble solids content and titratable acidity, whereas significant variation was noted in cluster weight induced by a one-time application of GA3 (100 ppm) on the triploid progeny of different cross combinations. The cluster weight was higher in progeny obtained from 'Kyoho' ${\times}$ 'Sekirei' than for offspring derived from other cross combinations; deviation in the mean cluster weight was also small for 'Kyoho' ${\times}$ 'Sekirei' progeny. These results suggest that specific cross combinations, such as 'Kyoho' ${\times}$ 'Sekirei', can be used to efficiently breed new, labor-saving seedless grape cultivars.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.3
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• pp.161-168
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• 1989

To evaluate the quality of lipids and their fatty acid compositions in diploid and triploid carps(Cyprinus carpio), we analyzed the compositions of neutral lipid, phospholipid and glycolipid, and fatty acid contents of each lipids in these carp muscles. Total lipid contents of diploid carps, nonspawning season and spawning season, and triploid carp were $2.5\~3.0\%,\;1.4\~1.9\%\;and\;2.4\~3.1\%$, respectively. Regardless of belly and dorsal muscles, diploid carp of nonspawning season and triploid one were higher in neutral lipid, but lower in glycolipid and phospholipid than those of diploid one of spawning season. The neutral lipid and phospholipid were mainly consisted of triglyceride($66.9\~86.1\%$), and phosphatidyl-choline($55.6\~62.9\%$), respectively. In fatty acid compositions of total lipid, triploid carp showed higher content in monoenes such as 16: 1, 18: 1, but lower in polyenes such as 22:6 than those of diploid carp. The major fatty acids in total lipid were 18:1, 16:9, 18:2, 18:3 and 16:1 in order. The fatty acid compositions of neutral lipids showed similar trend to those of total lipid, and the major fatty acids in phospholipid were 16:0, 18:1, 18:2 and 22:6, These fatty acid compositions of neutral lipid, glycolipid and phospholipid were slightly difference between dorsal and belly muscles in all the carps.