• Korean journal of applied entomology
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• v.44 no.2
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• pp.151-156
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• 2005

The development of resistance to bifenazate (resistance ratio of egg=40.3 folds) was found in population of the twospotted spider mite, Tetranychus urticae, collected from rose greenhouses in Chilgok, Gyeongbuk Province in December 2000. This population was selected for 4 years with bifenazate treatment (over 150 times), and showed 248.8 folds increase in resistance as compared to susceptible (S) strain. Inheritance of bifenazate resistant strain (R) and cross resistance of this strain to 9 acaricides were investigated. There were differences of susceptibility in the bifenazate concentration-mortality relationships in F1 progenies obtained from reciprocal cross with the S and R strain $(R{\times}S,\;S{\times}R)$. Degrees of dominance were 0.48 and 0.94 in adult females and eggs of $R{\times}S$ and -0.85 and -0.17 in adult females and eggs of $S{\times}R$, respectively. Inheritance type in the F1 progeny of $R{\times}S$ was incomplete dominant, and F1 progeny of $S{\times}R$ was incomplete recessive. These results suggest that inheritance of bifenazate resistance is controlled by a complete dominance. The R strain exhibited cross resistance to acequinocyl and fenpyroximate in adult females, and amitraz, emamectin benzoate, fenpyroximate, milbemectin, pyridaben and spirodiclofen in eggs. However they showed negatively correlated cross-resistance to emamectin benzoate and milbemectin in adult females, and abamectin in eggs.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.2
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• pp.81-86
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• 2005

The mode of transmission, effect on fecundity, hatching and tissues specificity of a microsporidian $(Lb_{ms})$ recovered from Lamerin breed of the silkworm Bombyx mori L. was studied and compared with standard strain Nosema bombycis. Peroral inoculation of $Lb_{ms}$ or N. bombycis to zeroday of $4^{th}$ instar larvae of silkworm was the most suitable method for producing information on development of stage specific mortality, pupation and obtaining infected adults for transovarial transmission studies. It was observed that pupal mortality, the percentage of moths emerged and the percentage of moths infected were significantly high in N. bombycis infected batches as compared $(Lb_{ms})$ in all the three tested breeds of the silkworm. However no significant difference was observed in larval mortality. The fecundity and hatchability was not affected significantly in $(Lb_{ms})$ infected adults, however significant reduction in egg production, fecundity, hatchability and increased egg retention was observed in mother moths infected with N. bombycis. The $(Lb_{ms})$ is transmitted both horizontally and vertically at lower rate due to its low rate of proliferation. The trans ovarial transmission of $(Lb_{ms})$ to the $F_1$ progeny generation through eggs averaged only $61.33\pm5.10\%$ whereas N. bombycis was transmitted at $100\%$. The $(Lb_{ms})$ had low oral infectivity and low transovarial transmission in silkworm B. mori.

• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.277-284
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• 1998

Serum samples were collected from 100 breeders and their progeny 600 broilers. The breeders and broilers were vaccinated against infectious bronchitis(IB), infectious bursal disease(IBD) and Newcastle disease(ND) viruses according to general vaccination program. The antibodies in serum samples against IB, IBD and ND viruses were detected by ELISA using commercial ELISA kit. Geometric mean titer(GMT) of ELISA was monitored from 1-day-old to 35-day-old broilers and compared to that of breeder chickens. The GMT of ELISA to IB, IBD and ND was declined half level of the day old broiler's antibody titers at about 4, 9 and 4 days of age. The GMT of ELISA to IB, IBD and ND was declined than that of protective antibody titer at about 12, 11, and 15 days of age. Thereafter, the GMT of ELISA to IB, ND were declined and disappeared according to age of broilers. The GMT of ELISA to IBD was declined according to age of broilers, but at 25 days of age increased and 31 days of age increased than that of protective antibody titer. Taken together, these studies led to conclusion that time-course of antibody titers of broilers from vaccinated breeders and that of progeny broliers which vaccinated according to vaccine program. Those are very important data to design vaccine program to breeders and broilers.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1621-1627
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• 2001

Steers and heifers (N=490) were produced between 1991 and 1996 by reciprocal fiillsib backcross and $F_1$ crosses from Angus and Brahman to compare characteristics of carcass and palatability traits between Bos indicus and Bos taurus inheritance. Carcasses of 3/4Angus were heavier, fatter (p<0.05), more tender and higher in other palatability attributes (p<0.01) than those of 3/4Brahman. Reciprocal effects of parental cross breeds were found on some traits. Within 3/4Brahman inheritance group, Brahman sired progeny produced heavier and fatter carcasses with better palatability (p<0.05) than progeny with Brahman as a dam breed. Estimates of heritability were intermediate to high in most carcass and palatability traits. Genetic correlations of tenderness with marbling score (MARB), sarcomere length (SARC), fragmentation index (FRAG) and calpastatin activity (CALP) were moderate to high, suggesting potential use of the tenderness-influencing factors as indirect selection criteria to improve palatability attributes. MARB and SARC that were best predictors of tenderness explained 3.07 to 5.85% and 4.32 to 8.24% of variation in tenderness, respectively. However, there was no tenderness-influencing factor to dominantly explain large portion of variation in tenderness.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.485-495
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• 1991

This experiment was carried out to obtain the information on the crossability, variation of chromosome number in pollen mother cell (PMC) and somatic cell of the progeny from the cross between hexaploid triticale cv. Sinkihomil and two diploid rye varieties. Seed set was 39.3 to 41.6% (averaged 40.5%) in the cross between triticale (P$_1$) and rye(P$_2$), which resulted in 0.33% in F$_2$(selfed F$_1$), 2.69% in F$_1$/P$_1$ 5.47% in F$_1$/P$_2$ respectively. However, seed set was extremely low in both reciprocal crosses when triticale was used as male. Germination rate of the crossed seed was 94.0% in F$_1$ 40.8% in F$_2$(selfed F$_1$), 59.5% in F$_1$/P$_1$ and 65.9% in F$_1$/P$_2$ from the cross between triticale and rye, respectively. Pollen fertility of F$_1$ plant was averaged 18.7% in the cross between triticale and rye. Number of Uni-, Bi-, and Trivalent in PMC was 12. 6, 6.94, and 0.53, respectively, in the F$_1$ between the triticale and rye. There were 28 chromosomes in F$_1$, 21 to 34 in F$_2$, 34 to 38 in F$_1$/P$_1$ and 19 to 23 in F$_1$/P$_2$ from the cross between the triticale and rye, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1378-1385
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• 2002

The importance of direct genetic, maternal, heterosis and epistatic effects were examined on post-weaning weight, height, length, girth, fat depth and muscle (ratio of stifle to hip width) with dry and wet season gains in these traits. The breeds used were two pure breeds (Jersey and Limousin), the Limousin${\times}$Jersey $F_1$, and two backcrosses ($F_1{\times}$Jersey dams and $F_1{\times}$Limousin dams). Direct genetic effects were large (p<0.001) for all traits except for length. Jersey maternal effects were large for weight, girth, fat depth and muscle in the post-weaning wet season gains which is an evidence of the impact of Jersey dam on progeny beyond weaning. There were large heterosis effects on fat depth and muscle relative to other traits. Epistatic effects were observed for post-weaning performance in weight, girth, fat depth and muscle. There are indications that there were different genetic effects for post-weaning compared to preweaning growth traits. Thus, it could be hypothesized from this study that different quantitative trait loci (QTL) affect early and late growth in Jersey and Limousin cross cattle breeds. The follow up work will examine the different chromosomal gene effects on pre- and post-weaning growth.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.10
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• pp.1354-1363
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• 2010

This study compared the effect of four different feeding methods for gestating gilts on reproductive performance and growth of their progeny. A total of 40 F1 primiparous sows (Yorkshire${\times}$Landrace) were allotted to four treatments in a completely randomized design (CRD). For treatments, gestating period of sows was divided into three trimesters (0-35 d, 36-90 d and 91-110 d) and different amounts of feed were provided to each treatment group by Flat, Down-Up-Down (DUD), Up-Down-Up (UDU) and Down-Up-Up (DUU) feeding methods. The experimental diet was formulated to meet or exceed the standards of NRC (1998). Body weight gain of gestating gilts from d 0 to 110 was affected by feeding method (p<0.05). When gilts were fed constant feed ration (Flat feeding), less body weight loss was observed during lactation (-0.9 kg, p<0.05) and desirable backfat thickness (average 19.5 mm) was acquired at 110 days of gestation. Feed intake of lactating sows tended to be greater (4.22, 3.60, 3.97 and 4.13 kg/d, p>0.05) as sows in Flat feeding treatment had lower backfat thickness during gestation compared with other treatments (p<0.05). When gestating gilts were fed higher amount of feed during mid-trimester, the number of stillborn (1.4 piglet per litter, p<0.05) and mummies (0.8 piglet per litter, p = 0.25) were increased compared to other treatments. Feeding methods for gestating gilts had no effect on litter weight and gain of litter weight during the nursing period. Flat feeding method resulted in decreased plasma glucose concentration at 7 d postpartum (p<0.05), and increased LH concentration at 21 d postpartum (p<0.01) compared to other treatments. These results suggested that higher feed intake of gestating gilts resulted in detrimental effects on body condition and reproductive performance of sows. When gestating gilts consumed constant feed during gestation (2 kg/d), better reproductive performance and less body weight loss in lactation were observed because sows consumed more feed during the whole lactation period. Consequently, Flat feeding will be a desirable feeding strategy for gestating gilts to maximize reproductive performance, and better body condition of sows without any negative influence on the growth of their progeny.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.463-467
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• 2009

Interspecific hybrid plants between Allium cepa L. (2n=2X=16) and A. fistulosum L. (2n=2X=16)and their backcross lines were developed by artificial pollination in order to introduce new desirable characters of A, cepa to A. fistulosum. The 2C nuclear DNA content has been estimated by flow cytometry in 5 Allium fistulosum inbreed lines, 2 interspecific hybrid lines of A. cepa${\times}$A. fistulosum and 34 their backcross lines $BC_1F_1$ to $BC_2F_2$, using propidium iodide (PI) as a fluorescence dye. Estimated 2C DNA values ranged from 22.2 pg to 23.7 pg in 5 A. fistulosum inbreed lines, 37.9 pg in F1 hybrid between A. cepa and A. fistulosum, 24.3 pg to 27.3 pg in 7 backcross lines in $BC_1F_1$, 21.9 pg to 24.4 pg in 9 $BC_1F_2$, 22.9 pg to 25.1 pg in 14 $BC_2F_1$, 22.6 pg to 23.4 pg in 4 $BC_2F_2$. This study showed mean 2C nuclear DNA content of $F_1$ hybrid was higher than their backcross progeny lines, while it was lower than female parental line, A. cepa (2C DNA=33.2 pg). Mean 2C DNA content of backcross lines, $BC_1F_1$ to $BC_2F_2$ was not significantly different but their 2C DNA contents in the more progress generation from $BC_1F_1$ to $BC_2F_2$ were reduced.

• Journal of Aquaculture
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• v.9 no.2
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• pp.125-132
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• 1996

A study was carried out to test sex ratio of the progeny that were induced by the artificial fertilization between normal female and gynogenetic diploid eggs and sex-reversed gynogenetic diploid male sperm. Sex reversed gynogenetic diploid males were produced successfully in gynogenetic diploid female by immersion treatment with $17{\alpha}$-methyltestosterone at the concentration of 10 pub from $13.5{\pm}0.22$ mm to $57.6{\pm}5.1$ mm in total length. In $F_1$ progeny test, matings between normal females and sex-reversed gynogenetic males were not produced all female, but matings between gynogenetic diploid females and sex-reversed gynogenetic males were produced all female populations in six out of eight groups and two lots produced $96.9\%$ and $95\%$ female. These data showed that all-female populations were produced by crossing between gynogenetic diploid female and sex reversed gynogenetic diploid male.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.310-318
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• 1991

This experiment was carried out to obtain the information on the variation of chromosome number in pollen mother cell (PMC) and somatic cell of the progeny from the cross between hexaploid triticale cv. Sinkihomil and five hexaploid wheat varieties. The results were summarized as follows: Number of uni-, bi- and tri-valent in PMC was 11.9, 14.4 and 0.44, respectively, in the F$_1$ between triticale and wheat. Significant positive correlation between the pollen fertility and seed set rate, pollen fertility and bivalent number of PMC, and seed set rate and bivalent number of PMC, and negative correlation between pollen fertility and uni-or tri-valent of PMC in the cross between triticale and wheat were detected. F$_1$ (crossed seed) had 42 chromosomes, F$_2$ and F$_1$/P$_1$ showed high frequency of hyperploid (42-49) and F$_1$/P$_2$ showed high frequency of hypoploid (36- 42), which suggest non-random segregation for somatic chromosome number. in the cross between the triticale and wheat.