• Korean Journal of Plant Taxonomy
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• v.40 no.3
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• pp.153-156
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• 2010

The somatic chromosome number of four Korean species of Leontopodium were investigated. The chromosome number of L. leiolepis (2n = 24) is reported here as for the first time. The chromosome number of L. japonicum (2n = 28) is not varied among the 3 populations on the Korean Peninsula, but that condition is different from the previous reports for Korea (2n = 26) and Japan (2n = 21, 26). L. hallaisanense and L. japonicum, both of which are in sect. Nobilia and similar to each other in gross morphology, have the same chromosome number of 2n = 28. On the other hand the chromosome number of Korean L. leontopodioides (2n = 24) is different from that in Russian reports (2n = 26). The chromosome numbers of all Korean species of the genus Leontopodium could be inferred as tetraploid or aneuploid.

• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.178-186
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• 2022

The tetraploid Solanum acaule is a wild potato species from Bolivia widely used for potato breeding because of its diverse attractive traits, including resistance to frost, late blight, potato virus X, potato virus Y, potato leafroll virus, potato spindle tuber viroid, and cyst nematode. However, the introgression of useful traits into cultivated potatoes via crossing has been limited by differences in endosperm balance number between species. Somatic fusion could be used to overcome sexual reproduction barriers and the development of molecular markers is essential to select proper fusion products. The chloroplast genome of S. acaule was sequenced using next-generation sequencing technology and specific markers for S. acaule were developed by comparing the obtained sequence with those of seven other Solanum species. The total length of the chloroplast genome is 155,570 bp, and 158 genes were annotated. Structure and gene content were very similar to other Solanum species and maximum likelihood phylogenetic analysis with 12 other species belonging to the Solanaceae family revealed that S. acaule is very closely related to other Solanum species. Sequence alignment with the chloroplast genome of seven other Solanum species revealed four InDels and 79 SNPs specific to S. acaule. Based on these InDel and SNP regions, one SCAR marker and one CAPS marker were developed to discriminate S. acaule from other Solanum species. These results will aid in exploring evolutionary aspects of Solanum species and accelerating potato breeding using S. acaule.

• Journal of Plant Biotechnology
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• v.50
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• pp.34-44
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• 2023

The tetraploid Solanum hjertingii, a wild tuber-bearing species from Mexico is a relative of potato, S. tuberosum. The species has been identified as a potential source of resistance to blackening for potato breeding. It does not exhibit enzymatic browning nor blackspot which are physiological disorders. However, due to their sexual incompatibility, somatic hybridization between S. hjertingii and S. tuberosum must be used to introduce various traits from this wild species into potato. After somatic hybridization, molecular markers are essential for selecting fusion products. In this study, the chloroplast genome of S. hjertingii was sequenced by next-generation sequencing technology and compared with those of other Solanum species to develop specific markers for S. hjertingii. The chloroplast genome has a total sequence length of 155,545 bp, and its size, gene content, order and orientation are similar to those of the other Solanum species. Phylogenic analysis including 15 other Solanaceae species grouped S. hjertingii with S. demissum, S. hougasii, and S. stoloniferum. After detailed comparisons of the chloroplast genome sequence with eight other Solanum species, we identified one InDel and seven SNPs specific to S. hjertingii. Based on these, five PCR-based markers were developed for discriminating S. hjertingii from other Solanum species. The results obtained in this study will aid in exploring the evolutionary aspects of Solanum species and accelerating breeding using S. hjertingii.

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.18-25
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• 2021

Solanum demissum is one of the wild Solanum species originating from Mexico. It has wildly been used for potato breeding due to its resistance to Phytophthora infestans. S. demissum has an EBN value of four, which is same as that of S. tuberosum, so that it is directly crossable for breeding purposes with the cultivated tetraploid potato (S. tuberosum). In this study, the chloroplast genome sequence of S. demissum obtained by next-generation sequencing technology was described and compared with those of seven other Solanum species to develop S. demissum-specific markers. Thetotal sequence length of the chloroplast genome is 155,558 bp, and its structural organization is similar to those of other Solanum species. Phylogenetic analysis with ten other Solanaceae species revealed that S. demissum is most closely grouped with S. hougasii and S. stoloniferum followed by S. berthaultii and S. tuberosum. Additional comparison of the chloroplast genome sequence with those of seven other Solanum species revealed two InDels specific to S. demissum. Based on these InDels, two PCR-based markers for discriminating S. demissum from other Solanum species were developed. The results obtained in this study will provide an opportunity to investigate more detailed evolutionary and breeding aspects in Solanum species.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.131-140
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• 2020

Solanum stoloniferum, one of the wild tetraploid Solanum species belonging to the Solanaceae family, is an excellent resource for potato breeding owing to its resistance to several important pathogens. However, the sexual hybridization of S. stoloniferum with S. tuberosum (potato) is hampered due to the sexual incompatibility between the two species. To overcome this and introgress the various novel traits of S. stoloniferum in cultivated potatoes, cell fusion can be performed. The identification of the fusion products is crucial and can be achieved with the aid of molecular markers. In this study, the chloroplast genome sequence of S. stoloniferum was obtained by next-generation sequencing technology, and compared with that of six other Solanum species to identify S. stoloniferum-specific molecular markers. The length of the complete chloroplast genome of S. stoloniferum was found to be 155,567 bp. The structural organization of the chloroplast genome of S. stoloniferum was similar to that of the six other Solanum species studied. Phylogenetic analysis of S. stoloniferum with nine other Solanaceae family members revealed that S. stoloniferum was most closely related to S. berthaultii. Additional comparison of the complete chloroplast genome sequence of S. stoloniferum with that of five Solanum species revealed the presence of six InDels and 39 SNPs specific to S. stoloniferum. Based on these InDels and SNPs, four PCR-based markers were developed to differentiate S. stoloniferum from other Solanum species. These markers will facilitate the selection of fusion products and accelerate potato breeding using S. stoloniferum.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.141-149
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• 2020

Solanum hougasii, one of the wild Solanum species, has been widely used in potato breeding since it exhibits excellent resistance to diverse important pathogens. S. hougasii can be directly crossed with the cultivated tetraploid potato (S. tuberosum) owing to its EBN (Endosperm Balanced Number) value of 4, which is same as that of S. tuberosum although it is an allohexaploid. In this study, the complete chloroplast genome sequence of S. hougasii was obtained by next-generation sequencing technology, and compared with that of the chloroplast genome of seven other Solanum species to identify S. hougasii-specific PCR markers. The length of the complete chloroplast genome of S. hougasii was 155,549 bp. The structural organization of the chloroplast genome in S. hougasii was found to be similar to that of seven other Solanum species studied. Phylogenetic analysis of S. hougasii with ten other Solanaceae family members revealed that S. hougasii was most closely related to S. stoloniferum, followed by S. berthaultii, and S. tuberosum. Additional comparison of the chloroplast genome sequence with that of five other Solanum species revealed five InDels and 43 SNPs specific to S. hougasii. Based on these SNPs, four PCR-based markers were developed for the differentiation of S. hougasii from other Solanum species. The results obtained in this study will aid in exploring the evolutionary and breeding aspects of Solanum species.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.1-10
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• 1997

Unreduced (2n) gametes are meiotic products (pollen or egg) having a sporophytic (somatic) chromosome number, resulting from abnormalities during either microsporogenesis or megasporogenesis. They occur naturally at a low frequency in many plant species. Unreduced (2n) gametes in plants can be identified for four possible ways as follow i) pollen size and/or shape differences between haploid (n) and diploid (2n) pollen, ii) ploidy analysis (chromosome number) of progeny or meiotic analysis (presence of dyads andlor triads at the microspore stage), iii) progeny performance and fertility and iv) dosage of isozyme and DNA markers. Unreduced (2n) gametes can be an effective breeding tool in synthesizing new cultivars, providing a unique method to maximizing heterozygosity, i.e., transferring a large proportion of the non-additive genetic effects (intra- and inter- locus interactions) h m parent to offspring and can also be used to overcome infertility of interploidy crosses. Sexual polyploidization through 2n gametes has been a major route to the formation of naturally occurring polyploids. The three mechanisms of 2n pollen formation in potato have been discovered as follow: i) parallel spindles (ps) or tripolar spindles (ts), ii) premature cytokinesis (pc-I, pc-2) and iii) synaptic mutants (sy-2, sy-3, sy-4). Genetic analysis indicated that the mechanisms of 2n gamete formation were controlled by single recessive gene in potato, alfalfa, red clover, etc., and by two recessive genes in wheat. The use of 2n gametes which can efficiently transfer germplasm fiom wild relatives to cultivated species, especially fiom diploid to tetraploid could make a contribution to the improvement of germplasm base in breeding programs.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.297-302
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• 2006

In general, the proliferation of orchids via somatic embryos has been used for mass production of somatic clones because of high propagation efficiency. In spite of high propagation rate, this method often brings somaclonal variation, especially polyploid frequency. Therefor we here concentrated to investigate the relationship between endopolyploidization patterns of explants and the occurrence of tetraploid variant in clonally proliferated Doritaenopsis via somatic embryo regeneration system. In the fully developed somatic embryo, upper part contained 2C to 16C while middle and lower parts showed 2C to 32C DNA content. Two-week-old embryo contained 2C to 16C, whereas those regenerated after 4 to 10-week-old contained 2C to 64C nuclei. Results showed that endoreduplication was variable depending upon tissue types, ages, and parts in one species. lower part of somatic embryo having high endoreduplication degree increased the regeneration of tetraploid variants by about 3-fold comparing to upper part of somatic embryo culture. polyploid frequency occurrence might be closely related to the high levels of endoreduplication of somatic embryos used as explant. It suggested that the upper part of somatic embryo having comparatively low endoreduplication degree is suitable for the stable in vitro propagation system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.790-799
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• 1997

Aegilops genus is known to include the donor species of the Band D genome of the bread wheat(ABD). An effort to establish a better strategy for phylogenetic relationships about Aegilops polyploids by AFLPs(Amplified Fragment Length Polymorphisms) was conducted using the 19 Aegilops sPP. and T. aestivum. The 207 polymorphic bands from the amplified products on the 6% acrylamide denaturing sequencing gels were obtained with the 7 AFLP primer combinations, and used to account for the genetic similarities and cluster analysis using NTSYS program. According to the genome analysis, the $M^h$-genome of Ae. heldreichii was estimated as an intermediate genome between the M-genome of Ae. comosa and N-genome of Ae. uniaristata and supposed to be incorporated in the establishing process of UM-genome as a possible diploid donor. And Ae. ventricosa(DN) was more close to Ae. umbellulata(U) than Ae. squarrosa(D). The close relationship between Ae. squarrosa and T. aestivum was perceived as a diploid donor of D-genome. As for the polyploid species, hexaploid Ae. triaristata was more closely related to Ae. columnaris rather than tetraploid Ae. triaristata. The clustered groups were, basically same to the previous Gihara's sections based on phenotypes and pairing analysis of interspecific hybrids. AFLP was evaluated as an efficient and powerful method in the genome evaluation of closely related species.

• Journal of Korean Society of Forest Science
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• v.77 no.3
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• pp.338-350
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• 1988

In order to solve the taxonomic problems of the genus Juniperus growing in South Korea, an identification key of the genus and species was developed bayed un flower structure, cane and seed shape, branching habit, tree form, leaf characteristics etc. of the 7 native species and the a exotic cultivars. The typical pattern of karyotype found by chromosome analysis of the species was used for the identification among morphologically similar species. The length of chromosome were ranged $9{\sim}15{\mu}m$ in all studied specie. J. chinensis, var. procumbens, and var. kaizuka sere tetraploid, 4n=44, var. globosa, var. procumbens, var. horizontalis, J. virginiada, J. rigida, J. rigida var. longicarpa, and J. coreana were diploid, 2n=22. The species in the Sabina section showed large variation in the length of chromosome and kinetochore position. The species in the Oxycedrus section showed the cytological characteristics that the 11th chromosome t-type(acrocentric), and the m-type abundant chromosome set was relatively uniform as compared to those of the Sabina section. The species in the Sabina section, which are planted in the large city area, show great morphological variation because many different ecotypes were mixed and often crossed among them. In summary, this study was able to make clear identification and to find out similarity among Juniperus, species by the morphological and cytological analysis.