• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.3
• /
• pp.251-255
• /
• 2004

The epidemics of rice blast which occurred in south parts of Korea during the period from 1999 to 2001 and damaged several high quality rice cultivars developed using "Milyang 95" and/or "Milyang 96" as a parent. Genetic diversity of 23 rice cultivars including "Milyang 95" and it's relatives was assessed using 54 simple sequence repeats (SSR) markers reported to be linked to major blast resistance genes. Fifty-four SSR markers representing fifty-seven loci in the rice genome detected polymorphism among the 23 cultivars and revealed a total of 170 alleles with an average of 3.0 alleles per primer, The number of amplified bands ranged from 1 to 7. Several SSR markers including RM249, RM206 and OSR20 were informative for assessing the genetic diversity of relatively closed japonica rice cultivars. The 23 cultivars were classified into four groups by cluster analysis based on Nei's genetic distances, and the cultivars developed from same parents showed a tendency to cluster together that is consistant with genealogical information. High quality rice cultivars, Daesanbyeo, Donganbyeo, and Milyang 95 belonged to the same cluster, At the loci, RM254 and OSR32, all of the cultivars derived from the crosses using "Milyang 95" shared same alleles, suggesting that these japonica cultivars might carry alleles that are identical by descent. Evaluation of 23 rice cultivars against blast needs to be confirmed regarding the relationship between genotype and blast resistance.p between genotype and blast resistance.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.56 no.4
• /
• pp.322-328
• /
• 2011

AFLP markers were employed to detect genetic diversity and genetic relationship among 26 accessions of foxtail millet collected from Korea. Analysis of 26 accessions of foxtail millet with nine AFLP primer set combinations detected a total of 170 bands, of which 145 (85.3%) showed polymorphic at the species level. The phenotypic diversity (Hs) calculated for the nine primer combinations ranged from 1.84 to 6.8, with an average of 3.85. The average phenotypic diversity values were 3.39 and 2.99 for accessions collected from Gangwon province (Group 1), and accessions collected from the other areas including Gyeonggi province (Group 2), respectively. In the cluster analysis of 26 accessions, two major groups were recognized at 73% genetic similarity. Group I includes 13 accessions, which were collected in Gangwon province, and 1 accession, which was collected in Gyeonggi province, with genetic similarity of 76.8%. Group II includes two accessions, which were collected in Gangwon province, and 10 accessions, which were collected in the other areas with genetic similarity of 78.9%. The presenting data on the assessment of genetic diversity and genetic relationships among Korean accessions of foxtail millet will be helpful for efficient collection or conservation strategy of foxtail millet germplasm in Korea.

• Journal of Environmental Policy
• /
• v.8 no.4
• /
• pp.1-24
• /
• 2009

As commercial use of genetic resources increases in modern society, calls for fair and equitable sharing of the benefits thereof have become increasingly prominent, particularly from developing countries. As a result, negotiations have been ongoing for the "International Regime on Access and Benefit Sharing (ABS)" for genetic resources as a successor to the non-binding Bonn Guideline. 2010 has been set as the target date for the Agreement. As South Korea is more likely to be a user country of genetic resources, it will be necessary for it to take part in the negotiating process and contribute to creating the International Regime on ABS, to ensure both appropriate access to genetic resources and fair and equitable sharing of the benefits arising there from. To develop appropriate response strategies for South Korea, it is critical not only to closely examine the negotiations within the framework of the CBD but also to engage in discussions within thescope of related international organizations and domestic legislation. To achieve this goal, it is imperative for South Korea to form a comprehensive Government Response System, composed of relevant governmental bodies including the Ministry of Foreign Affairs and Trade, and the Ministry of Environment, etc.

• Journal of Life Science
• /
• v.15 no.2 s.69
• /
• pp.273-278
• /
• 2005

Trifolium pratense (red clover, Fabaceae) is a short-lived herbaceous species and the species is introduced from Europe or North America to Korea approximately 60 years ago. Allozyme variability was examined in populations representing this species. A high level of genetic variation was found in T. pratense populations. Ten of 19 loci $(52.6\%)$ showed detectable polymorphism. Genetic diversity was 0.220. The sexual reproduction, high fecundity, and colonization process are proposed as possible factors contributing to high genetic diversity. Genetic diversity (0.220) was lower than that (0.285) of North American red clover, T. pratense. Korean populations of red clover may be founded by a small sample of larger or moderate populations. An indirect estimate of the number of migrants per generation (Nm = 4.20) indicated that gene flow was extensive among Korean populations of this species.

• Journal of Life Science
• /
• v.17 no.1 s.81
• /
• pp.24-30
• /
• 2007

Inter simple sequence repeat (ISSR) markers were performed in order to analyse the genetic relation-ships of both taxa of Gardenia jasminoides var. radicans and G. jasminoides for. grandifora. Over the 88 fragments, only one locus (ISSR-11-05) was specific to G. jasminoides var. radicans and only one (ISSR-09-05) G. jasminoides for. grandiflora. Although G. jasminoides var. radicans showed low levels of alleles and Shannon's information index than G. jasminoides for. Grandiflora, however, there was not significant differences (p > 0.05). For both taxa the mean genetic diversity of natural populations was higher than that of cultivation populations. It was suggested that domestication processes via artificial selection do not have eroded the high levels of genetic diversity. ISSR markers were more effective in classifying natural populations of wild G. jasminoides in East Asia as well as cultivated G. jasminoides. The information about the phylogenetic relationship of G. jasminoides var. radicans and its closely related species is very valuable of the systematics of genus Gardenia, the origin of cultivated G. jasminoides, and future G. jasminoides breeding.

• Korean Journal of Environment and Ecology
• /
• v.31 no.6
• /
• pp.492-499
• /
• 2017

This study analyzed 96 individuals in 6 populations using ISSR marker to investigate the genetic diversity of Salicornia herbacea populations. The total of 49 PCR amplification bands was observed in 6 ISSR primers, and 30 of them had genetic polymorphisms. The Shannon's information index (I) and gene diversity index (h), which indicate the genetic diversity of the Salicornia herbacea populations, were 0.382 and 0.249, respectively. The genetic diversity according to the population size was lowest with 0.092 (I) and 0.058 (h) in $0.1m{\times}0.1m$ and highest with 0.338 (I) and 0.227 (h) in $25m{\times}25m$, which was suitable for the furtherance of the high population with high genetic diversity. The UPGMA dendrogram based on Nei's genetic distance did not show a significant correlation with the distance between the Salicornia herbacea population. The results indicate that the Salicornia herbacea habiting in the restricted environment should have an area over a certain size to ensure the formation of a population with genetic diversity.

• Journal of Advanced Navigation Technology
• /
• v.18 no.2
• /
• pp.170-177
• /
• 2014

Genetic Algorithms are robust search and optimization techniques but have some problems such as premature convergence and convergence to local extremum. As population diversity converges to low value, the search ability decreases and converges to local extremum but population diversity converges to high value, then the search ability increases and converges to global optimum or genetic algorithm may diverge. To guarantee that genetic algorithms converge to the global optima, the genetic operators should be chosen properly. In this paper, we propose the genetic operators with the hybrid function of the average Hamming distance and the fitness value to maintain the diversity of the GA's population for escaping from the premature convergence. Results of simulation studies verified the effects of the mutation operator for maintaining diversity and the other operators for improving convergence properties as well as the feasibility of using proposed genetic operators on convergence properties to avoid premature convergence and convergence to local extremum.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.1
• /
• pp.119-130
• /
• 2014

This paper proposes GAPS, a practical genetic algorithm based pathfinding system for conveniently analyzing various networks. To this end, the GAPS is developed through integration of the intuitive graphic user interface for network modeling, the database management system for managing the data generated in modeling and exploring procedures, and a simple genetic algorithm for analyzing a wide range of networks. Especially, previous genetic algorithms are not appropriate for analyzing the networks with many dead-ends where there are few feasible paths between the given two nodes, however, GAPS is based on the genetic algorithm with the fitness function appropriate for evaluating both feasible and infeasible paths, which enables GAPS to analyze a wide range of networks while maintaining the diversity of the population. The experiment results reveal that GAPS can be used to analyze both networks with many dead-ends and networks with few dead-ends conveniently, and GAPS has several advantages over the previous genetic algorithms for pathfinding problems.

• Journal of Mushroom
• /
• v.18 no.4
• /
• pp.323-330
• /
• 2020

Agaricus bisporus is an important edible mushroom that is used as a functional food. In this study, European A. bisporus strains were analyzed for genetic diversity, population structure, and genetic differentiation using simple sequence repeat (SSR) markers. European A. bisporus strains were divided into four groups by distance-based analysis and two subpopulations by model-based analysis. The SSR markers used in this study did not group European A. bisporus strains by geographical region or pileus color. Genetic diversity was high in Group 4 based on distance-based analysis and Pop. 2 based on model-based analysis. A. bisporus strains showed very low genetic differentiation. The results of this study can be used for breeding A. bisporus in the future.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.5 no.4
• /
• pp.226-232
• /
• 2003

To examine the effects of ozone (O$_3$), one of the major air pollutants in the city area, on genetic changes in Cornus controversa Hemsl., we compared genetic structures between sensitive (S) and tolerant (T) tree groups of C. controversa fumigated with ozone using isozyme markers. The genetic structures were measured in terms of allele and genotype frequencies determined at ave polymorphic enzyme loci. Marked genetic differences between the two groups were detected at three loci (Lap-2, Mdh-1 and Skdh-1). Genetic parameters, genetic multiplicity, genetic diversity and heterozygosity showed that the tolerant group retained greater genetic variation than did the sensitive group. Results of the study were congruent with the general expectation that the more heterozygous individuals and/or populations exhibit higher resistance to various stress factors.