• Journal of Sericultural and Entomological Science
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• v.42 no.2
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• pp.67-72
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• 2000

Autotetraploid 'Sawonppong 26'was induced by dropping clochicine solution in growing point of Keomseolppong which is of high rootability and some agronomic charactelistics are as follows. Sawonppong 26 is a tetraploid of Keomseolppong with 56 of the chromosome number. Its fertlization percent was 59.4% and the germination percent of sank seed was normal. Sugar degree of mulberry fruit was 13.3% and total acidity was 0.69%. Single fruit weight of Sawonppong 26 was increased by 79%, as compared to that of Keomseolppong. Even though percent of survival of hard wood cutting was 94%, number of rootings was less and diameter of root was slender, it is expectedly a promising variety to be used for a breeding parent from the aspect of rootability.

• Korean Journal of Plant Taxonomy
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• v.47 no.4
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• pp.304-307
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• 2017

We report somatic chromosome numbers for three species belonging to the Euphorbia pekinensis complex distributed in Far East Asia. In E. pekinensis populations distributed in Korea, 2n = 28 and 56 were found, while the Japanese native E. lasiocaula was also found at 2n = 28 and 56 and the Japanese endemic E. sinanensis was found at 2n = 20. Based on the number of chromosomes, E. lasiocaula distributed in Japan supports treatment as a variety of E. pekinensis rather than as a different species, while E. sinanensis should be recognized as a distinct species rather than as a variety of E. pekinensis. In the same populations of E. pekinensis and E. lasiocaula, diploid and tetraploid individuals were found, and the diversity of these chromosome numbers was consistent with the morphological diversity of these populations, suggesting the future evolutionary potential of this species.

• Journal of Plant Biology
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• v.38 no.4
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• pp.321-328
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• 1995

Calli obtained from basal disc explants of Allium victorialis var.platyphyllum wre grown in three kinds of nutrient media (MS, BDS, and B5), and the frequencies of mitotic index and the chromosomal aberrations were analysed. The mitotic index varied from 0.55% to 1.01% with respect to culture media and ages. The mitotic irregularities like micro-, bi- and multi-nuclei, chromosome bridge and laggards were noted in each types of calli. The chromosome number variations observed in metaphase stage were identified aneuploid and tetraploid. Structural variations such as dicentric chromosomes, centromere breakage and small chromosomes were observed. Relationship between basal medium and chromosomal variability was not observed in this study. But, in BDS medium, NAA and BA had a more effect on number variation than kinetin.

• 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 Breeding Science
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• v.42 no.1
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• pp.28-34
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• 2010

Diversity of 30 Korean potato cultivars was evaluated using 14 microsatellite markers. Twelve microsatellite markers representing 12 loci in the potato genome detected 84 polymorphisms among 30 cultivars and revealed alleles with a mean of 7.00 alleles per primer. The polymorphism information content (PIC) value ranged from 0.57 to 0.93 with average of 0.82. Based on polymorphism, cluster analysis was conducted by the unweighted pair-group method with arithmetic average (UPGMA) methods. Thirty potato varieties were distinctly separated into 2 groups and similarity coefficient of cluster ranged from 0.58 to 0.95. Thirty tetraploid cultivars were evaluated for six important agronomic traits. One-way analysis of variance was done to look for the degree of relationships between individual markers and traits. K1 and K2 markers showed a significant association with amylose contents, starch contents, and specific gravity.

• Korean Journal of Plant Taxonomy
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• v.52 no.4
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• pp.219-225
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• 2022

To elucidate the ancestry of the allopolyploids E. stevenii and E. boöphthona, I examined eleven isozyme loci and 24 morphological characters from 28 populations representing five related Euphorbia species from Australia. According to an analysis of genetic and morphological data, three diploid species differentiated recently, but two independent polyploid species are estimated to have differentiated a relatively long time ago. Fixed heterozygosity for most isozymes in E. stevenii and E. boöphthona strongly suggests that these two species are allopolyploids rather than autopolyploids. The isozyme profiles of E. stevenii indicate that it is an allopolyploid that evolved from interspecific hybridization between the diploid E. tannensis and unidentified or extinct tetraploid species. In addition, isozyme patterns strongly suggest that E. stevenii was one of the ancestors of E. boöphthona. However, E. boöphthona showed a large number of fixed alleles that were not detected in any other Australian Eremophyton species. The most likely hypothesis for the origin of E. boöphthona is that it was formed by hybridization and chromosomal doubling between an extinct diploid species and the hexaploid E. stevenii.

• Korean Journal of Plant Taxonomy
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• v.39 no.1
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• pp.42-47
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• 2009

In this study, the somatic chromosome of 14 taxa of Korean Galium L. were investigated. Among them were a few taxa for which the somatic chromosome number was determined for the first time. The somatic chromosome numbers of Korean Galium L. were 2n = 22, 24, 44, 48, 66, 72, 77, 88 and so basic chromosome numbers were x = 11 or 12. Those taxa having the basic chromosome number x = 11 showed polyploidy, including diploid, tetraploid, heptaploid, and octoploid. Tetraploid and hexaploid can be observed in those taxa with the basic number x = 12. The eleven taxa reported 11 for the first time are G. spurium var. echinospermon (Wallr.) Hayek (2n = 44), G. gracilens (A. Gray) Makino (2n = 22), G. pogonanthum Franch. & Sav. (2n = 22, 44), G. trachyspermum A. Gray (2n = 22, 44), G. japonicum (Maxim.) Makino & Nakai (2n = 77), G. trifloriforme Kom. (2n = 44), G. dahuricum Turcz. var. dahuricum (2n = 48, 72), G. dahuricum var. tokyoense (Makino) Cufod. (2n = 22), G. kinuta Nakai & Hara (2n=66), G. verum var. trachycarpum for. nikkoense (Nakai) Ohwi (2n = 44), G. verum var. asiaticum for. pusillum (Nakai) M. Park (2n = 44). The taxa with the same chromosome numbers as previously reported ones were G. boreale L. (2n=22) and G. verum var. asiaticum Nakai for. asiaticum (2n = 44). The chromosome number of G. trifidum L. (2n = 22) was different from the previous report. Two infraspecific taxa of G. dahuricum showed differences in their basic chromosome numbers (x = 11 for G. dahuricum Turcz. var. dahuricum and x = 12 for var. tokyoense (Makino) Cufod. The somatic chromosome number for G. dahuricum Turcz. var. dahuricum was found to be 2n = 48 (tetraploid) or 72 (hexaploid), while that of G. dahuricum var. tokyoense (Makino) Cufod. was found to be 2n = 22 (diploid). Therefore, basic chromosome numbers for members of the genus Galium can be used as valuable characters in delimiting infrageneric sections and investigating interspecific relationships.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.4
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• pp.209-215
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• 2020

A winter forage tetraploid rye (Secale cereale L.) cultivar, 'Daegokgreen', was developed at the Department of Central Area Crop Science, NICS, RDA in 2016. The mutant line 'CG11003-8-B', which was induced from rye cultivar 'Gogu' (diploid) by colchicine treatment, was selected for its excellent agronomic performance and was placed in preliminary yield trials for one year, 2013. The line was designated "Homil59" and was tested for regional yield trials at the four locations in Korea from 2014 to 2016. Finally, the new cultivar was named as the 'Daegokgreen' (grant number 8274). The leaf of cultivar 'Daegokgreen' is wide, long and dark-green color. The cultivar also has a big-size grain with light-brown color. The heading date of cultivar 'Daegokgreen' was April 17 which was 2 days later than that of check cultivar 'Gogu'. The tolerance to cold and wet injury, and resistance to powdery mildew and leaf rust of the new cultivar were similar to those of the check cultivar but the resistance to the lodging of the new cultivar was stronger than that of the check. The average roughage fresh and dry matter yield of the new cultivar after 10 days from heading were 37.0 and 7.7 MT ha-1, respectively, which were similar to those (38.4 and 8.0 MT ha-1) of the check cultivar. The roughage quality of 'Daegokgreen' was higher in crude protein content (8.9%) than that of the check cultivar (7.9%), while was similar to the check in total digestible nutrients (56.9%). This cultivar is recommended for fall sowing forage crops at all of crop cultivation areas in Korea.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.239-246
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• 1994

The genotypic (2n, 3n, 4n) response of watermelon in vitro shoot tip culture was evaluated. Different genotypes had similar response in terms of shoot formation and growth. Shoot formation was better at lower concentration of 0.3 mg/L BA and higher concentration of 5-10.0 mg/L 2iP and kinetin, but growth of newly formed shoot was inhibited. With further subculture, kinetin did not promote shoot formation Better shoot formation was observed at 0.3-0.5 mg/L BA. Combination of 0.3 mg/L BA and 0.3-0.5 mg/L BA was effective in shoot multiplication, growth and induction of more internodes. Varrying levels of light intensity and agar concentration did not affect the performance of tetraploid plants. Higher light intensity and agar concentrations decreased the number of shoot formed in triploid plane. Growth in both genotype, however was inhibited. Higher light intensity was found to promote leaf senescence in all genotypes. All growth inhibitors decreased the number of shoots formed and slowed plant growth there by prolonging duration of cultures. Growth inhibitors were to observed to decrease incidence of hyperhydricity in culture. No difference in shoot formation was observed in each of the concentrations used in Ancymidol, TIBA, CCC and PP333. Shoot formation and growth was more inhibited in ABA treatments. Leaf expansion and growth was poor in all treatments.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.617-622
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• 2011

The study was conducted to determine the efficiency in producing spontaneous polyploids in some mandarin hybrids with different seed embryony. Seed formation by open pollination, frequency of spontaneous polyploids, and plant growth characteristics were evaluated in four mandarin hybrids with polyembryony such as 'Amakusa', 'Haruka', 'Hayaka', and 'Seminole' and two with monoembryony such as 'Benibae' and 'Harehime'. The mean number of the developed seeds per fruit was 10.0 and frequency of small seeds was 25.1%. Polyploids were selected from plants germinated in vitro by a flow cytometry and confirmed by chromosome analysis. One triploid was produced from 'Harehime', one tetraploid, 'Amakusa', and one tetrapoid, 'Benibae'. There were little differences in leaf shape, thickness, petiole length, and internode length between diploids and polyploids such as tri- or tetraploid. However, polyploids had larger stomata and lower density of stomata in abaxial epidermis than diploids. SPAS indicating chlorophyll content and photosynthetic rate were significantly affected by ploidy level. The results indicated that spontaneous polyploids might be produced by open pollination in some mandarin hybrids and monoembryony had higher frequency in polyploid occurrence than polyembryony.