• Plant Resources
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• v.6 no.3
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• pp.188-194
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• 2003

Present studies were carried out to produce tetraploid plants by colchicine treatment using seeds, seedlings and shoot tips of Platycodon grandiflorum in Campanulaceae. The most successful colchicine treatment for tetraploid production in P. grandiflorum was soaking treatment using 0.01 and 0.5% colchicine solution for 1 hour and 12 hours, respectively. Morphological characteristics of both diploid and tetraploid were similar, but tetraploid plants had more leaves. Compared to diploid, tetraploid had the larger stomata, but less number of stomata. Fresh weight of tetraploids was 20∼40% heavier than that of diploid.

• Korean Journal of Plant Taxonomy
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• v.50 no.1
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• pp.17-21
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• 2020

Chrysanthemum indicum (Asteraceae) is a perennial plant belonging to the genus Chrysanthemum. The basic chromosome number of Chrysanthemum sensu stricto is x = 9, and it consists of a series of polyploids ranging from diploid to decaploid. However, C. indicum, which occurs in Korea, is known to consist of only tetraploids, except for two diploid populations that are sympatric with C. zawadskii and C. boreale. During the collection of plant materials as part of a study to ascertain the diversity of Chrysanthemum in Korea, we found new diploid populations (2n = 18) of C. indicum in the southern region of Korea and describe them here in detail.

• Korean Journal of Plant Taxonomy
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• v.51 no.1
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• pp.100-102
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• 2021

The chromosome number of myoga ginger (Zingiber mioga (Thunb.) Roscoe: Zingiberaceae) has been reported as 2n = 22 for Chinese plants and 2n = 55 for Japanese plants. We checked the chromosome number of Z. mioga in plants collected in Jeollabuk-do and Jeollanam-do, Korea, and counted 2n = 44, the first report of this number for the species. As the basic chromosome number of Z. mioga is thought to be x = 11, Z. mioga plants in China, Korea, and Japan appear to be diploids, tetraploids, and pentaploids, respectively. In finding the tetraploid race of Z. mioga in Korea, we can hypothesize that the pentaploid race in Japan is derived through the fertilization of reduced gametes of the diploid race and unreduced gametes of the tetraploid race.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.15-15
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• 2001

We recently demonstrated that satellite regions exhibit an aberrant DNA methylation in cloned bovine embryos. Here, we examined, using bisulfite -sequencing technology, whether the inefficient demethylation of cloned donor genomes could be rescued by the presence of oocytic nuclei. Both AciI digestion and sequencing analyses showed that satellite sequence was demethylated more efficiently in cloned tetraploid blastocysts than in diploid clones. When methyl -CpG density (the number of methyl-CpG sites per string) was scored, a significant decrease was observed In tetraploids (P<0.001). These results suggest that unknown mechanisms provided by oocytic nuclei could assist the demethylation of satellite sequences in tetraploid clones.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.810-817
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• 2010

We observed abnormal morphology of cotyledons occurring in seedlings derived from open-pollinated and cross-pollinated tetraploid grapes and selected aneuploids, especially hypo- and hyper-tetraploid in seedlings with abnormal morphology of cotyledons. Five types of morphologically abnormal cotyledons were observed. In open-pollination of four tetraploid grapes, the frequency of abnormal cotyledons was 1.6% (49 of 3029 seeds). Percentage of aneuploids in the seedlings of abnormal cotyledons was 20.4% (10 of 49 seedlings). Aneuploids in open-pollination consisted of three (4n = 4x-2), four (4n = 4x-1), and three (4n = 4x+1) seedlings. In cross-pollination of tetraploids, the frequency of abnormal cotyledons was 3.4% (59 of 1729 seeds). Percentage of aneuploids in the seedlings with abnormal cotyledons was 22.0% (13 of 59 seedlings). Aneuploids from cross-pollination of tetraploids consisted of two (4n = 4x-2), nine (4n = 4x-1), one (4n = 4x+1), and one (4n = 4x+3) seedlings. According to the results, although the abnormal cotyledon morphology of seedlings obtained from crossing between tetraploid grapes appeared at low rate (2.3%), aneuploid seedlings occurred at high rate (22.0%); therefore, it indicated that this selection strategy might be very efficient in the initial seedling stage.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.315-318
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• 1998

This study was conducted to clarify the acclimatization rate and ploidy level of anther culture-derived plants in broccoli. The acclimatization rate from 71.4 to 100% was obtained from 7 varieties in 2 years. It was possible to identify the ploidy of the Plants obtained through anther culture by measuring the number of chloroplast in the guard cell. The average numbers of chloroplasts per guard cell in haploid diploid, and tetraploid were 8.5, 13.5 and 18.5, respectively. The regenerated plants could be classified based on these results into 47.1-51.3% of haploids, 47.9∼51.7%, diploid, and 0.8∼l.2% of tetraploids.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.22-26
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• 1985

Cytological observations in the seven varieties of Juniperus chinensis L. showed three varieties (J. chinensis var. procumbens, J. chinensis var. kaizuka and J. chinensi.s var. aureo-variegata) were tetraploid with chromosome number, 2n=44, and rest of four varieties (J. chinensis var. horizontalis, J. chinensis var. sargentii, J. chinensis var. gtobosa and J. chinensis var. aureo-globosa) to be diploid, 2n=22. Chromosome configuration and behavior in the meiosis of P.M.C. of three tetraploids appeared to be slightly irregular. These results suggest that triploid tree can be artificially produced with these specific clones.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.113-116
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• 2001

Chromosomal variation was investigated in the female and male somaclones regenerated from the leaf segment culture of Rumex acetosa L. Difference in phenotype depending on the sexuality was not observed. In female somaclones, 21 among 25 somaclones carried the same chromosome complements (2n＝14) with wildtype and others were tetraploids (2n=28), Considerable chromosomal variation was found in male somaclones. Only 4 among 20 somaclones carried normal chromosome number (2n=15) and 13 somaclones were aneuploids.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.232-341
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• 2011

Pink snow mold, caused by Microdochium nivale, is a major disease on cool season turfgrasses in golf courses in northern Unites States. The relative susceptibility of 17 commercial cultivars of three bentgrass species (creeping, colonial and velvet bentgrass) to Microdochium nivale and the aggressiveness of M. nivale eight isolates obtained from infected turfgrasses on golf courses in Wisconsin were evaluated under controlled conditions. For the field trial, susceptibility of 2 year-old 12 commercial bentgrass cultivars was evaluated after inoculating three M. nivale isolates in the fields. There were significant differences in disease severities among the three bentgrass species, particularly between tetraploids (creeping and colonial) and diploid (velvet) species, and among cultivars within each species, indicating that there are varying levels of susceptibility in species and cultivars to M. nivale. Host resistance by days of cold hardening was confirmed, by detecting the resistance by 30 days of cold hardening treatments. In field trial, susceptibility of 12 bentgrass cultivars was highly correlated to the results obtained from growth chamber experiments. The positive correlation of the susceptibility between growth chamber experiments and field trials demonstrates that the growth chamber method is a useful technique for saving time, space and labor to evaluate efficiently pink snow mold susceptibility of bentgrass cultivars. This study could be applied to evaluating susceptibility of bentgrass to pink snow mold and also predicting a prospective evaluation of bentgrass cultivars to pink snow mold in fields in a breeding program.

• Korean Journal of Plant Taxonomy
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• v.41 no.1
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• pp.51-57
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• 2011

The microstructure of the leaf epidermis and trichomes of Fallopia sect. Reynoutria are examined using scanning electron microscopy. Fallopia sachalinensis was distinguished from other taxa in this section by its prominent epicuticular wax layer consisting of protruding wax rodlets. In addition, epicuticular rodlets of F. sachalinensis individuals from Ullung Island and Dok Island appear to be thinner than those from other regions, including Japan and Sakhalin. The stomatal size appears to be related to the ploidy level in the sect. Reynoutria, as the hexaploids, octoploids and dodecaploids tend to have larger stomata as compared to tetraploids. Three basic types of trichomes were found in the section; (1) conical unicellular trichomes, (2) uniseriate filiform trichome consisting of 1-8 cells, and (3) peltate glandular trichomes. The trichome types and their distribution appear to be useful in distinguishing the taxa in the section.