• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.70-71
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• 1990

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.10a
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• pp.34-35
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• 1990

• 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 CROP SCIENCE
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• v.27 no.3
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• pp.243-246
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• 1982

A proposal of gene transfer scheme from diploid to hexaploid in oats was described. The main idea of this scheme are (1) use Avena magna which has two genomes partially in common with two genomes of the hexaploid Avena sativa or a common genome and the rest genomes partially commonn, and which lead to more regular pairing between them rather than AABB genome type to get 6x-amphiploid as a bridge between ploidy level. Cross between Avena strigosa and Avena magna is compatible and further give 42% seed set, (2) extract tetraploid derivatives which have in corporated desired genes from Avena strigasa to Avena magna, (3) Synthetic petaploid provide 2n=21 chromosome number in female gametes, which lead to complete pairing or nearly so in progenies with Avena sativa, (4) eventually homozygous lines will be produced by selfing the heterozygous (regarding to$A^{As}$ genome) at final step.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.226-235
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• 1991

This experiment was carried out to obtain the information on the crossability, germination rate, and pollen viability of the progeny from the cross between hexaploid triticale cv. Sinkihomil and five hexaploid wheat varieties. The results are summarized as follows. Seed set was 28.8 to 41.8% (ave-raged 34.1%) in the cross between triticale and wheat, which resulted in 3.61% in F$_2$(selfed F$_1$), 3.99% in F$_1$/P$_1$ 21. 9% in F$_1$/P$_2$ respectively. However, seed set was extremely low in reciprocal crosses when triticale was used as male. In the backcross, crossability was higher in F$_1$/wheat and triticale/F$_1$ than that in wheat/F$_1$ and F$_1$/triticale, respectively. Germination rate of the crossed seed was 95% in F$_1$ 66.3% in F$_2$ (selfed F$_1$), 62.0% in F$_1$/P$_1$ and 81.0% in F$_1$/P$_2$ from the cross between triticale and wheat, respectively. When triticale cv. Sinkihomil was used as male, seeds were degenerated because of the failure of endorsperm development. This might be caused by AAABBBDDR genome constitution in the cytoplasm from a hexaploid wheat. Pollen fertility of F, plant was averaged 34.1% in the cross between triticale and wheat. Significant positive correlation between the pollen fertility and seed set rate in the cross between triticale and wheat were detected.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.333-333
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• 2022

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.310-318
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• 1991

This experiment was carried out to obtain the information on the variation of chromosome number in pollen mother cell (PMC) and somatic cell of the progeny from the cross between hexaploid triticale cv. Sinkihomil and five hexaploid wheat varieties. The results were summarized as follows: Number of uni-, bi- and tri-valent in PMC was 11.9, 14.4 and 0.44, respectively, in the F$_1$ between triticale and wheat. Significant positive correlation between the pollen fertility and seed set rate, pollen fertility and bivalent number of PMC, and seed set rate and bivalent number of PMC, and negative correlation between pollen fertility and uni-or tri-valent of PMC in the cross between triticale and wheat were detected. F$_1$ (crossed seed) had 42 chromosomes, F$_2$ and F$_1$/P$_1$ showed high frequency of hyperploid (42-49) and F$_1$/P$_2$ showed high frequency of hypoploid (36- 42), which suggest non-random segregation for somatic chromosome number. in the cross between the triticale and wheat.

• Proceedings of the Korean Society of Crop Science Conference
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• 2007.11a
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• pp.35.2-35.2
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• 2007

• Horticultural Science & Technology
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• v.33 no.6
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• pp.869-876
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• 2015

Wild relative species of domesticated crops are useful genetic resources for improving agronomic traits. Cytogenetic investigations based on chromosome composition provide insight into basic genetic and genomic characteristics of a species that can be exploited in a breeding program. Here, we used FISH analysis to characterize the ploidy level, chromosome constitution, and genomic distribution o f 5S and 4 5S r ibosomal DNA (rDNA) in four wild Cucurbitaceae species, namely, Citrullus lanatus (Thunb.) Mansf. var. citroides L. H. Bailey (2n = 22), Melothria japonica Maxim. (2n = 22), Sicyos angulatus L. (2n = 24), and Trichosanthes kirilowii Maxim. (2n = 66, 88, 110 cytotypes), collected in different areas of Korea. All species were diploids, except for T. kirilowii, which included hexa-, octa-, and decaploid cytotypes (2n = 6x = 66, 8x = 88, and 10x = 110). All species have small metaphase chromosomes in the range of $2-5{\mu}m$. The 45S rDNA signals were localized distally compared to the 5S rDNA. C. lanatus var. citroides and M. japonica showed one and two loci of 45S and 5S rDNA, respectively, with co-localization of rDNA signals in one M. japonica chromosome. S. angulatus showed two co-localized signals of 5S and 45S rDNA loci. The hexaploid T. kirilowii cytotype showed five signals each for 45S and 5S rDNA, with three being co-localized. This is the first report of hexaploid and decaploid cytotypes in T. kirilowii. These results will be useful in future Cucurbitaceae breeding programs.

• Molecules and Cells
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• v.25 no.2
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• pp.163-171
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• 2008

The genus Cynodon comprises ten species. The objective of this study was to evaluate the genetic diversity of Korean bermudagrasses at the morphological, cytological and molecular levels. Morphological parameters, the nuclear DNA content and ploidy levels were observed in 43 bermudagrass ecotypes. AFLP markers were evaluated to define the genetic diversity, and chromosome counts were made to confirm the inferred cytotypes. Nuclear DNA contents were in the ranges 1.42-1.56, 1.94-2.19, 2.54, and 2.77-2.85 pg/2C for the triploid, tetraploid, pentaploid, and hexaploid accessions, respectively. The inferred cytotypes were triploid (2n = 3x = 27), tetraploid (2n = 4x = 36), pentaploid (2n = 5x = 45), and hexaploid (2n = 6x = 54), but the majority of the collections were tetraploid (81%). Mitotic chromosome counts verified the corresponding ploidy levels. The fast growing fine-textured ecotypes had lower ploidy levels, while the pentaploids and hexaploids were coarse types. The genetic similarity ranged from 0.42 to 0.94 with an average of 0.64. UPGMA cluster analysis and principle coordinate analysis separated the ecotypes into 6 distinct groups. The genetic similarity suggests natural hybridization between the different cytotypes, which could be useful resources for future breeding and genetic studies.