• Title/Summary/Keyword: mating populations

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Marker-Assisted Mating Applied in In-Situ Conservation of Indigenous Animals in Small Populations : (1) Choosing Mating Schemes for Maximum Heterozygosity

  • Wu, X.L.;Liu, R.Z.;Shi, Q.S.;Liu, X.C.;Li, X.;Wu, M.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.4
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    • pp.431-434
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    • 2000
  • Maintaining maximum genetic variability is of critical importance with in-situ conservation of animal species in small populations. Marker-assisted mating (MAM) was suggested to achieve maximum heterozygosity in offspring populations. The aims of this research was to investigate and decide the effectiveness and promising types of MAM to achieve this goal. Analysis of variance with simulation data revealed that the heterozygosity in offspring populations was significantly determined by sire heterozygosity from mating of non-inbred parent animals, and significantly by sire heterozygosity and percent parental difference in offspring reproduced by inbred parents. Seven types of marker-assisted mating schemes were examined, in which offspring exhibited heterozygosity that was -0.01 to 7.37% below or above that from random mating of non-inbred parent animals, and 0.00 to 16.39% above that from random mating of inbred parent animals. The great increase in offspring heterozygosity was observed with mating by tandem maximizing sire heterozygosity, percent parental difference, and dam heterozygosity. Random mating resulted in fluctuation of offspring heterozygosity. These results suggested that MAM was a promising method for maintaining maximum offspring variability in in-situ conservation of animal species in small populations.

Comparison of Mating Systems in Populations of Gleditsia japonica var. koraiensis

  • Huh, Man-Kyu
    • Journal of Ecology and Environment
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    • v.29 no.5
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    • pp.411-414
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    • 2006
  • The mating systems of two groups of natural populations of Gleditsia japonica var. koraiensis in Korea were determined using allozyme analysis. The result suggests that G. japonica var. koraiensis is predominantly outcrossing. The tm values of eight populations in Korea varied from 0.667 (Mdh-1) to 0.938 (ldh-1), giving an average 0.820. Population and individual outcrossing estimates were associated with flowering tree density or degree of spatial isolation. The reason for relatively low outcrossing rates of some populations could be attributed to reduction of effective population sizes of sib for the medicine, small population size, and isolation of flowering mature trees. The heterozygote excesses were observed in some natural populations, whereas other populations exhibited varying degrees of inbreeding and heterozygotes deficit. Thus, selection against homozygotes operated in the progeny populations throughout the life cycle.

Mating Systems and Inbreeding Pressure in Populations of Wild Lentil Tare, Vicia tetrasperm (Leguminosae) (얼치기완두(콩과) 집단의 교배계와 내교잡 압력)

  • Huh, Man-Kyu
    • Journal of Life Science
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    • v.17 no.11
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    • pp.1477-1481
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    • 2007
  • The mating systems of natural populations of Vicia tetrasperm in Korea were determined using allozyme analysis. The result suggests that V. tetrasperm is low rates of outcrossing or mix-mating outcrossing (self-fertilization, s < 0.5). At the population levels, the values of inbreeding coefficient of ten populations in Korea varied from 0.131 to 0.176, giving an average 0.154. For ten natural populations, multi-locus estimates of outcrossing (tm) was 0.333 across fifteen polymorphic loci, with individual population values ranging from 0.269 to 0.423. The differences between the tm and ts values were not close to zero (tm - ts > 0.154), indicating that biparental inbreeding was significant in the loci. The reason for relatively low outcrossing rates of some populations could be attributed to extensive consanguineous mating and isolation of flowering mature plants. Although heterozygote excess was observed in one natural population, most populations exhibited varying degrees of inbreeding and heterozygotes deficit. Thus, selection against homozygotes operated in the progeny populations throughout the life cycle.

Mating Behavior, Mycotoxin Production, and Vegetative Compatibility of Gibberella fujikuroi Species Complex from Sorghum in Korea

  • Lim, Sun-Hee;Yun, Sung-Hwan;Lee, Yin-Won
    • The Plant Pathology Journal
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    • v.17 no.5
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    • pp.276-280
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    • 2001
  • Fusarium isolates of Gibberella fujikuroi species complex were obtained from sorghum grown in five provinces of Korea in 1996 and 1997. These isolates were characterized based on their mating behavior, mycotoxin production, and vegetative compatibility. Only three mating populations (A, D, and F) were recovered from a total of 155 isolates examined. The relative frequency of the mating populations was significantly different: F was predominant (80%), while D and A were observed at low frequencies of 9% and 3%, respectively. Female fertile isolates were more common within F (44 our of 124) than D (2 out of 14), while none of the five A isolates were female fertile. The inbreeding effective population sizes ($\textrm{N}_e$)for mating type and male/hermaphrodite ratios in mating populations A and D produced significant amounts of fumonisins, while F isolates produced none or only traces of fumonisin B$_1$. In contrast. F isolates produced higher amounts of moniliformin (average of 3,820 ppm) than A and D isolates (averages of 77 and 1,819 ppm, respectively). Fifty-one isolates were tested for vegetative compatibility using nitrogen non-utilization mutants of each isolate, and 44 vegetative compatibility groups (VCGs) were identified. A single VC type (VC1) was found in all of the five A isolates examined. Six of the D isolates examined consisted of three VC types: two for VC2, two for VC3, and the rest for VC4. All of the F isolates tested were incompatible in every combination and , thus, each constituted a unique VCG.

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Comparison of Reproductive Modes in Populations of Potentilla freyniana

  • Huh, Man-Kyu
    • Journal of Ecology and Environment
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    • v.30 no.3
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    • pp.225-229
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    • 2007
  • The mating systems of natural populations of Potentilla freyniana in Korea were determined using allozyme analysis. The result suggests that P. freyniana is outcrossing as well as employing vegetative reproduction by stolon (self-fertilization rate, s < 0.5). The values of the inbreeding coefficient of eight populations in Korea varied from 0.244 to 0.331, with an average value of 0.274. For eight natural populations, multi-locus estimates of outcrossing (tm) was 0.603 across 13 polymorphic loci, with individual population values ranging from 0.530 to 0.652. The relatively low outcrossing rates of some populations could be attributed to extensive vegetative reproduction by stolon and the isolation of flowering mature plants. Although P. freyniana usually propagated by asexually-produced ramets, I could not rule out the possibility that sexual reproduction occurred at a low rate because each ramet may produce terminal flowers. Although heterozygote excess was observed in some natural populations, most populations exhibited varying degrees of inbreeding and a heterozygote deficit.

Mating behavior of the Mongolian racerunner (Eremias argus; Lacertidae, Reptilia)

  • Kim, Bin-Na;Kim, Ja-Kyeong;Park, Dae-Sik
    • Animal cells and systems
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    • v.16 no.4
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    • pp.337-342
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    • 2012
  • Information about the mating behaviors of an endangered species is critical for the understanding of the natural history of the species as well as in situ and ex situ breeding programs designed to rehabilitate field populations. We describe the mating behaviors of the Mongolian racerunner (Eremias argus), an endangered species in South Korea. The mating of this species consists of precopulatory, copulatory, and postcopulatory stages and is composed of 12 different mating behaviors. During the postcopulatory stage, other males or females not involved in mating show more interference behaviors than during the precopulatory and copulatory stages. The male E. argus has an extraordinarily long postcopulatory bite, which may function as a type of mate-guarding behavior. This study is the first report on the mating behavior of a South Korean reptile.

Gene Flow of Oriental Fruit Moth, Grapholita molesta, Populations Analyzed by RAPD Molecular Markers (RAPD 분자지표를 이용한 복숭아순나방(Grapholita molesta)의 집단 유전적 변동 분석)

  • Son, Ye-Rim;Kim, Yong-Gyun
    • Korean journal of applied entomology
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    • v.47 no.1
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    • pp.37-44
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    • 2008
  • Oriental fruit moth, Grapholita molesta, is a serious pest on apples. To control this pest in an environmentally friendly method, mating disruption strategy using sex pheromone has been developed. Area-wide application of mating disruption has been needed to be effective, with little understanding on how much size of apple cultivating area should be treated in one time application of the mating disruption technique. On this matter, we needed to determine a minimal mating active zone of G. molesta that should be applied with mating disrupters to be effective. Molecular markers to discriminate a specific population should be developed to trace population migration for reproductive behaviors. Here we developed two effective molecular markers using random amplified polymorphic DNA (RAPD) technique. Different field populations of G. molesta, based on locations and seasons, were analyzed with these markers. In a specific location, G. molesta populations varied in genetic composition with different seasons. Different local populations showed differential variation according to their relative distances among apple orchards. In overall, genetic variation among different populations became lessen with progression of seasons.

Differential Growth Response of $A_1\;and\;A_2$ Mating Types of Phytophthora infestans on Rye A and V-8 Juice Agar Media Supplemented with Rhizome Powder of Cyperus rotundus

  • Singh, U.P.;Sarma, B.K.;Nishimura, Ruo;Kobayashi, Kiroku;Ogoshi, Akira;Zinkernagel, Volker;Schlenzig, Alexendra;Schober-Butin, Barbel;Aust, H.J.
    • Mycobiology
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    • v.29 no.3
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    • pp.164-169
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    • 2001
  • A new medium for studies of diversity among populations of $A_1\;and\;A_2$ mating types of Phytophthora infestans has been evolved. The rye A agar and V-8 juice agar media on which P. infestans grows well have been amended with rhizome powder of Cyperus rotundus. A total of 259 isolates of $A_1\;and\;A_2$ mating types representing Japan, Korea, India, Taiwan, Indonesia, Thailand, China, Nepal, U.K and Medico were screened for their growth response on these two media. Most of the A1 isolates did not grow well on them except Thailand while growth of $A_2$ mating types differed as some grew on it whereas others did not. It is quite likely that the populations of $A_2$ mating types that did not grow well on rhizome-amended medium are of different clonal lineage. This suggests that this medium can be used for the study of diversification among the isolates of the same or both the mating types as well as to detect the newly introduced genetically different isolates of P. infestans in a locality where it was not reported earlier.

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A Preliminary Population Genetic Study of an Overlooked Endemic ash, Fraxinus chiisanensis in Korea Using Allozyme Variation

  • Lee, Heung Soo;Chang, Chin-Sung;Kim, Hui;Choi, Do Yeol
    • Journal of Korean Society of Forest Science
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    • v.98 no.5
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    • pp.531-538
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    • 2009
  • We used enzyme electrophoresis to evaluate genetic diversity in five populations of endemic ash, Fraxinus chiisanensis in Korea. Of 15 putative allozyme loci examined 26.7% were polymorphic and expected heterozygosity for the species was low (0.082). Within the range, population were highly differentiated ($F_{ST}$=0.356) and little genetic variation was explained by geography. The pattern of distribution of variation showed low genetic variation within populations and pronounced divergence among populations, which was consistent with the prediction for the effects of limited gene flow and local genetic erosion. Although the frequencies of male plants were dominant ranging from 79.3% to 89.4%, most mating events seems to be inevitable mating between relatives in small populations based on heterozygote deficiency of this species. Small effective population size and the limited dispersal contributed to the low rates of gene flow within as well as between populations.

Efficacy of Commercial Mating Disruptors on Field Overwintering Populations of Oriental Fruit Moth, Grapholita molests (Busck) (야외 월동세대 복숭아순나방(Grapholita molesta (Busck))에 대한 교미교란제의 효과)

  • Jung, Sung-Chae;Park, Chun-Woo;Park, Man-Woong;Lee, Soon-Won;Choi, Kyung-Hee;Hong, Yong-Pyo;Kim, Yong-Gyun
    • Korean journal of applied entomology
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    • v.45 no.2 s.143
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    • pp.235-240
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    • 2006
  • Efficacies of two commercial mating distruptor (SPLAT$^{(R)}$ and Isomate$^{(R)}$-ROSSO) were evaluated on field overwintering populations of Oriental fruit moth, Grapholita molesta (Busck), in four apple orchards. Based on the monitoring with sex pheromone traps, all the orchards (Youngchun, Kyungsan, Chungsong, and Youngju in Korea) exhibited significant overwintering populations from late April to late May. Both mating disruptors that were applied 10 days before the monitoring period significantly inhibited the male orientation to the monitoring lures, in which SPLAT type was more effective than Isomate type in the disrupting efficacy. The disruption of male orientation was highly correlated with the reduction in the early leaf damage caused mostly by G. molesta.