• Journal of Aquaculture
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• v.10 no.4
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• pp.449-456
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• 1997

This study was concuted to determine the optimal conditions for raising the freshwater rotifer, Brachinus calyciflorus. The authors presented some biological informatin obtained from incubation experiment under the various controlled temperatures. Lorica size of the rotifer was divided into two groups : the length and the width for the S-type was $141.0\pm16.7\mu m$($110.1-182.5\;\mu m, n=44$)and $107.0\pm20.3\mu m\;(75.3-152.3\mu m, n=44)$, and those for the L-type was $262.8\pm15.2\mu m\;(234.4-288.6\mu m,\;n=20)\;and\;182.6\pm13.4\mu m (159.8-207.0\mu m,\;n=20$), respectively. The number of eggs being attached on the female varied from 1 to 11 at various culture conditions. Egg type was divided into two groups, large and small. Large and small egg was measured in its major axis as 85a.7-107.8$\mu$m and 55.1-65.2$\mu$m for S-type, and 104.9-121.8 $\mu$m and 62.8-89.1$\mu$m for L-type respectively. The maximum density was reached at 4th day after incubation. The density was 583.9 rotifers/$m\ell$ for $25^{\circ}C$-experimental. group and 421.3 rotifers/$m\ell$ for $22^{\circ}C$-experimental. group respectively. In the case of $28^{\circ}C$-experimental. group, it suddenly decreased into 4.7 rotifers/$m\ell$ at 1st day after incubations and did not recover to its initial density. The maximum rate of increase of populatin per day was reached 0.802 for $22^{\circ}C$-experimental. group at day 2 and fluctuated thereafter. For $25^{\circ}C$-experimental. group it increased to 0.964 at day 3 of incubation and then declined. And the egg ratio of female was reached the maximum of 0.614 for 22$^{\circ}C$- at 3rd day and 0.772 for $25^{\circ}C$-experimental. group at 4th day of incubation.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.519-523
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• 2011

''Nokyang', a new high biomass yield and whole crop silage rice (Oriza sativa L.) cultivar, was developed by the rice breeding team of National Institute of Crop Science, RDA, Suwon, Korea, during the period from 1996 to 2006 and released in 2007. It was derived from a cross between Yongmoonbyeo/IR67396-16-3-3-1. This cultivar has about 130 days of growth duration from seeding to heading and is tolerance to lodging with erect pubescent leaves, semidwarf (culm length 78 cm) and thick culm. This cultivar has less tillers per hill and more spikelet numbers per panicle than Dasanbyeo. 'Nokyang' has wide and stay green leaf compared other Tongil-type varieties. This new variety is resistant to grain shattering and to some disease including bacterial leaf blight and stripe virus. This variety has good qualities for whole crop silage with high TDN (Total Digestive Nutrient) yield and low NDF (Neutral Detergent Fiber) and low ADF (Acid Detergent Fiber) and high RFV (Relative Feed Value) compared to common high grain yield varieties. The biomass and TDN yield performance of 'Nokyang' is 1,652 MT/ha, 9.9 MT/ha, individually in local adaptability test for three years. 'Nokyang' is adaptable to central plain area, south-eastern plain area of Korea.

• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.386-391
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• 2024

'Jinha' is a new strawberry (Fragaria × ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2019. The 'Jinha' cultivar originates from a 2011 cross between 'Albion' and 'Goha,' both of which exhibited excellent ever-bearing characteristics, including continuous flowering and large fruits under long-day and high temperature conditions. This new cultivar was initially named 'Saebong No. 11' after examining its characteristics and productivity during summer cultivation between 2012 and 2016. After regional adaptability tests, 'Jinha' was selected from 'Saebong No. 11' as an elite cultivar. The general characteristics of 'Jinha' include intermediate, elliptic leaves, and medium growth. The fruits are conical and of a red color. The plant height of 'Jinha' is simiar to that of the control variety, 'Flamenco', but it has a lot of number of leaves. The cluster length of 'Jinha' was 35.5 cm, 10.8 cm longer than 24.7 cm of the control variety. The number of flower clusters of 'Jinha' appeared 14.4, which was 4.1 more than that of 'Flamenco'. The average fruit weight of 'Jinha' was 10.1 g, which was 0.8 g heavier than that of 'Flamenco'. The soluble solid content of 'Jinha' was 10.2 °Brix, which was 2.0 °Brix higher than that of 'Flamenco'. The marketable yield of 'Jinha' was 25,931 kg·ha^-1, 440% more than that of 'Flamenco' with 5,900 kg·ha^-1. Therefore, the new cultivar of ever-bearing strawberry 'Jinha' is expected to be very popular in the export or bakery market because it is high soluble solid content and good shape.

• Journal of Korean Society of Forest Science
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• v.21 no.1
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• pp.1-34
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• 1974

The author intended to investigate external and internal changes in the cone structure, changes in water content, sugar, fat and protein during the period of seed maturation which bears a proper germinability. The experimental results can be summarized as in the following. 1. Male flowers 1) Pollen-mother cells occur as a mass from late in April to early in May, and form pollen tetrads through meiosis early and middle of May. Pollen with simple nucleus reach maturity late in May. 2) Stamen number of a male flower is almost same as the scale number of cone and is 69-102 stamens. One stamen includes 5800-7300 pollen. 3) The shape is round and elliptical, both of a pollen has air-sac with $80-91{\mu}$ in length, and has cuticlar exine and cellulose intine. 4) Pollen germinate in 68 hours at $25^{\circ}C$ with distilled water of pH 6.0, 2% sugar and 0.8% agar. 2. Female flowers 1) Ovuliferous scales grow rapidly in late April, and differentiation of ovules begins early in May. Embryo-sac-mother cells produce pollen tetrads through meiosis in the middle of May, and flower in late May. 2) The pollinated female flowers show repeated divisions of embryo-sac nucleus, and a great number of free nuclei form a mass for overwintering. Morphogenesis of isolation in the mass structure takes place from the middle of March, and that forms albuminous bodies of aivealus in early May. 3. Formation of pollinators and embryos. 1) Archegonia produce archegonial initial cells in the middle and late April, and pollinators are produced in the late April and late in early May. 2) After pollination, Oespore nuclei are seen to divide in the late May forming a layer of suspensor from the diaphragm in early June and in the middle of June. Thus this happens to show 4 pro-embryos. The organ of embryos begins to differentiate 1 pro-embryo and reachs perfect maturation in late August. 4. The growth of cones 1) In the year of flowering, strobiles grow during the period from the middle of June to the middle of July, and do not grow after the middle of August. Strobiles grow 1.6 times more in length 3.3 times short in diameter and about 22 times more weight than those of female flower in the year of flowering. 2) The cones at the adult stage grow 7 times longer in diameter, 12-15 times shorter diameter than those of strobiles after flowering. 3) Cone has 96-133 scales with the ratio of scale to be 69-80% and the length of cone is 11-13cm. Diameter is 5-8cm with 160-190g weight, and the seed number of it is 90-150 having empty seed ratio of 8-15%. 5. Formation of seed-coats 1) The layers of outer seed-coat become most for the width of $703{\mu}$ in the middle of July. At the adult stage of seed, it becomes $550-580{\mu}$ in size by decreasing moisture content. Then a horny and the cortical tissue of outer coats become differentiated. 2) The outer seed-coat of mature seeds forms epidermal cells of 3-4 layers and the stone cells of 16-21 layers. The interior part of it becomes parenchyma layer of 1 or 2 rows. 3) Inner seed-coat is formed 2 months earlier than the outer seed-coat in the middle of May, having the most width of inner seed-coat $667{\mu}$. At the adult stage it loses to $80-90{\mu}$. 6. Change in moisture content After pollination moisture content becomes gradually increased at the top in the early June and becomes markedly decreased in the middle of August. At the adult stage it shows 43~48% in cone, 23~25% in the outer seed-coat, 32~37% in the inner seed-coat, 23~26% in the inner seed-coat and endosperm and embryo, 21~24% in the embryo and endosperm, 36~40% in the embryos. 7. The content compositions of seed 1) Fat contents become gradually increased after the early May, at the adult stage it occupies 65~85% more fat than walnut and palm. Embryo includes 78.8% fat, and 57.0% fat in endosperm. 2) Sugar content after pollination becomes greatly increased as in the case of reducing sugar, while non-reducing sugar becomes increased in the early June. 3) Crude protein content becomes gradually increased after the early May, and at the adult stage it becomes 48.8%. Endosperm is made up with more protein than embryo. 8. The test of germination The collected optimum period of Pinus koraiensis seeds at an adequate maturity was collected in the early September, and used for the germination test of reduction-method and embryo culture. Seeds were taken at the interval of 7 days from the middle of July to the middle of September for the germination test at germination apparatus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.18
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• pp.124-155
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• 1975

To obtain the fundamental informations on the varietal improvement of peanut and to study the ecological variations of the important agronomic traits and to the relationship between the traits studied, an investigation was made on varietal classification of 489 introduced on the basis of their morphological and ecological differences at Crop Experiment Station, Suweon in 1968, and the other study conducted at some location as above in 1969 was to investigate the ecological variations of the materials in accordance with changes of seeding date using classified varietal group under 5 different seeding times from April 16 to July 7 with twenty days interval. The results obtained were summarized as follows: 1. Peanut varieties tested were classified into Spanish, Virginia Erect, Virginia Runner, Southeast Runner. Valencia and Semirunner, on the basis of plant type, flowering time, number of grains per pod and grain size. 2. Characteristics of varietal group classified are as followings. (1) Spanish; erect, small grained and early maturing type. (2) Virginia Erect; erect, large grained and late flowering type. (3) Virginia Runner; runner, large grained and late maturing type. (4) Southeast Runner; runner, small grained and early maturing type. (5) Valencia; erect, small grained and early flowering type with 3-4 grains per pod. (6) Semi runner; semirunner, large grained and late flowering type. 3. Flowering period in respective varietal group was consistently shorted by delayed seeding date and the degree of shortening was more serious in late flowering varietal group. 4. Number of branches per plant was generally decreased in late seeding date in respective group. However, Spanish and Virginia Runner exhibited lower number of branches in the first seeding rather than the second seeding and the lowest number of branches was found in Spanish while the highest were Virginia Erect in all seeding date. 5. Shelling ratio was high in Spanish and Southeast Runner in any seeding date and decreased remarkedly by seeding after May. 6. Number of pod per plant in all varietal groups was remarkedly decreased by delayed seeding date and the degree of decreasing was more serious in large grain varietal group. 7. The higher pod weight per plant was found in second seeding date rather than first seeding and pod weight per plant was decreased obviously in all late seeding after the second. Therefore, among the cultivars tested, Southeast Runner noted the highest pod weight per plant while Virginia Runner showed the lowest. 8. Grain number per plant expressed the similar tendency as the pod weight per plant but was low in large grain group and high in small grain group in all seeding date employed. 9. 100 grain weight was heaviest in second seeding and was decreased remarkedly after the second and even the first seeding date. 10. Yield per 10a noted considerable variations in accordance with seeding date in all groups classified. However, the yield was increased in second seeding date (May 7) and decreased in the others. 11. Length of main stem and branches were exceptionally decreased in the first seeding date compare to the second in Spanish while other varieties were tend to be same between the indicated seeding date, but. these two traits were strikingly decreased in all seeding after the second. This tendency, however, strongly suggested the importance of environmental effects on peanut growth in terms of their changes due to the different seeding date. 12. Highly significant positive correlations were showed between yield and yield componets such as pod weight per plant, 100 grain weight and the number of grains per plant in all varietal groups except, Virginia Runner. However, the other characters were almost not correlated with yield and differences in correlation coefficients among the seeding dates were found. 13. Path coefficients estimated for yield components to yield was higher in number of grains per plant pod weight per plant and 100 grain weight in terms of direct effect and the other components were negligible in all varietal groups. 14. Heritabilities estimated were generally high in pod number per plant, shelling ratio, 100 grain weights and number of grains per pod and the other traits were relatively low.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.939-948
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• 2003

The objective of this study was to identify the quantitative traits loci(QTL) for economically important traits such as growth, carcass and meat quality on pig chromosome 6. A three generation resource population was constructed from cross between Korean native boars and Landrace sows. A total of 240 F$_2$ animals were produced using intercross between 10 boars and 31 sows of F$_1$ animals. Phenotypic data including body weight at 3 weeks, backfat thickness, muscle pH, shear force and crude protein level were collected from F$_2$ animals. Animals including grandparents(F$_0$), parents(F$_1$) and offspring(F$_2$) were genotyped for 29 microsatellite markers and PCR-RFLP marker on chromosome 6. The linkage analysis was performed using CRI-MAP software version 2.4(Green et al., 1990) with FIXED option to obtain the map distances. The total length of SSC6 linkage map estimated in this study was 169.3cM. The average distance between adjacent markers was 6.05cM. For mapping of QTL, we used F$_2$ QTL Analysis Servlet of QTL express, a web-based QTL mapping tool(http://qtl.cap.ed.ac.uk). Five QTLs were detected at 5% chromosome-wide level for body weight of 3 weeks of age, shear force, meat pH at 24 hours after slaughtering, backfat thickness and crude protein level on SSC6.

• Korean Journal of Plant Resources
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• v.10 no.1
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• pp.100-104
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• 1997

A new baekji(Angelica dahurica Bentham et Hooker) variety, Baekji l, was developed through a pure line selection at the Gyeongbug Provincial RDA during the period of 1990 to 1995. The variety was characterized to have high plant height. Long root length and large root diameter as compared with a check varicty of Bonghwa baekji but emergence date, flowering date and leaf number of Baekji l was similar to that of the check variety, and it was also more tolerant to nematode and heat stress. Peeled root color of Backji l was yellowbrown but number of the lateral root of the variety was greater. The dried-root yield of Baekji l in yield trial, regional adaptation trial and farmer's field trial was always $21\sim31%$ higher than that of the check variety.

• Journal of Mushroom
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• v.13 no.4
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• pp.314-318
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• 2015

This study was carried out to investigated the avaiability of dried Koojongsi persimmon peels (KPP) as a useful mushroom medium using Pleurotus eryngii ASI 2312. Mushroom cultivation medium used in this study was mixed with medium mixture, corn cob and sawdust (220:65:15, v/v). Dried KPP was replaced mushroom cultivation medium (control) with 5, 10, 15, 20, 30, 40, 50% dried KPP. The T-N content of dried KPP treatments decreased to increase replaced ratio of the dried KPP and C/N ratio was increased to increase replaced ratio of the dried KPP. But T-C content of dried KPP treatments was similar to untreated control. The average cultivating periods of mycelium on dried KPP treatments was delayed to increase replaced ratio of the dried KPP and cultivating periods was delayed over 30% dried KPP treatments. The length of stipe of dried KPP treatments was longer than that of the untreated control to increase replaced ratio of the dried KPP and thickness of stipes was tend to be thinner than that of the untreated control to increase replaced ratio of the dried KPP. The moisture, carbohydrate, crude protein and crude ash content of mycelial were similar to untreated control, but crude fatty acid was increased to increase replaced ratio of the dried KPP. The ${\beta}-glucan$ content of 10% and 15% treatments were higher than untreatment control. The results based on cultivation yield and ${\beta}-glucan$ content indicated that optimal mixture ratio dried KPP was 15%.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.529-532
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• 2008

Manna is a new japonica rice cultivar developed from the cross between Iksan438 and Ilmibyeo by the rice breeding team of Department of Rice and Winter Cereal Crop, RDA, in 2005. This cultivar has a short grain shape and about 97 days growth duration from late transplanting to harvesting under Korean climatic conditions. It is resistant to lodging with average 70 cm of culm length. The milled kernels of Manna are translucent with non-glutinous endosperm. It has about 19% amylose content and good palatability of cooked rice compared with Geumobyeo. This cultivar shows resistance to leaf blast and neck blast but susceptibility to bacterial blight and stripe virus diseases. The milled rice yield potential of Manna is about 5.05 MT/ha under the late transplanting cultivation. Manna would be adaptable for the middle and Honam plain of Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.123-133
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• 1992

This study was conducted to clarify progressed changes of plant types and the effects of the physiological and ecological components on improving ideotype of winter wheat. 12 wheat varieties were planted at the experimental farm of Wheat and Barley Research Institute in Suwon in 1990. As results of intensive wheat breeding for early maturity since 1959, heading, flowering and maturing dates have been shortened by 17, 15 and 14 dagys, respectively. The shortened days from sowing to heading and from heading to flowering contributed to the early maturity to improved. Physiological factors associated with heading time of wheat could be reprsented by growth habit, photoperiod responses, earliness in narrow sense and winter hardiness. For improving an early maturity of winter wheat, it would desired to maintain some degree of winter habit(III-IV), and recombination of more insensitivity to short day length and more shortened earliness in narrow sense than that of Saemil and Chugoku 81, and higher degree of winter hardiness. For improving the early maturity the more effective way must be of shortened days from sowing to heading, and days from flowering to maturity than days from heading to flowering. Ideotype of wheat will be desired to recombine two semi-dwarf genes with erect plant type being about 70-80cm, less stem elongation by late spring, long spike and many grains per spikelet. Average spike weight ratio was about 45-49% in high-yielding varieties, stem fresh weight was lighter, but spike fresh weight was heavier in new one while leaf fresh weight was similar to each other during the maturing periods. Average spike dry weight ratio was higher about 40～48%, and stem and leaf blade dry weights were lower in the newly bred varieties. Stem dry weight was heavier than spike or leaf dry weight in the old varieties of Yungkwang, Jangwang and Jinkwang. Leaf area index for the varieties showed normal distribution curve as the maximum point in booting stage. The maximum point of this curve come in early maturing wheat, and late in old one. The maximum points of LAI were 6.4～6.8 in the high-yielding varieties. Totals of LAI in each period investigated of old one were higher than those of newly bred being 24.6～28.8. Chlorophyll content of the high-yielding varieties of Chokwang, Geurumil and Saemil as higher than that of the old varieties Jangkwang, Jinkwang, Wonkwang and Sinkwang from regrowing period to April 21. after then slightly and even after heading. Net assimilation rate (NAR) was higher in high-yielding varieties with good plant type, and lower in old ones. Grain yield of the newly released varieties increased rapidly but slowly in the old ones. Change in water content of grain at the growing stage in newly bred was lower than that of the old bred. Diminishing rate of water content of grain in establishment per day was 1.2% average that of the old varieties including Yungkwang was 1.5%, and those of the newly bred including Chokwang were 0.9～1.1%. Chokwang, Naemil, and Saemil were the highest-yielding varieties of the Korean cultivars. Yields were increased by spikes per m$^2$, grain weight for the varieties bred in Suwon, and by spikes per m$^2$ for the varieties bred in Milyang.