• 제목/요약/키워드: population biology

검색결과 1,535건 처리시간 0.065초

Population Dynamics of Five Anopheles Species of the Hyrcanus Group in Northern Gyeonggi-do, Korea

  • Jeong, Kyoung-Yong;Un, Sun-Jin;Lee, Jong-Weon;Lee, In-Yong;Yong, Tai-Soon;Ree, Han-Il
    • Parasites, Hosts and Diseases
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    • 제48권4호
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    • pp.351-353
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    • 2010
  • To investigate the population densities of potential malaria vectors, Anopheles species were collected by light traps in malaria endemic areas, Paju and Gimpo, Gyeonggi-do of Korea. Five Anopheles Hyrcanus sibling species (An. sinensis, An. pullus, An. lesteri, An. kleini, and An. belenrae) were identified by PCR. The predominant species, An. pullus was collected during the late spring and mid-summer, while higher population consists of An. sinensis were collected from late summer to early autumn. These 2 species accounted for 92.1 % of all Anopheles mosquitoes collected, while the other 3 species accounted for 7.9%. Taking into account of these population densities, late seasonal prevalence, and long-term incubation period (9-13 months) of the Korean Plasmodium vivax strain, An. sinensis s.s is thought to play an important role in the transmission of vivax malaria in the study areas.

Population genetic analysis of Salurnis marginella (Hemiptera: Flatidae)

  • Choi, Hyun-Seok;Jeong, Su Yeon;Lee, Keon Hee;Jeong, Jun Seong;Park, Jeong Sun;Jeong, Na Ra;Kim, Min Jee;Lee, Wonhoon;Kim, Iksoo
    • International Journal of Industrial Entomology and Biomaterials
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    • 제43권2호
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    • pp.67-77
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    • 2021
  • Salurnis marginella Guérin-Méneville, 1829 (Hemiptera: Flatidae) is an invasive species first reported in 2003 in Iksan, which is located in the mid-western region of South Korea, and subsequently found in the nearby regions in 2005. However, molecular-perspective reports on their invasive characteristics are not yet available. In this study, population genetic characteristics of Korean S. marginella were evaluated using the mitochondrial COI region and sequencing 124 individual samples collected in 11 Korean localities. A total of 12 haplotypes were identified with a maximum sequence divergence of 1.368% (9 bp). Haplotype diversity was relatively higher than that of other insect species invaded into Korea, providing 2-6 haplotypes per populations, indicating that introduction to Korea may have happened rather extensively and consistently. Nucleotide diversity (π) was the highest in Iksan but owing to the limited sample size (three individuals) from this locality, additional studies are required for drawing conclusive inference regarding the place of entry to Korea. Ulsan, the easternmost population in the present study, revealed nearly the lowest diversity estimates, such as the lowest H and the second-lowest π; a unique haplogroup with a higher frequency; and an independent genetic cluster, suggesting that the introduction of S. marginella to Ulsan was an independent event. Further collection in Korea and neighboring countries, including the original distributional range is necessary to elucidate the invasive dynamics of S. marginella

신갈나무 산림토양에서의 효소활성도 (Enzyme Activities in the Soil of Quercus mongolica Forests)

  • Song In-Geun;Yong-Keel Choi;Byung-Re Min
    • The Korean Journal of Ecology
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    • 제18권4호
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    • pp.503-512
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    • 1995
  • The present paper describes partial results of the study on the activities of microbes in the soil of Quercus mongolica forest from July, 1994 to April, 1995. To determine the relationship between structure and function of soil microbial ecosystem, the author investigated the seasonal change of physical environmental factors, microbial population and soil enzyme activities. The changes of pH was not significant and the temperature of surface soil was 2℃ higher than lower soil through out the year. Moisture contents (%) of soil samples ranged from 7.64% to 42.11%. However, soils of site 3 at Mt. Komdan in which vegetation is successional have higher moisture content than the others. The bacterial population increased in summer, but continuously decreased in autumn and winter, and then reincreased again in spring. Bacterial population of surface soil was higher than those of 30 cm depth all the year round. Dehydrogenase activity (DHA) was about two-fold higher throughout in surface soil compared to those of lower soil. And the correlation coefficient between DHA and bacterial population size was 0,713, It was suggested that DHA could be used as a primary index of soil microbial population and activity in soil ecosystem.

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Characteristics of Hypervariable Regions of Mitochondrial DNA in Korean Population

  • Han, Jae-Seok;Lee, Dong-Hoon;Rho, Hyune-Mo
    • BMB Reports
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    • 제31권6호
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    • pp.604-606
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    • 1998
  • The nucleotide sequence of two hypervariable regions of the D-loop and the frequency of the 9-bp repeat in the region V of mitochondrial DNA (mtDNA) were investigated in the Korean population. Alignment of these sequences with the published reference revealed a unique pattern of base substitution and deletion compared with those of other races. The deletion and addition frequency of the 9-bp repeat in the region V was also distinct.

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Genetic Variation and Population Structure of Crepidiastrum lanceolatum (Compositae)

  • Huh, Man-Kyu;Choi, Joo-Soo
    • Journal of Life Science
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    • 제12권1호
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    • pp.9-13
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    • 2002
  • Crepidiastrum lanceolatum ($H_{OUTT}$) $N_{AKAI}$ (Compositae) is distributed in East Asia including Korea. Genetic diversity and population structure of six C. lanceolatum populations in Korea and two populations in Japan were determined using genetic variation at 19 allozyme loci. The percent of polymorphic loci within the enzymes was 42.1%. Genetic diversity at the species level and at the population level was low (Hes : 0.077; Hep : 0.068, respectively), where-as the extent of the population divergence was relatively low ($G_{ST}$ : 0.093). One of the most striking features of this study was the more significant difference within populations than among populations. An indirect estimate of the number of migrants per generation (Nm : 2.44) indicated that gene flow was moderate among eight populations of the species. In addition, analysis of fixation indices revealed a slight heterozygosity deficiency in some populations and at some loci. Narrow geographic ranges, short-lived perennial herbaceous, and small population sizes are mainly associated with the low level of genetic variation.n.

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