• Korean journal of applied entomology
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• v.43 no.1
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• pp.43-48
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• 2004

Development of 3,700 folds resistance to etoxazole was found in the population of twospotted spider mite, Tetranychus urticae, collected from rose greenhouses in Buyo, Chungnam Provience in August 2000. This population was selected for 3yr with etoxazole to get 5,000,000 folds increase in resistance as compared to susceptible (S) strain. The etoxazole resistance was stablized for 16 months under the condition of no acaricide application. Inheritance and cross resistance in etoxazole to some acaricides of the etoxazole resistance strain (R) were investigated. There were differences of susceptibility in the etoxazole concentration-mortality relationships between $F_1$, $F_2$ progenies obtained from reciprocal cross with the S and R strains (R$_{♂}$${\times}$S$_{♂}$${\times}$R$_{♂}$). Degrees of dominance were 0.98 and 0.98 in $F_1$ and $F_2$ progenies of R$_{♂}$${\times}$S$_{♂}$, and -0.97 and -0.68 in $F_1$ and $F_2$ progenies of S$_{♀}$${\times}$R$_{♂}$ respectively. Inheritance in $F_1$ and $F_2$ progenies of R$_{♀}$${\times}$S$_{♂}$ were complete dominant. However $F_1$ and $F_2$ progenies of S$_{♀}$${\times}$R$_{♂}$ were incomplete recessive. These results suggest that inheritance of etoxazole resistance is controlled by a complete dominance. The R strain exhibited cross resistance to acequinocyl and emamectin benzoates in adult females, and milbemectin, amitraz and pyridaben in eggs. However they showed negatively correlated cross-resistance to bifenazate, a carbazate acaricide. These results may indicate bifenazate could be useful for the control of etoxazole resistant T. urticae population.

• Korean Journal of Breeding Science
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• v.43 no.2
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• pp.120-125
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• 2011

A field experiment was conducted to examine the fruit quality characters in second generation ($F_2$) hybrid cultivar and to compare the fruit characters with original $F_1$ hybrid cultivar of minipaprika (yellow and orange type) at the Research Farm, Hwacheon in July, 2010. Fruit characters varied within $F_2$ population of each minipaprika type. In minipaprika yellow, fruit weight varied from 12.2 g to 50.8 g (average 28.5 g) and fruit length/width varied from 1.4 to 2.8 (average, 2.0). Pericarp thickness ranged from 1.8 mm to 4.1 mm (average, 2.9 mm). Total soluble solid (TSS) varied from $6.2^{\circ}Brix$ to $13.5^{\circ}Brix$ with an average of $8.7^{\circ}Brix$. Fruit volume varied from 10.3 cc to 46.7 cc with an average of 24.4 cc. In minipaprika orange type, fruit weight ranged from 19.7 g to 42.4 g (average, 29.0 g) and fruit length/width varied from 1.5 to 2.6 (average, 2.0). Pericarp thickness varied from 2.1 mm to 4.1 mm with an average of 3.0 mm. TSS varied from $5.0^{\circ}Brix$ to $12.2^{\circ}Brix$ (average, $7.9^{\circ}Brix$) and average fruit volume was 24.6 cc ranging from 10.7 cc to 35.0 cc. The average fruit quality characters in $F_2$ population in both yellow and orange minipaprika did not differ from their $F_1$ hybrid parent and $F_2$ seed can be an additional way to supply high yielding hybrid cultivars at lower cost to the minipaprika growers.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.470-474
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• 1998

Data on the first lactation performance traits of $F_1$, $F_2$ and $F_3$ crosses covering the period from 1972 to 1995 of a total of 803 dairy cows of three genetic grades maintained at Livestock Production Research Farm, Indian Veterinary Research Institute, Izatnagar were analysed. Three genetic grades were 1/2 Friesian + 1/2 Hariana (FH), 1/2 Friesian + 1/4 Brown Swiss and 1/4 Hariana (FBH) and 1/2 Friesian+ 1/4 Jersey + 1/4 Hariana (FJH). Age at first calving increased by 7% and 8% in $F_2$ and $F_3$, respectively, over the $F_1$ in FH. The reduction in age at first calving at $F_2$ and $F_3$ levels by 2-7% over the $F_1$ was observed in FBH and FJH. The lactation milk yield of $F_1$, $F_2$ and $F_3$ crosses was $1,943{\pm}100.3$, $2202{\pm}120.5$ and $1,925{\pm}123.2kg$ in FH; $2,014{\pm}76.7$, $2,264{\pm}91.5$ and $2,096{\pm}123.9kg$ in FBH and $2,005{\pm}87.0$, $2,414{\pm}94.4$ and $2,093{\pm}121.1kg$ in FJH, respectively. The lactation milk yield improved by 12-20% in $F_2$ crosses in various genetic grades. The performance of $F_1$ was, however, maintained in FH $F_3$ crosses, it improved by 4% in FBH and FJH $F_3$ crosses. The lactation lengths and calving intervals were nearly the same for $F_1$, $F_2$ and $F_3$ crosses in FH while lactation lengths and calving intervals were reduced by 3-11% in $F_2$ and $F_3$ crosses in FBH and FJH genetic grades. The milk yield/day of lactation length and milk yield/day of calving interval increased by 16-35% in $F_2$ and 2-14% in $F_3$ over the $F_1$ in various genetic grades. It is recommended that a sufficiently large effective population size of these three genetic grades be maintained by inter se matings and rigorous selection of sires so for developing a genetic base population for new breed development.

• Animal Bioscience
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• v.34 no.7
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• pp.1116-1122
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• 2021

Objective: The aim was to characterize the genetic diversity evolution of the registered Mexican Charolais cattle population by pedigree analysis. Methods: Data consisted of 331,390 pedigree records of animals born from 1934 to 2018. Average complete generation equivalent, generation interval, effective population size (N_e), and effective numbers of founders (f_e), ancestors (f_a), and founder genomes (N_g) were calculated for seven five-year periods. The inbreeding coefficient was calculated per year of birth, from 1984 to 2018, whereas the gene contribution of the most influential ancestors was calculated for the latter period. Results: Average complete generation equivalent consistently increased across periods, from 4.76, for the first period (1984 through 1988), to 7.86, for the last period (2014 through 2018). The inbreeding coefficient showed a relative steadiness across the last seventeen years, oscillating from 0.0110 to 0.0145. During the last period, the average generation interval for the father-offspring pathways was nearly 1 yr. longer than that of the mother-offspring pathways. The effective population size increased steadily since 1984 (105.0) and until 2013 (237.1), but showed a minor decline from 2013 to 2018 (233.2). The population displayed an increase in the f_a since 1984 and until 2008; however, showed a small decrease during the last decade. The effective number of founder genomes increased from 1984 to 2003, but revealed loss of genetic variability during the last fifteen years (from 136.4 to 127.7). The f_a:f_e ratio suggests that the genetic diversity loss was partially caused by formation of genetic bottlenecks in the pedigree; in addition, the N_g:f_a ratio indicates loss of founder alleles due to genetic drift. The most influential ancestor explained 1.8% of the total genetic variability in the progeny born from 2014 to 2018. Conclusion: Inbreeding, N_e, f_a, and N_g are rather beyond critical levels; therefore, the current genetic status of the population is not at risk.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.9-15
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• 2009

Recently, giant embryonic rice and functional rice food are preferred by more consumers, which are attributed to the fact that the embryo has high concentrations of essential amino acids, fatty acids, and vitamins relative to other parts of rice grains. In this report, the heredity and stability of giant embryo mutations in successive generations were analyzed regarding a giant embryonic line, 'P47', induced by T-DNA insertion and a $F_2$ population from a cross between 'P47' and 'Junam'. The mutant lines with increases of 1.5, 1.7 and 1.8 times on embryo length, width and 100-embryo weight to those of the control showed stable inheritance across three generations. The continuous frequency distributions of embryo size in the $F_2$ population showed that the embryo size is a quantitative trait of polygene controlled. In addition, wide range of transgressive segregations of six traits affecting embryo size confirmed exchange of genetic materials and recombination between genes controlling embryo size. Five giant embryo mutant lines selected from the $F_2$ population will be used for artificial selection and improvement of giant embryonic varieties.

• Korean journal of applied entomology
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• v.18 no.4 s.41
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• pp.153-160
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• 1979

The present experiments were carried out to reduce the population density of adult pine gall midge, Thecodiplosis japonensi,s UCHIDA et INOUYE, by means of spray the sticky agent C-4, on the ground, herbacious plantation and foliar leaf of pine trees at Sanbonli,. Anyang, Kyungido. And also the 3 periods of treatment, such as before 2 weeks( I ), before 1 week (II) from the peak emergence period and peak emergence period (III) were applied. The experimental results obtained were as follows. (1) The formula of selected sticky agent C-4 was $70\%$ of castor oil, $25\%$ of damar resin and $5\%$ of carnauba wax, and it showed the best both on stickiness and duration, and lower phytotoxicity to the host plant. (2) The reduction of population densities of the adult PGM were $68\%$ and 78f: in the G-I and G-II treatment plot respectively, which compared to control, on the ground spray. (3) And the reduction of population densities were $63\%$ and about $90\%$ in the P-I and P-II plot respectively when the agent was sprayed on the herbacious plantation. (4) The rates of gall formation were $32.8\%,\;40.8\%\;and\;59.4\%$ in the spray plots of F-I, F-II, and F-III respectively, and there was no significant difference among the upper, middle and lower parts of the treated host plant in the rates of gall formation. (5) The effective stage of sticky agent application were considered as before one week from the peak emergence period in tile all types of treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.51-54
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• 2007

Soybean has a morphological type with a broadened and flattened stem. Fasciation has been suggested as a new gene for soybean research. SSR marker linked to the $\Large f$ locus that controls fasciation phenotype has not identified within 10 cM. A mapping population consisting of 94 $F_2$ progenies was derived from a cross between wild type Clark (FF) and fasciation mutant C32 (${\Large f}{\Large f}$). The phenotype of $F_2$ individual plants was recorded at R2 and R3 growth stage from field. One-thousand 10-mer oligonucleotide RAPD primers and 29 SSR primers selected from the D1b+W of the soybean molecular linkage map were used. A genetic map was constructed from the segregating 35 RAPD, four SSR markers and one phenotypic(wild type/fasciation) marker. The segregation ratios of 3 : 1 observed in the $F_2$ population and the Chi-square values strongly suggest that the fasciation trait is controlled by a single recessive gene. Satt537 marker was linked to $\Large f$ locus at a distance of 9.6 cM. Assignment of the $\Large f$ locus to linkage group D1b+W and identification of markers can be used as an initial step for fine mapping of the $\Large f$ gene.

• Fisheries and Aquatic Sciences
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• v.11 no.2
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• pp.82-87
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• 2008

Marine fisheries are important natural resources and must be maintained, especially fish species that are important sources of food. Despite the increase in stocking programs to maintain fisheries with artificially raised fish, the genetic impact stocking has on the wild fry population has not been addressed. Genetic variation in rock bream, Oplegnathus fasciatus, within and between wild-caught parents and the $F_1$ generation produced by them in 1 day was assayed using nine highly variable micro satellite markers. The nine micro satellite loci used in this study displayed diverse polymorphisms, and in total, 98 different alleles were observed over all loci. Differences in genetic variability of the $F_1$ offspring compared to their wild-caught parents (brood stock) were observed in terms of allele frequency, gene diversity, and heterozygosity. Although the $F_1$ generation of rock bream was missing 16% of the micro satellite alleles, no significant reduction was found in mean heterozygosity of the $F_1$ population compared to the brood stock. Eight of nine loci showed significant Hardy-Weinberg equilibrium (HWE) deviations in the $F_1$ population, while the brood stock deviated from HWE at three micro satellite loci (KOF85, KOF360 and KOF374). These deviations showed mostly a deficit of heterozygotes. Our results provide evidence for genetic differences in the $F_1$ hatchery offspring compared to their wild-caught parents and reinforce the need for a series of consecutive egg collections to avoid the loss of genetic variability. This also further underscores the importance of monitoring genetic variability of hatchery populations for the conservation of natural rock bream resources.

• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.1-6
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• 2006

We investigated the characteristics of the nonlinear magneto-optic effect (NMOE) depend on the transitions, the laser intensity and the temperature of the vapor cell, in the $D_1$ transition of $^{87}Rb$ atoms by using the Rb vapor cell contained with buffer gas of Ne 6.7 kPa. The size and the width of NMOE signal were increased according to the light intensity and temperature in the transition of F=2$\to$F'=2. However, In the case of using the F=2$\to$F'=1 transition, the size of the signal could be increased according to the light intensity without additional broadening of the width. We confirmed that the sensitivity of detecting small magnetic flux improved in this transition, and explained these effects by the different of the CPT configuration between Zeeman sublevels. At the optimal condition in experiment, the sensitivity of this system was evaluated less then $70pT/\sqrt{Hz}$.

• Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.151-155
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• 2012

We used nine microsatellite DNA markers to estimate genetic variation among wild and cultured populations of the sea squirt Halocynthia roretzi. The loci were polymorphic, with 6-32 alleles, and allelic richness ranged from 6.0 to 26.1 in each population. The wild and the cultured populations had similar mean heterozygosities ($H_O$ and $H_E$), allele numbers, and allelic richness. One cultured population with softness syndrome had a lower mean in the observed heterozygosity ($H_O$ = 0.57) and higher mean inbreeding coefficient ($F_{IS}$ = 0.261) than any other populations. This suggests that the loss of genetic variation in the diseased population might be due to increased inbreeding. A neighbor-joining tree and pairwise population estimates of $F_{ST}$ showed moderate genetic differentiation between the wild and the cultured populations. Additionally, the softness syndrome population was genetically divergent from wild populations, but it was genetically close to the cultured populations.