• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.39-46
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• 1980

A male sterile facilitated recurrent selection population was developed by the barley breeding team of Yeongnam Crop Experiment Station. To breed this population, three composite cross populations and a composite population of breeding lines in our country were used as the materials. This population was developed in order to breed early maturing, wet-soil tolerant and high yielding barley varieties, adapted for double cropping with rice in southern part of Korea. The population was named by RSPYB#l which means Recurrent Selection Population No.1. of Yeongnam Barley.

• The Korean Journal of Mycology
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• v.20 no.2
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• pp.149-153
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• 1992

This study aimed to investigate possible cause of slow and abnormal growth of oyster mushrooms, Pleurotus florida and P. ostreatus collected from bad crop farms. Spherical virus particles of 30 nm in diameter from P. florida, 23 nm particles from P. ostreatus, and both 23 and 30 nm particles were also found from interspecies mated culture between P. florida and P. osreatus. The virus particles might be associated with the bad crop of Pleurotus species.

• Journal of Sericultural and Entomological Science
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• v.16 no.2
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• pp.55-75
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• 1974

Transovarial transmission of cytoplamic polyhedrosis virus in the silkworm was studied by observing the phenomena of induction, interference and virulence enhancement in the larvae from moths inoculated with hexagonal Polyhedra of cytoplasmic polythedrosis virus. The experimental results obtained are as followings. 1. The effect of inoculation with tetragonal polyhedra of cytoplasmic polyhedrosis virus on the rate of infective induction with hexagonal polyhedron virus and with hexagonal plus tetragonal polyhedron viruses in the larvae from moths infected with hexagonal polyhedron virus was studied. Infection rate was higher by 40 to 60 percent in the larvae from infected female group than in tile larvae from noninfected female group. 2. In the studies of the effect of formalin-feeding on the induction of infection with hexagonal polyhedron virus, infection rate was higher by 40 percent in the larvae from infected female group than in the larvae from noninfected female group. However, there was no significant difference in the infection rates between the two formalin-concentration groups. 3. The effect of cold treatment on the induction of infection with hexagonal polyhedron virus was studied. Infection rate was higher by 50 percent in the larvae from infected female group than ill the larvae from noninfected female group. No difference was found in the infection rates of the two treatment groups of 12 and 48 hours. 4. The phenomena of induction and interference were studied by observing rate of infection with hexagonal polyhedron virus induced by the inoculation with tetragonal polyhedron virus. The degree of interference of primary hexagonal polyhedron virus by secondary tetragonal Ployhedron virus was increased as the dosage of secondary virus was increased. At the concentration of 1${\times}$10$\^$8/m1 of the secondary virus, the degree of interference was similar to. that of control group. On the other hand, infection with tetragonal polyhedron virus at low concentration was interfered by the primary virus. At the concentration of 1N10f/m1 of tetragonal polyhedron virus, however, the rate of infection with tetragonal polyhedron virus was increased sharply, which is still lower by 30 percent than that of control group. 5. In the studies of induction and virulence enhancement, based on the 1ate of mixed infection with hexagonal and tetragonal polyhedron viruses, the highest difference of infection rate between experimental group and control group exceeded 40 percent when the concentration of tetragonal polyhedron virus was 1${\times}$10$\^$7/m1. However, the infection rate of control group was not affected by concentrations of tetragonal polyhedron virus.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.61-68
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• 2003

Considerable attention has been focused on the cryopreservation of semen and estrus induction in dog, as consequence of poor productivity caused by long anestrus period, in order to enhance the productivity of youngs and to preserve the breeds. The objectives of this study were to improve reproductive efficiency of artificial insemination with fresh- and frozen-semen following estrus induction in dog. Fifty infertilie dogs (age 2~3 years) were selected fur the study and divided into three different estrus induction treatment groups. Group 1 : dogs (n=15) were given clomifene (0.1 mg/kg) orally f3r five days at 12 hr intervals. Croup 2: dogs (n=15) were given bromocriptine (50 $\mu$g/kg) orally for five days at 12 hr intervals, followed by single injection intravenously of 500 IU GnRH (Croup 3, n=20) when pro-estrus occurred. After being treated, the dogs were evaluated fur the rates of estrus induction and time interval lapses from treatment to beginning of the pro-estrus. The rates of pregnancy in estrus inducted dogs mated naturally compared to those inseminated artificially with ejaculated fresh semen and frozen-thawed semen. Estrus detection was performed using the method of vaginal smear and confirmed by the plasma progesterone assay. Pregnancy was confirmed by ultrasonograpy on day 25, 35 and 55 post insemination. The ejaculated semen was exposed to a mixture of Tris extender with cryoprotectant (Trisma, 81 mM; TES, 209 mM; citric acid, 6 mM; glucose, 5 mM; glycerol, 8%) and cryopreserved gradually by slow-cooling at 17 co above the surface of liquid nitrogen (L$N_2$) for 23 min. The use of fresh semen, the pregnancy rates were observed 66.6, 66.6, 75.0 and 83.3% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. The use of frozen-thawed semen, the pregnancy rates were observed 66.6, 33.3, 50.0 and 60.0% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. No difference was observed in the number of offspring produced among natural estrus and treated groups inseminated with fresh or frozen-thawed semen. In conclusion, there was no significant differences in the pregnancy rate of dogs between group treated with a combination of GnRH and bromocriptine and group treated clomifene or bromocriptine only. However, frozen-thawed semen can be used successfully fur artificial insemination in dog.

• Journal of Life Science
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• v.23 no.6
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• pp.728-735
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• 2013

Plantago asiatica (Plantaginaceae) is a wind-pollinated plant that grows mainly on fields in East Asia. Starch gel electrophoresis was used to investigate the allozyme diversity and population structure of 18 populations of this species. Although the plantain populations were isolated and patchily distributed, they maintained a high level of genetic diversity; the average percentage of polymorphic loci was 57.1%, the mean number of alleles per locus was 2.07, and the average heterozygosity for 18 populations was 0.201. The combination of a predominant wind-pollinated, mix-mating reproduction, large population sizes, high gene flow between subpopulations, and a propensity for high fecundity may explain the high level of genetic diversity within populations. A direct gradient in overall genetic diversity is associated with latitude. Genetic diversity of P. asiatica is markedly decreased from $35^{\circ}3^{\prime}$ to high latitude and decreased from $35^{\circ}3^{\prime}N$ to low latitude, whereas there does not show a longitudinal gradient in genetic diversity.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.160-163
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• 2011

A new rose cultivar was bred by crossing the red-yellow standard cultivar 'Konfetti' and pink standard cultivar 'Laser' at the Chungcheongbuk-do Agriculture Research and Extension Services. The cross was completed in 2003, after varietal characteristics was tested for 3 years from 2005 to 2007, 'Suryeo' was finally selected in 2007 and registered on the grant of plant variety rights in 2009. The cultivar was developed for a standard-type cut flower with white-pink petals. 'Suryeo' produced 149 stems/$m^2$ in a year and had 64 petals per flower. This new cultivar needed 48 days to flower and showed 12 days vase life. The length of cut stem was about 78 cm, and the fresh weight of stem was 50 g. This cultivar showed high resistance against powdery mildew.

• The Korean Journal of Malacology
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• v.24 no.2
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• pp.121-130
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• 2008

In other aquaculture species, large improvements in growth have been achieved through selective breeding. Ezo abalone(Haliotis discus hannai) and disk abalone(H. discus discus) are major aquatic animals cultured in Asia, but selective breeding for the promotion of growth with these abalones has not been actively pursued. Recently significant efforts are being made to promote production of these species through selective breeding in Korea. The aims of this work were to estimate the general genetic parameters, heritabilities, and genetic and phenotypic correlations on growth-related traits at 1-year old in two Korean abalone subspecies, H. discus hannai and H. discus discus, by using multiple trait animal model. The data were collected from the records of 1,504 individuals produced from 22 sires and 26 dams in H. discus hannai and 297 individuals produced from 5 sires and 6 dams in H. discus discus, which evaluated by the Genetics and Breeding Research Center, National Fisheries Research & Development Institute(NFRDI). Genetic parameters were estimated for these abalone subspecies raised in Bukjeju branch, NFRDI, from May 20, 2004 to May 16, 2005, respectively. The heritability estimates obtained from restricted maximum likelihood(REML) were higher than expected, ranging from 0.40 to 0.43 for growth traits shell length, shell width and body weight in H. discus hannai and from 0.26 to 0.51 in H. discus discus, respectively. The heritabilities for shell shape and condition factor were lower than others of growth traits such as ranging from 0.09 to 0.19 in H. discus hannai and from 0.10 to 0.23 in H. discus discus, respectively. Genetic and phenotypic were > 0.93 between shell parameters and weight in two abalone species, respectively, indicating that breeding for weight gains could be successfully achieved by selecting for shell length.

• Korean Journal of Poultry Science
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• v.12 no.2
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• pp.53-57
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• 1985

This study was carried out to estimate genetic correlations among broiler body weights for the selection of broiler breeders at early age, and to investigate the difference of growth rates between male and female in mixed-sex population of broiler from 2wks to 8 wks of age. A total of 1109 records were used in this study. the heritability estimates from combined variance components for 2-,4-, 6- and 8- weeks body weights were 0.32, 0.31, 0.35 and 0.29 respectively. Genetic correlations were 0.91 between 4wks and 8wks body weights, 0.94 between 6wks and 8wks body weights. Records obtained on 4wks and 8wks might be useful in a selection program to improve traits in 8wks broiler weight. Growth rates of male and female from nonlinear equations from 2wks to 8wks were shown differently in both linear and quadratic terms, Even though both sexes showed closely equal body weights at 2wks of age, they manifested great difference about 300g at 8wks of age. At all. ages roles were havier, grew at a faster than female. From this result it might be profitable either to select the combination of lines which has little sex effect or to rear male and female broiler separately up to the marketing body weights.

• Journal of Mushroom
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• v.14 no.3
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• pp.90-93
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• 2016

'Mantari' is a new variety of oyster mushroom for bottle culture. It was bred by crossing monokaryons isolated from 'DM11732' and 'Chunchu-2ho'. The optimum temperature for the mycelial growth was $26{\sim}29^{\circ}C$ on PDA medium, and that for the primordia formation and the growth of fruiting body of 'Mantari' on sawdust media was $18^{\circ}C$ and $16^{\circ}C$. It took 32 days to finish spawn running, 4 days to finish primordia formation, and 3 days to finish fruiting body growth in the bottle culture. The fruitcharacteristics: the pileus was round and gray-black in color, and the stipe was long, thin, and light gray in color. The yield per bottle was 179 g/900 ml and was 5% higher than that of the control variety (Chunchu-2ho). The physical properties of the fruit body were as follows: springiness, cohesive, gumminess, and brittleness of the stipe tissue were 96%, 76%, 160 g, and 15 kg, respectively.

• Journal of Mushroom
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• v.13 no.1
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• pp.74-78
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• 2015

The 'Heuktari', a new mid-high temperature adaptable variety of oyster mushroom for the bottle culture, was bred by mating with monokaryons isolated from 'P11056' and 'MT07156'. The optimum temperature for the mycelial growth was $23{\sim}26^{\circ}C$ on PDA medium and that for the primordia formation and the growth of fruiting body of 'Heuktari' was $18{\sim}19^{\circ}C$ on sawdust substrate. In case of bottle cultivation, the period of mycelial growth was required about 30 days. In addition, the period of primordia formation and growth of fruiting body was 4 days and 5 days, respectively. In the characteristics of fruiting body, shape and color of pilei were round type and dark grayish brown, stipe color was white color and stipe shape was short and thick. The yield of fruiting bodies was 180 g/900 ml bottle which was 15% higher than that of Suhan-1ho. The gumminess and brittleness of stipe tissue were 110% and 140% stronger than those of Suhan-1ho, respectively.