• Korean Journal of Breeding Science
• /
• v.42 no.5
• /
• pp.502-506
• /
• 2010

Soybean seed possesses about 15 allergenic proteins recognized by IgEs from soy-sensitive human. The allergenic impact of soybean proteins limit its extensive usage in a broad range of processed foods. Soybean protein P34 or Gly m Bd 30k of the cysteine protease family is one of the major allergen of the soybean seed. P34-null soybean, PI567476, was identified among soybean (Glycine max & Glycine soja Sieb. and Zucc) of approximately 16,226 accessions from USDA soybean germplasm screened. Also, for P34 gene (Williams 82; whole genome sequence cultivar) and P34 null gene (PI567476) comparative analysis of sequences listed in the NCBI database showed the presence of a SSLP (Simple Sequence Length Polymorphism) of 4 base pair. So, a SSLP marker was designed to reveal the polymorphism of the locus. In this study, a population of 339 $F_2$ recombinant inbred lines generated by cross between Taekwang (Glycine max) and PI567476 was used to select $F_{2:3}$ plant of a P34 null gene. The result separation rate Taekwang type, heterozygous type and PI567476 type were shown in 85: 187: 67 since single gene is concerned in as the separation rate of 1:2:1 in $X^2{_{0.05}}=5.99$, df=2. In future, selected plant will identify protein level, whether P34 null protein is equal to P34 null gene.

• Journal of Ginseng Research
• /
• v.33 no.3
• /
• pp.199-205
• /
• 2009

Ginseng (Panax ginseng C.A. Meyer) is one of the most important medicinal plants in East Asia. Microsatellite or simple sequence repeat (SSR) markers are used in obtaining genetic analysis and authentication in many plants. The present study examined five microsatellites in conjunction with P. ginseng in Korea. The total observed allelic number was 17 (mean = 3.4), and gene diversities varied from 0.078 to 0.543 with an average of 0.314. Through a combined analysis of five loci in 100 ginseng samples, 44 different combined genotypes were observed. Expected and observed heterozygosites ranged from 0.077 to 0.541 (mean = 0.313) and 0.040 to 0.130 (0.083), respectively. All examined loci exhibited deficiency of heterozygosity and deviation from the Hardy-Weinberg equilibrium. Such results may be explained by the non-random mating and inbreeding that has occurred for several hundred years. These microsatellite markers could be used for the study of molecular genetics and the establishment of DNA marker database, as well as authentication of ginseng species and chromosomal mapping of QTL loci in P. ginseng.

• Journal of Plant Biotechnology
• /
• v.43 no.3
• /
• pp.261-271
• /
• 2016

Citrus is an economically important fruit crop widely growing worldwide. However, citrus production largely depends on natural hybrid selection and bud sport mutation. Unique botanical features including long juvenility, polyembryony, and QTL that controls major agronomic traits can hinder the development of superior variety by conventional breeding. Diverse factors including drastic changes of citrus production environment due to global warming and changes in market trends require systematic molecular breeding program for early selection of elite candidates with target traits, sustainable production of high quality fruits, cultivar diversification, and cost-effective breeding. Since the construction of the first genetic linkage map using isozymes, citrus scientists have constructed linkage maps using various DNA-based markers and developed molecular markers related to biotic and abiotic stresses, polyembryony, fruit coloration, seedlessness, male sterility, acidless, morphology, fruit quality, seed number, yield, early fruit setting traits, and QTL mapping on genetic maps. Genes closely related to CTV resistance and flesh color have been cloned. SSR markers for identifying zygotic and nucellar individuals will contribute to cost-effective breeding. The two high quality citrus reference genomes recently released are being efficiently used for genomics-based molecular breeding such as construction of reference linkage/physical maps and comparative genome mapping. In the near future, the development of DNA molecular markers tightly linked to various agronomic traits and the cloning of useful and/or variant genes will be accelerated through comparative genome analysis using citrus core collection and genome-wide approaches such as genotyping-by-sequencing and genome wide association study.

• Horticultural Science & Technology
• /
• v.31 no.5
• /
• pp.580-589
• /
• 2013

This study was carried out to evaluate the suitability of microsatellite markers for varietal identification and genetic relationship of 170 commercial pepper cultivars. The relationship between marker genotypes and 11 pepper cultivars with different morphological traits was also analyzed. Of the 302 pairs of microsatellite primers screened against 11 pepper cultivars, 24 pairs were highly polymorphic in terms of number of alleles. These markers were applied for the construction of DNA profile data base for 170 commercial pepper cultivars. A total of 164 polymorphic amplified fragments were obtained from 24 microsatellite primers. The average polymorphism information content was 0.673 ranging from 0.324 to 0.824. One hundred and sixty four microsatellite alleles were used to calculate Jaccard's distance coefficients using unweighted pair group method. A clustering group of varieties, based on the results of microsatellite analysis, were categorized into 3 major groups corresponding to morphological traits. The phenogram discriminated all varieties by markers genotypes. These microsatellite markers will be useful as a tool for protection of plant breeders' intellectual property rights through variety identification in distinctness, uniformity and stability test.

• Horticultural Science & Technology
• /
• v.33 no.5
• /
• pp.722-729
• /
• 2015

Powdery mildew (PM) caused by Podosphaera aphanis is a major disease that can result in significant yield losses in strawberry (Fragaria ${\times}$ ananassa Duchesne). For preventing PM, pesticides are usually applied in strawberry. In this study, molecular markers were developed to increase breeding efficiency of PM-resistance cultivars by marker-assisted selection (MAS). An $F_2$ population derived from a cross between PM-resistance 'Seolhyang' and PM-susceptibility 'Akihime' was evaluated for disease resistance to PM and RAPD (random amplification of polymorphic DNA)-BSA (bulked segregant analysis). Among 200 RAPD primers tested, OPE10 primer amplified a 311bp-band present in with 331bp. Sequence alignment performed for searching polymorphisms and six single nucleotide polymorphism (SNP) were found in amplified regions. To develop polymorphic marker for distinguishing between resistant and susceptible, RAPD was converted to cleaved amplified polymorphic sequence (CAPS) marker. Among restriction enzymes associated with six SNPs, Eae I (Y/GGCCR) was successfully digested to 231bp in susceptible. The results suggest that the selected CAPS marker could be used for increasing efficiency of selecting powdery mildew resistant strawberry in breeding system.

• Horticultural Science & Technology
• /
• v.31 no.3
• /
• pp.344-351
• /
• 2013

Microsatellite is one of the most suitable marker for cultivar identification as it has great discrimination power for cultivars with narrow genetic variation. The polymorphism level between 358 microsatellite primer pairs and 11 commercial cucumber cultivars was investigated. Thirty-one primer pairs showed high polymorphism within cucumber cultivars with different fruit types. These markers were applied for the constructing DNA profile data base of 110 commercial cucumber cultivars through multiplex PCR and fluorescence based automatic detection system. A total of 139 polymorphic amplified fragments were obtained by using 31 microsatellite markers. The average of PIC value was 0.610 ranging from 0.253 to 0.873. One hundred and thirty nine microsatellite loci were used to calculate Jaccard's distance coefficients for UPGMA cluster analysis. A clustering group of varieties, based on the results of microsatellite analysis, were categorized into plant shape and fruit type. Almost the cultivars were discriminated by marker genotypes. This information may be useful to compare through genetic relationship analysis between existing variety and candidate varieties in distinctive tests and protection of plant breeders' intellectual property rights through variety identification.

• Journal of Plant Biotechnology
• /
• v.42 no.4
• /
• pp.326-335
• /
• 2015

Citrus is an economically important fruit tree with the largest amount of fruit production in the world. It provides important nutrition such as vitamin C and other health-promoting compounds including its unique flavonoids for human health. However, it is classified into the most difficult crops to develop new cultivars through conventional breeding approaches due to its long juvenility and some unique reproductive biological features such as gamete sterility, nucellar embryony, and high level of heterozygosity. Due to global warming and changes in consumer trends, establishing a systematic and efficient breeding programs is highly required for sustainable production of high quality fruits and diversification of cultivars. Recently, reference genome sequences of sweet orange and clementine mandarin have been released. Based on the reference whole-genome sequences, comparative genomics, reference-guided resequencing, and genotyping-by-sequencing for various citrus cultivars and crosses could be performed for the advance of functional genomics and development of traits-related molecular markers. In addition, a full understanding of gene function and gene co-expression networks can be provided through combined analysis of various transcriptome data. Analytic information on whole-genome and transcriptome will provide massive data on polymorphic molecular markers such as SNP, INDEL, and SSR, suggesting that it is possible to construct integrated maps and high-density genetic maps as well as physical maps. In the near future, integrated maps will be useful for map-based precise cloning of genes that are specific to citrus with major agronomic traits to facilitate rapid and efficient marker-assisted selection.

• Horticultural Science & Technology
• /
• v.30 no.1
• /
• pp.64-72
• /
• 2012

Phytophthora root rot has been causing a serious yield loss in pepper production. Since 2004, the year in which commercial cultivars resistant to the disease were firstly commercialized, it has been necessary to introduce the resistance into domestic pepper cultivars for dried red pepper. Therefore, developing molecular markers linked to the resistance is required for an accurate selection of resistant plants and increasing breeding efficiency. Until now, several markers associated with the major dominant gene resistant to Phytophthora root rot have been reported but they have some serious limitations for their usage. In this study, we aimed to develop molecular markers linked to the major dominant gene that can be used for almost of all genetic resources resistant to Phytophthora root rot. Two segregating $F_2$ populations derived from a 'Subicho' ${\times}$ 'CM334' combination and a commercial cultivar 'Dokyacheongcheong' were used to develop molecular markers associated with the resistance. After screening 1,024 AFLP primer combinations with bulked segregant analysis, three AFLP (AFLP1, AFLP2, and AFLP3) markers were identified and converted into three CAPS markers (M1-CAPS, M2-CAPS, and M3-CAPS), respectively. Among them, M3-CAPS marker was further studied in ten resistants, fourteen susceptibles, five hybrids and 53 commercial cultivars. As a result, M3-CAPS marker was more fitted to identify Phytophthora resistance than previously reported P5-SNAP and Phyto5.2-SCAR markers. The result indicated that the M3-CAPS marker will be useful for resistance breeding to Phytophthora root rot in chili pepper.

• Horticultural Science & Technology
• /
• v.35 no.1
• /
• pp.98-107
• /
• 2017

A DNA profile database was constructed to investigate the genetic relatedness of 72 germplasm samples of Pyrus and related cultivars using microsatellite markers. Three P. pyrifolia, four P. commus, and one P. betulifolia cultivars with different morphological traits were screened using 387 pairs of microsatellite primers. A core set of 11 primer pairs was selected to obtain 133 polymorphic amplified fragments meeting three criteria: high polymorphism information contents (PIC), high repeatability, and distinct allele patterns. The number of alleles per locus ranged between 4 and 22. Average PIC was 0.743 (range: 0.557 - 0.879). Cluster analysis using the unweighted pair - group method with arithmetical average (UPGMA) separated the 72 pear cultivars and germplasm samples into four major groups: Chinese, European pears, and a cluster of 55 Asian pears that could be reclassify into two subcluster, I - $1^{st}$ and II - $2^{nd}$, according to pedigree information. Almost all of the cultivars were discriminated by 11 microsatellite marker genotypes. The microsatellite DNA profile database may be utilized as tool to verify distinctness, uniformity, and stability between candidate cultivar, and to verify in the distinctness of existing cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.4
• /
• pp.448-457
• /
• 2015

Developing rice lines with various amylose contents is necessary to diverse usages of rice in terms of raw materials for processed food production, and thereby to promote rice consumption in Korea. A rice mutant line, 'Namil(SA)-dull1' was established through sodium azide mutagenesis on 'Namil', a non-glutinous Korean Japonica rice cultivar. Namil(SA)-dull1' had dull endosperm characteristics and the evaluated amylose content was 12.2%. A total of 94 F2 progenies from a cross between 'Namil(SA)-dull1' and 'Milyang23', a non-glutinous Tongil-type rice cultivar, was used for genetic studies on the endosperm amylose content. Association analyses, between marker genotypes of 53 SSR anchor markers and evaluated amylose contents of each 94 F2:3 seeds, initially localized rice chromosome 6 as the harboring place for the modified allele(s) directing low amylose content of 'Namil(SA)-dull1'. By increasing SSR marker density on the putative chromosomal region followed by association analyses, the target region was narrowed down 0.94 Mbp segment, expanding from 28.95 Mbp to 29.89 Mbp, on rice chromosome 6 pseudomolecule. Among the SSR loci, RM7555 explained 84.2% of total variation of amylose contents in the $F_2$ population. Further physical mapping on the target region directing low amylose content of 'Namil(SA)-dull1' would increase the breeding efficiency in developing promising rice cultivars with various endosperm characteristics.