• Journal of Life Science
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• v.22 no.3
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• pp.285-292
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• 2012

Genus Spiraea is composed of many long-lived woody species that are primarily distributed throughout Asia and Europe. In this study, we evaluated a representative sample of the 38 taxa in the world, including 14 in Korea, with nuclear ribosomal DNA internal transcribed spacer sequences (ITS) to estimate genetic relationships within the genus. The molecular data allowed us to resolve well-supported clades in the taxa. In 47 world accessions (38 taxa: 14 Korean taxa, 33 world taxa, and 9 overlapping taxa), total alignment length was 689 positions, of which 452 were parsimony informative, 527 variable, 75 singleton, and 159 constant characters. Although the phylogenic tree showed that many taxa of genus Spiraea were well separated from each other, many branches were not congruent with the morphological characteristics and geographical distributions of the genus. There were 430 segregating sites and the nucleotide diversity (${\pi}$) value was 0.281. Under the neutral mutation hypothesis, the probability that the Tajima test statistic (D) is positive (2.325) is more than 0.5. Therefore, there may be a site at which natural selection, which increases genetic variation, is operating.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.7-11
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• 2001

A total of 238 accessions of peppers (Capsicum spp.) were evaluated for resistance to powdery mildew (Leveillula taurica (Lev.) Arn) in 1998-1999. KC604, 605, 606 and 608 of C. baccatum, KC616 of C. chinense, and KC638, 640, 641, 642, 643 and 644 of C. pubescens were highly resistant and remained disease-free. KC47-1 (PI244670), KC319-1, KC545, KC320 showed only mild infection compared with susceptible control group, 'Chungok' and others. Therefore, they were considered moderately resistant. Among them, KC47-1, KC319-1 and KC320 are sources of resistance to gray leaf spot caused by Stemphylium spp. while KC47-1 is also resistant to bacterial leaf spot (Xanthomonas campestris pv. vesicatoria (Doidge) Dye). Therefore, they may be used in breeding for multiple resistance to those diseases.

• Journal of Sericultural and Entomological Science
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• v.45 no.2
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• pp.75-79
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• 2003

Fatty acids analysis was carried out with mulberry seed. As a result, palmitic acid, stearic acid, oleic cid and linoleic acid were detected as a major fatty acid. Their rates of composition were 8.8${\pm}$3.3, 4.2${\pm}$1.6, 5.8${\pm}$2.3 and 81.2${\pm}$6.9(％), respectively. The unsaturated fatty acids such as oleic acid and linoleic acid were abundant in mulberry seed. Paticularly, five accessions including ‘Gukkwang’, ‘Jaelaenosang’, ‘Sangbansibmunja (Jeonnam) ’, ‘Neunggeum’ and ‘Suwonnosang’ were observed only with linoleic acid. Unsaturated fatty acids are known to have physiological effects decreasing the serum cholesterol. From the above result, we confirm that mulberry fruits have abundant unsaturated fatty acids and anthocyanin pigments, and they are of great value as functional food resources.

• The Plant Pathology Journal
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• v.37 no.5
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• pp.428-436
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• 2021

Stem rot is a serious disease in Jerusalem artichoke (JA). To reduce the impact of this disease on yield and quality farmers often use fungicides, but this control method can be expensive and leave chemical residues. The objective of this study was to evaluate the efficacy of two biological control agents, Trichoderma harzianum T9 and Bacillus firmus BSR032 for control of Sclerotium rolfsii under field conditions. Four accessions of JA (HEL246, HEL65, JA47, and JA12) were treated or notreated with T. harzianum T9 and B. firmus BSR032 in a 4 × 2 × 2 factorial experiment in two fields (environments), one unfertilized and one fertilized. Plants were inoculated with S. rolfsii and disease was evaluated at 3-day intervals for 46 days. T. harzianum T9 and B. firmus BSR032 reduced disease incidence by 48% and 49%, respectively, whereas T. harzianum T9 + B. firmus BSR032 reduced disease incidence by 37%. The efficacy of T. harzianum T9 and B. firmus BSR032 for control of S. rolfsii was dependent on environments and genotypes. The expression of host plant resistance also depended on the environment. However, HEL246 showed consistently low disease incidence and severity index in both environments (fertilized and unfertilized). Individually, T. harzianum T9, B. firmus BSR032, or host plant resistance control stem rot caused by S. rolfsii in JA. However, no combination of these treatments provided more effective control than each alone.

• Korean Journal of Breeding Science
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• v.42 no.2
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• pp.144-150
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• 2010

The objective of this study was to map gene/QTL for photoblastism in a weedy rice (photoblastic rice: PBR) using DNA markers. Light-induced effect on germination of seeds was compared among three accessions (Oryza sativa L.), PBR, Milyang 23 and Ilpum. Results showed that PBR seeds started to show photoblastism during seed development, different from Ilpum and Milyang 23. Frequency distribution of germination in the F4 lines from crosses between Ilpum and PBR and, Milyang 23 and PBR revealed bimodal distributions suggesting that photoblastism was controlled by a few genes. Bulked segregant analysis using $F_4$ populations derived from the above two crosses was conducted to identify gene/QTL for photoblastism. Two QTL were identified on chromosomes 1 and 12 explaining 11.2 and 12.8% of the phenotypic variance, respectively. Two QTL were further mapped between two SSR markers, RM8260 and RM246 on chromosome 1, and between RM270 and 1103 on chromosome 12. It is noteworthy that two QTL for photoblastism were colocalized with the QTL for seed dormancy reported in the previous QTL studies. The clustering of two genes for photoblastism and dormancy possibly indicates that these regions constitute rice phytochrome gene clusters related to germination. Because PBR has a low degree of dormancy, a pleiotropic effect of a single gene controlling dormancy and photoblastism can be ruled out. The linked markers will provide the foundation for positional cloning of the gene.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.391-396
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• 2009

Perilla frutescens, which belonging to the Labiatae family, is widely cultivated oil crop and have been used traditional herbal medicine in East Asia such as Korea, China, and Japan. Especially, the leaves and the seeds of this species are important in Korean traditional cooking, as one of the popular garnish and food colorants. Numerous studies have revealed that the beneficial health effects of perilla are due to its several phytochemicals contents, such as rosmarinic acid, caffeic acid, luteolin, and apigenin. For this reason, increasing the content of phytochemicals in perilla hasbecome a major breeding objective. The genetic diversity of the rosmarinic acid, caffeic acid, luteolin, and apigenin content in perilla seed is poorly documented. We analyzed the rosmarinic acid, caffeic acid, luteolin, and apigenin content of 203 accessions of perilla germplasm by high performance liquid chromatography (HPLC). The rosmarinic acid and luteolin contents ofgermplasms were ranged from $15.7{\mu}g/g$ to $2717.1{\mu}g/g$ and from $1.6{\mu}g/g$ to $582.4{\mu}g/g$ respectively.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.875-888
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• 2018

Tulip (Tulipa L.) is one of the most important ornamental geophytes in the world. Analysis of molecular variability of tulips is of great importance in conservation and parental lines selection in breeding programs. Of the 70 genic microsatellites, 15 highly polymorphic and reproducible markers were used to assess the genetic diversity, structure, and relationships among 280 individuals of 36 wild and cultivated tulip accessions from two countries: Iran and the Netherlands. The mean values of gene diversity and polymorphism information content were 0.69 and 0.66, respectively, which indicated the high discriminatory power of markers. The calculated genetic diversity parameters were found to be the highest in wild T. systola Stapf (Derak region). Bayesian model-based STRU CTU RE analysis detected five gene pools for 36 germplasms which corresponded with morphological observations and traditional classifications. Based on analysis of molecular variance, to conserve wild genetic resources in some geographical locations, sampling should be performed from distant locations to achieve high diversity. The unweighted pair group method with arithmetic mean dendrogram and principal component analysis plot indicated that among wild tulips, T. systola and T. micheliana Hoog exhibited the closest relationships with cultivated tulips. Thus, it can be assumed that wild tulips from Iran and perhaps other Middle East countries played a role in the origin of T. gesneriana, which is likely a tulip species hybrid of unclear origin. In conclusion, due to the high genetic variability of wild tulips, they can be used in tulip breeding programs as a source of useful alleles related to resistance against stresses.

• Plant Breeding and Biotechnology
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• v.6 no.4
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• pp.321-336
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• 2018

Sesame (Sesamum indicum L.) is an important oilseed crop grown in tropical and subtropical areas. The objective of this study was to investigate the genetic relationships among 129 sesame landraces and cultivars using simple sequence repeat (SSR) markers. Out of 70 SSRs, 23 were found to be informative and produced 157 alleles. The number of alleles per locus ranged from 3 - 14, whereas polymorphic information content ranged from 0.33 - 0.86. A distance-based phylogenetic analysis revealed two major and six minor clusters. The population structure analysis using a Bayesian model-based program in STRUCTURE 2.3.4 divided 129 sesame accessions into three major populations (K = 3). Based on pairwise comparison estimates, Pop1 was observed to be genetically close to Pop2 with $F_{ST}$ value of 0.15, while Pop2 and Pop3 were genetically closest with $F_{ST}$ value of 0.08. Analysis of molecular variance revealed a high percentage of variability among individuals within populations (85.84%) than among the populations (14.16%). Similarly, a high variance was observed among the individuals within the country of origins (90.45%) than between the countries of origins. The grouping of genotypes in clusters was not related to their geographic origin indicating considerable gene flow among sesame genotypes across the selected geographic regions. The SSR markers used in the present study were able to distinguish closely linked sesame genotypes, thereby showing their usefulness in assessing the potentially important source of genetic variation. These markers can be used for future sesame varietal classification, conservation, and other breeding purposes.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.283-297
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• 2021

Investigation of genetic diversity and molecular characterization in high yielding rice varieties is important for their identification. The experiment was conducted during 2016 - 2017 to analyse the genetic diversity of fifteen high yielding rice varieties in Bangladesh by using random amplification of polymorphic DNA (RAPD) markers. Polymorphism was revealed in 12 RAPD primers out of 30, whereas no other reaction was detected on the remaining 18 primers. The 40 out of 45 bands (88.89%) polymorphics were produced by the primers and ranged from 50 to 100%. The maximum number of polymorphic bands was produced by the primer OPB-18 whereas the lowest number of polymorphic bands belonged to OPC-12. The genetic similarity coefficients were determined with the RAPD data, which ranged from 0.47 to 0.94. The unweighted paired group of arithmetic means (UPGMA) dendrogram presented the studied rice varieties into two major clusters. Moreover, the value of Nei's genetic diversity is 0.26 and the Shanon information index is 0.41. The study produced distinct positions, suggesting that the genotypes were different from each other. The results indicated that these markers could be efficient for comparing the genetic relationships, patterns of variation, and measurement of genetic distance among rice varieties. Considering all of these results, RAPD analysis is found to be an effective tool for estimating the genetic diversity of different rice varieties. The outcomes of this research may contribute to the germplasm data of rice accessions and a future breeding program of rice genotypes.

• Korean Journal of Plant Taxonomy
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• v.52 no.2
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• pp.102-107
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• 2022

Rhododendron keiskei var. hypoglaucum (Ericaceae) was recently reported in Korea, with a disjunct distribution on the southern islands of the Korean Peninsula. Although chromosome numbers and ploidy variations are important traits in angiosperms, gaining a clear understanding the cytological features of Rhododendron has been hampered by the small size of its chromosomes. We herein report the chromosome number, karyotype structure, and genome size of R. keiskei var. hypoglaucum for the first time. The chromosome number of the investigated plants was 2n = 26 with x = 13 as the base chromosome number, which is the one of the frequently encountered base chromosome numbers in Rhododendron. The karyotype of R. keiskei var. hypoglaucum is composed of metacentric and submetacentric chromosomes similar in length, which ranged from 1.39 to 2.40 ㎛. The DNA 1C-value in all examined accessions was small, ranging from 0.63 to 0.65 pg, further supporting the stable genome size in Rhododendron. These comprehensive cytological results provide a framework for detailed molecular, cytogenetic, and phylogenomic analyses that can be used to interpret the slow species diversification rate in Rhododendron.