• 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.

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.39-49
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• 2007

We investigated to understand the differences in the karyotypes and the reproductive characteristics between the diploid clam, Corbicula japonica in the brackish water and the triploid clam, C. fluminea in the freshwater. The number of chromosomes of the diploid C. japonica were 38, which can be grouped into 19 pairs of two homologues. These can be divided into 11 pairs of telocentric, 4 pairs of subtelocentric, 3 pairs of submetacentric and one pair of metacentric chromosomes. C. japonica is oviparous and dioecious. The clam has two pairs of gills, with the inner and outer-demibranchs, however, they do not act mainly as marsupia. External fertilization occurs in the brackish water. The triploid marsh clam, C. fluminea has 54 chromosomes, which can be grouped into 18 sets of three homologues. These 18 sets can be divided into one metacentric group, five submetacentric groups and 12 subtelo- or telocentric groups. C. fluminea is ovoviviparous and functional hermaphrodite. The triploid condition may be closely related to hermaphroditism. This species has the inner-demibranchs acting mainly as marsupia. The depletion of ripe eggs occurred in the inner-demibranchs of the gill during the incubatory periods, and ripe eggs produced in the hermaphroditic follicles in the gonad during the non-incubatory periods. The gonad developmental stages of two marsh clams (C. japonica and C. fluminea) can be divided into five stages: early active stage, late active stage, ripe stage, partially spawned stages, and spent/inactive stage.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.198-203
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• 2013

Herein we analyzed the nuclear DNA content and the histological characteristics of the triploid of the 'Hyunsasi' (Populus alba ${\times}$ P. glandulosa $F_1$) which were developed for biomass production and molecular breeding research. The flow cytometric analysis showed that the nuclear DNA content of the 3 triploids were 1.6 times greater than those of the diploid. In terms of histological characteristics, the cross-section area of the stem of 'Line-18' was 1.6 times larger than that of the diploid. The area of pith, and cortex and phloem of the stem of 'Line-18' was also 1.6 and 2.0 times larger than that of the diploid, respectively. Moreover, the length and area of guard cell of 'Line-18' was 1.2 times larger than that of the diploid. These results helps to understand the cytological characteristics of the triploid poplar clones, and further investigations in the growth rate and wood properties of the triploids growing in the field will determine whether the triploid poplars are good candidates for molecular breeding programs and for the improvement of industrial biomass productivity.

• Korean Journal of Ichthyology
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• v.28 no.4
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• pp.215-222
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• 2016

Triploidy was induced in the marine medaka, Oryzias dancena by cold shock treatment ($0^{\circ}C$) of fertilized eggs for 30, 45, or 60 min, applied two minutes after fertilization. The triploid genotype was induced by each of the thermal shock regimes tested. The best result was obtained when the eggs were treated for 45 min, which induced triploidy in all the resulting fish. Triploidy was confirmed using chromosomal and flow cytometer analyses, and erythrocyte measurements. The surface areas and volumes of the erythrocytes of triploid fish were significantly larger than those of diploid fish, and their chromosome number (3N=72) was 1.5 times greater that for the diploids (2N=48). Based on a flow cytometer analysis, the triploid fish had approximately 1.5 times the cellular DNA content (2.40 pg/cell) of the diploid specimens (1.61 pg/cell). Data from this study provide the basis for the development of unique models for studying reproductive confinement in transgenic fish.

• 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.

• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.299-304
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• 1986

The cell volume, cell surface, cell concentration, dry cell weight, frequence of respiratory deficient mutation, resistance against ultraviolet irradiation, fermentation power, DNA contents of haploid diploid, triploid and tetraploid of Saccharomyces cerevisiae strain were investigated. Respiratory deficient mutants by spontaneous mutation were absolved more frequently in the haploid than in the diploid, triploid and tetraploid. And cell volume, cell surface, cell concentration, dry cell weight, resistance against ultraviolet irradiation, fermentation power, and DNA contents were significantly increased as the ploidy increased.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.92.2-92
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• 1997

No Abstract, See Full Text

• 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.

• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.97-101
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• 1994

The fertilities of pyloploidy mulberries and the germination abilities and shape of poliploidy mulberry seeds fructified by natural cross were investigated and the results are as follows. Regarding the size of seeds, that of the tetraploid was the biggest and that of hexaploid was the smallest among the investigated polyploids. Those of diploid and triploid ranged between those of tetraploid and hexaploid. The fertilization rates of the varieties of Shinkwangppong and Cheongunppong, which were triploid, were 25.4 and 55.0%, respectively, and Shinkwangppong showed 10.2% of cross rate, but Cheongunppong did not have germination ability. The tetraploid seeds showed 61~68% of fertility and 30~54% of cross rate. The Puksan No. 2, which is hexaploid, had about 43% and 7% in fertility and cross rate, respectively. The germination abilities of floating seeds of diploid and tetraploid were comparatively high, but the floating seeds of triploid and hexaploid did not have germination ability. The seeds of diploid had a high fertility of 81~95% and a comparatively high cross rate of 47~74%.

• Korean Journal of Ichthyology
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• v.6 no.2
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• pp.206-221
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• 1994

Morphometrical data for diploid and induced triploid cherry salmon, Oncorhynchus masou were analyzed prior to the spawning season to compare their commercial values. The following traits were measured with the diploids and induced triploids : ungutted and gutted body weight; body length; dressing percentage; condition factor; gonad weight and gonad index; belly thickness; viscera weight; viscera index; body circumference at the pelvic, dorsal and anal fins; area of the cross sections at the pelvic and dorsal fins; two belly thickness traits measured on each cross section; total height, height and width of each cross section; three body shape traits; and nine cross section shape traits. Body length and body weight of diploids were larger than those of induced triploids and dressing percentage, gonad weight, gonad index, viscera index, and liver index were also larger in diploids. However, induced triploids showed higher values in one belly thickness trait and some section shapes than diploids. Differences in body traits were due to the sterility of induced triploids. Therefore, induced triploid cherry salmon appears to have greater potentials for the commercial values than their diploids.