• Journal of Plant Biotechnology
• /
• v.44 no.3
• /
• pp.312-319
• /
• 2017

The need to preserve and use plant genetic resources is widely recognized, and the prospect of dwindling plant genetic diversity, coupled with increased demands on these resources, has made them a topic of global discussion. In the present study, the genetic diversity and population structure of 73 ginseng accessions collected from six regions in China were analyzed using eight simple sequence repeat (SSR) markers. Major allele frequencies ranged between 0.38 ~ 0.78, with a mean allele frequency value of 0.571. The number of alleles discovered ranged from 3 to 10 per accession, with a mean number of 7; 56 alleles were discovered in total. Gene diversity (GD) and polymorphic information content (PIC) values were similar to each other, and they ranged from 0.36 ~ 0.77 (mean 0.588) and 0.33 ~ 0.74 (mean 0.548), respectively. Accessions were divided into three clusters based on their phylogenetic relationships and genetic similarities, and although the populations were similar, they were not classified according to the region. Regional genetic diversity was also similar, with slight differences observed based on the number of accessions per region. It is expected that the findings of the present study can provide basic data for future studies on ginseng genetic diversity and for breeding ginseng cultivars.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.47 no.2
• /
• pp.99-114
• /
• 2023

Patanga japonica Bolívar, 1898 (Orthoptera: Acrididae) is listed as a climate-sensitive indicator species in South Korea and is called southern group of insects in that the main distributional range is southern region of South Korea and Asian continent. In South Korea, thus, the species was distributed mainly in southern region of South Korea including southward a remote Jeju Island, but recently the species has often been detected in mid to northern region of South Korea, implying northward range expansion in response to climate change. Understanding the characteristics of the changes in genetic diversity during range expansion in response to climate change could be a foundation for the understanding of future biodiversity. Thus, in this study, we attempted to understand the changing pattern of the genetic diversity of the P. japonica in newly expanded regions. For the purpose of study, we collected 125 individuals from seven localities throughout South Korea including two newly distributed regions (Pyeongtaek and Yeongwol at ~37° N). These were sequenced for a segment of mitochondrial cytochrome oxidase subunit I (COI) and analyzed for genetic diversity, haplotype frequency, and population genetic structure among populations. Interestingly, northward range expansion accompanied only haplotypes, which are most abundant in the core populations, providing a significant reduction in haplotype diversity, compared to other populations. Moreover, genetic diversity was still lower in the expanded regions, but no genetic isolation was detected. These results suggest that further longer time would take to reach to the comparable genetic diversity of preexisting populations in the expanded regions. Probably, availability of qualified habitats at the newly expanded region could be pivotal for successful northward range expansion in response to climate change.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.6
• /
• pp.776-783
• /
• 2008

In this study, we investigated the genetic diversity and phylogenetic relationship of six duck populations by employing the genetic polymorphisms of 20 microsatellites. The parameters used in this study included number of alleles, average effective numbers of alleles (E) and average rates of heterozygosity of each population. The results showed that all the microsatellite loci were highly polymorphic except that the locus AJ515896 in Muscovy duck was 0. The average PIC (0.762), average h (0.7843) and average E (5.261) of the six duck populations were all high, indicating that the gene polymorphisms and genetic diversity were high. The test of Hardy-Weinberg equilibrium showed that the six populations in this study were all in Hardy-Weinberg disequilibrium. The F-statistic analysis results showed the range of FST was from 0.0205 (AJ515895) to 0.2558 (AJ515896). The mean FST was 0.0936. Phylogenetic study revealed that Peking duck (Z1 and Z4), Shaoxing duck, Cherry Valley duck and Aobaixing duck were clustered in one group, while the Muscovy duck was clustered in one group alone. The phylogenetic relationships among different populations were in accordance with their breeding history and distribution. Our data suggested that the 20 microsatellite loci were effective markers for analysis of genetic relationships among duck populations.

• Korean Journal of Medicinal Crop Science
• /
• v.13 no.2
• /
• pp.69-74
• /
• 2005

Kalopanax pictus is a long-lived woody species mostly distributed in East Asia. K. pictus has been regarded as medically and ecologically important species in Korea. Thornless castor aralia variant, local name 'Cheongsong' is an endemic to Cheongsong province in Korea. Random amplified polymorphic DNA (RAPD) was used to investigate the genetic variation and structure of Korean populations of two species. A high level of genetic variation was found in six K. pictus populations. Twelve primers revealed 49 loci, of which 29 were polymorphic (59.2%). Nei's gene diversity for K.pictus and K. pictus variant were 0.119 and 0.098, respectively. Mean of genetic diversity in K. pictus was higher than average values for species with similar life history traits. The asexual and sexual reproduction, perennial habitat, and longevity are proposed as possible factors contributing to high genetic diversity. An indirect estimate of the number of migrants per generation (Nm=0.857) indicated that gene flow was not extensive among Korean populations of K.pictus. It is suggested that the isolation of geographical distance and reproductive isolation between K.pictus and K.pictus variant populations may have played roles in shaping the population structure of this species.

• Environmental Engineering Research
• /
• v.24 no.2
• /
• pp.181-190
• /
• 2019

Constructed wetlands are improvised man-made systems, designed for adopting the principle of natural wetlands for purifying wastewater - the elixir of life. They are used widely as a cost-effective and energy-efficient solution for treating greywater generated from different tertiary treatment sources. It provides an elaborate platform for research activities in an attempt to recycle earth's natural resources. Among the several organic impurities removal mechanisms existing in constructed wetland systems, the earth's active microbial population plays a vital role. This review deals with the recent advancements in constructed wetland systems from a microbiological perspective to (effect/ devise/ formulate) chemical and physical treatment for water impurities. It focuses on microbial diversity studies in constructed wetlands, influence of wetland media on microbial diversity and wetland performance, role of specific microbes in water reuse, removal of trace elements, some heavy metals and antibiotics in constructed wetlands. The impurities removal processes in constructed wetlands is achieved by combined interactive systems such as selected plant species, nature of substrate used for microbial diversity and several biogeochemical effected reaction cycles in wetland systems. Therefore, the correlation studies that have been conducted by earlier researchers in microbial diversity in wetlands are addressed herewith.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.04a
• /
• pp.110-110
• /
• 2022

Rice is the world's most important food crop and a major source of nutrition for about two thirds of populations. Northern Vietnam is one of the most important centers of genetic diversity for cultivated rice. In this study, we determined the genetic diversity and population structure of 79 rice landraces collected from northern Vietnam and 19 rice accessions collected from different countries. In total, 98 rice accessions could be differentiated into japonica and indica with moderate genetic diversity and a polymorphism information content of 0.382. We also detected subspecies-specific markers to classify rice (Oryza sativa L.) into indica and japonica. Additionally, we detected five marker-trait associations and rare alleles that can be applied in future breeding programs. Most interestingly, analysis of molecular variance (AMOVA) found genetic differentiation was related to geographical regions with an overall PhiPT (analog of fixation index FST) value of 0.130. More emphasis was given to provide signatures and infer explanations about the role of geographical isolation and environmental heterogeneity in genetic differentiation among regions in landraces from northern Vietnam. Our results suggest that rice landraces in northern Vietnam have a dynamic genetic system that can create different levels of genetic differentiation among regions, but also maintain a balanced genetic diversity between regions.

• Animal Bioscience
• /
• v.37 no.5
• /
• pp.795-806
• /
• 2024

Objective: Karan Fries (KF), a high-producing composite cattle was developed through crossing indicine Tharparkar cows with taurine bulls (Holstein Friesian, Brown Swiss, and Jersey), to increase the milk yield across India. This composite cattle population must maintain sufficient genetic diversity for long-term development and breed improvement in the coming years. The level of linkage disequilibrium (LD) measures the influence of population genetic forces on the genomic structure and provides insights into the evolutionary history of populations, while the decay of LD is important in understanding the limits of genome-wide association studies for a population. Effective population size (N_e) which is genomically based on LD accumulated over the course of previous generations, is a valuable tool for e valuation of the genetic diversity and level of inbreeding. The present study was undertaken to understand KF population dynamics through the estimation of N_e and LD for the long-term sustainability of these breeds. Methods: The present study included 96 KF samples genotyped using Illumina HDBovine array to estimate the effective population and examine the LD pattern. The genotype data were also obtained for other crossbreds (Santa Gertrudis, Brangus, and Beefmaster) and Holstein Friesian cattle for comparison purposes. Results: The average LD between single nucleotide polymorphisms (SNPs) was r² = 0.13 in the present study. LD decay (r² = 0.2) was observed at 40 kb inter-marker distance, indicating a panel with 62,765 SNPs was sufficient for genomic breeding value estimation in KF cattle. The pedigree-based N_e of KF was determined to be 78, while the N_e estimates obtained using LD-based methods were 52 (SNeP) and 219 (genetic optimization for N_e estimation), respectively. Conclusion: KF cattle have an N_e exceeding the FAO's minimum recommended level of 50, which was desirable. The study also revealed significant population dynamics of KF cattle and increased our understanding of devising suitable breeding strategies for long-term sustainable development.

• Journal of Korean Society of Forest Science
• /
• v.96 no.6
• /
• pp.667-675
• /
• 2007

The genetic diversity and the spatial structure in two populations of Abelia tyaihyoni in Yeongwol region were studied by employing I-SSR markers. In spite of the limited distribution and small population sizes of Abelia tyaihyoni, the amount of genetic diversity estimated at the individual level was comparable to other shrub species (S.I.=0.336, h=0.217). Genetic diversity at the genet level was very similar to that at individual level. (S.l.=0.339, h=0.219). About 18.7 percent of total variation was allocated between two populations, which was slightly higher or similar level as compared with other shrub species. Genotypic diversity estimated by the ratio of the number of genets ($N_G$) over the total number of individuals (N) and a modified Simpson's index ($D_G$) were also higher than those of other shrubs. The maximum diameter of a genet did not exceed 5.5 m. The high level of gene and genotypic diversity, and the relatively limited maximum diameter of a genet suggested that the clonal propagation is not the most dominant factor in determining the population structure of Abelia tyaihyoni. Spatial autocorrelation analysis revealed significant spatial genetic structure within 12 m and 18 m distances in two populations A and B, respectively. Autocorrelations among individuals at the both individual and genet levels in each population didn't show any considerable differences. As a sampling strategy for ex-situ conservation of populations showing continuous distribution, a minimum distance of 18 m between individuals was recommended. For the populations with many segments, it was considered very crucial to sample materials from as many segments as possible.

• Journal of Korean Society of Rural Planning
• /
• v.28 no.3
• /
• pp.73-82
• /
• 2022

Recently, social conflicts have intensified, and a diverse society is to the fore as a solution to social problems. In rural areas, the transition to a diverse society progressed due to population outflow, changes in the agricultural labor force, and an increase in multicultural families. In this study, regional social diversity in Gyeongsangnam province was measured using the neighborhood diversity index and the Simpson index. In addition, the relationship with the regional economy at the county level and township level was analyzed. As a result, it was found that the Gun regions have higher social diversity than the Si regions. and the city area showed a larger index value for residential segregation.

• Proceedings of the Botanical Society of Korea Conference
• /
• 2001.04a
• /
• pp.18-18
• /
• 2001