• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.155-165
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• 1992

Experiments were conducted to determined the development of the vascular bundles in the peduncle of different tillers on its development in order to improve the vascular system and possibly increase grain yield. The development of the vascular bundle in the leaf, stem and panicle is an important aspect of assimilate translocation and differentiation of panicle characters. Two cultivars were used in this study: IR58, an indica type, and Unbong 7, a japonica type. The main culm(M) had more and bigger vascular bundles in the peduncle and those vascular bundle decreased with tiller order and tiller development. In the primary tillers, P1 had more large and small vascular bundles than P5 in both cultivars. IR58 developed more large vascular bundles compared to Unbong 7, but the small vascular bundle in unbong 7 was more than in IR58. The cross sectional area of phloem and xylem in large vascular bundle decreased with tiller order in both cultivar. Larger area of phloem and xylem in the early formed tillers more efficient transport of assimilates. The number of spikelets, the weight of panicle and grain yield per panicle were highest in the main culm followed by the order of their initiation or emergence. The number of primary and secondary branches to be positive associated with the number and area of vascular bundles. Furthermore, the number of vascular bundles in the peduncle was highly correlated with the peduncle thickness which in turn was correlated with the number of primary and secondary branches on the panicle. These results showed tillers that are initiated early and have relatively ation usually have more vascular bundles, larger peduncle, more spikelets spike let filling and ultimately higher yield.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.117-121
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• 1999

Development and reproduction of the sycamore lace bug, Corythucha ciliata, were investigated under different temperature regimes. Duration of development from egg to pre-adult of the sycamore lace bug measured seven temperatures ranged from 54.0 days at 18$^{\circ}$C to 17.9 days at 33$^{\circ}$C. Development was not successful at 15$^{\circ}$C and 35$^{\circ}$C. Developmental zero point and total effective temperature for development of egg, nymphal, and complete development were 1 1 .O, 10.9, ll.l$^{\circ}$C and 150.3, 230.6, 376.1 degree-days, respectively. Longevities of adult females varied to temperature from 51.8 days at 18$^{\circ}$C to 17.2 days at 33$^{\circ}$C. The average fecundity per female was greater at 25$^{\circ}$C and 28$^{\circ}$C compared with at other temperatures. The intrinsic rate of natural increase (r,) and net reproduction rate (R,) were highest at 28$^{\circ}$C as 0.170 and 73.25, respectively. As a result, optimum ranges of temperature for C. ciliata growth were between 25$^{\circ}$C and 28$^{\circ}$C.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.461-467
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• 2012

Developmental characteristics of Geocoris pallidipennis were investigated at a constant temperature ($20{\pm}1$, $25{\pm}1$, $30{\pm}1$, $35{\pm}1$, $37.5{\pm}1$ and $40{\pm}1^{\circ}C$), under long day illumination 16:8 (L:D) and constant relative humidity ($80{\pm}10%$). From egg to adulthood, the lower developmental threshold and the effective accumulative temperature were $14.8^{\circ}C$ and 399.1 day-degree, respectively. The experimental results at $35^{\circ}C$ were as follows. The egg period was 5.6 days (hatchability: 81.1%) and the nymphal period was 14.3 days (1st: 3.2, 2nd: 2.2, 3rd: 2.7, 4th: 2.7, 5th: 3.6). Female longevity was 33.8 days and the oviposition period was 29.2 days. Total egg production was 111.2 eggs and the maximum daily egg production was 14.8 eggs (in 7th days). However, although some eggs and nymphs developed at $37.5^{\circ}C$, G. pallidipennis could not develop at $40^{\circ}C$, The total egg production at $40^{\circ}C$ was only 22.1 eggs. When G. pallidipennis was fed on Bemisia tabaci pupae, daily prey consumption by nymphs (1st, 3rd and 5th) and adults was 1.9, 7.3, 18.7 and 29.5, respectively.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.333-338
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• 2006

The purpose of the present study was to clarify the sexual difference of the Heath-Carter somatotype related variables in boys and girls from 7 through 19 years of age. In the study design, the subjects and the methods were used by the cross-sectional investigation. The subjects participated in this study were 7 through 19 years of age who belonged to typical primary, junior, senior high school and college students, and about 250 males and 250 females in each group and both sexes. Therefore, the total subjects were 3,046 males and 2,984 females. All subjects of this study lived in Pusan metropolitan city, Korea. Somatotype was calculated by the Heath-Carter's anthropometric somatotype method, In this study, in attaiment rates of sum of 4 sites skinfold and endomorphy growth, girls were significantly higher than boys in all ages intervals except through 13 years of aged groups, respectively. In attainment rates of humerus and femur breadths growth, boys were significantly higher than girls in all ages interval except 13 through 15 years of aged groups, respectively. In attainment rate of arm circumference growth, boys were significantly higher than girls in all ages interval except 7 years of aged group. In attainment rate of calf circumference growth, boys were significantly higher than girls in all ages interal except 15years of aged group. In attainment rate of ectomorphy growth, boys were significantly higher than girls in all aged interal except 8 thorough 12 years of aged groups. This results suggests the urgent necessity of developing systematic and sperate progams to treat such sexual difference in boys and girls.

• Korean journal of applied entomology
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• v.50 no.1
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• pp.55-63
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• 2011

This study was conducted to develop an artificial diet for the mugwort looper, Ascotis selenaria (Lepidoptera: Geometridae), which is an insect pest to leaves of citrus (Citrus unshiu). Corn and soybean powder were selected as main nutrient sources for larvae of A. selenaria after several diets consisted of wheat germ, corn, kidney bean and/or soybean were tested for larval development and survival. A higher amount of the main nutrients in the diet increased the larval survivorship. Addition of yeast and cholesterol in diet increased the larval survivorship. Finally the composition of diet was decided as followings; corn 100 g, soybean 100 g agar 25 g, Brewers' yeast 30 g, cholesterol 0.5 g, Vanderzant vitamin mixture 2 g, Wesson's salt mixture 2 g, sorbic acid 2 g, ascorbic acid 2 g, and methyl-4-hydroxybenzoate 2.5 g, and distilled water 1 liter. Development periods of larvae and pupae, survival rate and fecundity of A. selenaria reared on the diet were not significantly different with those on the host plant, citrus leaves. Larvae of early instars were reared in a group, while larvae of later instars (5-6th) were reared individually. Adult mating was conducted in a plastic cage and an oilpaper covered with a gauze was provided as an oviposition site.

• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.39-47
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• 1986

본 연구는 한개의 뇌하수체를 이식시켜 과배란된 미성숙 흰쥐에서 초기태아 발육과 착상효과를 관찰하기 위하여 시도되었다. 30일령 숫컷 흰쥐에서 뇌하수체를 제거하기 15일 전에 정소를 제거시켰으며 정소가 제거된 쥐에서 얻은 한개의 뇌하수체를 실험 시작일(임신 3일전 : D-2) 오전 7시에서 10시 사이에 28일령의 암컷 흰쥐의 우측 신장 피막 아래 이식시켰다. 대조군은 같은 날 오전 10시에 4 IU PMSG를 투여하였다. 실험에 사용된 쥐들은 난소 및 자궁 무게의 변화를 조사하기 위하여 임신 3일전, 2일전, 1일전, 임신 1일, 2일, 3일 및 5일에 희생시켰다. 또 다른 쥐들은 난 회수 및 난소를 관찰하기 위하여 임신 1일, 2일, 3일 및 5일에 희생시켰으며 임신 8일에는 착상 상태를 조사하였다. 임신 1일에는 질도말법에 의해 발정주기를 조사하였다. 본 실험에서 얻은 결과는 다음과 같다. 1. 뇌하수체를 이식시키거나 4 IU PMSG를 투여함으로써 발정 동기화를 이룰 수 있었다. 뇌하수체를 이식시킨 쥐와 대조군에서 임신 1일 전인 발정전기에 있는 흰쥐는 각각 64.7%, 71.3%이었다. 2. 뇌하수체 이식군 및 대조군의 교배율은 각각 75.0% 및 80.2%였으며 첫 배란은 각 처치후 3일 이내에 일어났다. 3. 과배란된 흰쥐에서 임신 1일에 황체화된 난포와 임신 황체수는 평균 $46.1{\pm}2.9$개였으며 임신 2일부터 그 수는 임신 1일 보다 많았다. 4. 과배란된 흰쥐에서 회수된 난의 수는 임신 1일과 2일에 각각 평균 $46.1{\pm}2.9$ 및 $49.8{\pm}4.2$개였으며 대조군은 $8.6{\pm}0.3$ 및 $8.9{\pm}0.4$개로 나타났다(p<0.001). 5. 임신 3일부터 과배란된 흰쥐에서 난의 회수율은 임신 2일과 비교할 때 현저하게 감소되었으며 (p<0.001) 난의 발육은 지연되거나 퇴행되었다. 난 발육단계의 분포는 임신 3일과 5일에 특히 변이가 많았다. 6. 과배란된 흰쥐에서 임신 8일에 착상 부위수는 대조군에 비해 현저한 증가를 보였으며(p<0.001), 18마리의 과배란된 흰쥐 중 특히 10마리에서는 $28.1{\pm}0.7$개의 착상부위가 확인되었다. 7. 과배란된 흰쥐의 난소 무게는 임신 1일전부터 임신 3일까지 계속 증가하였으며 대조군은 이 기간동안 큰 변화가 없었다.

• Reproductive and Developmental Biology
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• v.30 no.1
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• pp.59-64
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• 2006

This study was conducted to establish a convenient freezing method of boar semen. Boar semen was cooled until $5^{\circ}C$ for 3 hrs using cell freezer and loaded into straws. Semen straws were frozen in different steps in strofoam box filled with $LN_2$. Highest sperm viability (54.0%) was obtained by 1-step freezing(holding at 10 cm height from the surface of $LN_2$ for 10 min). Sperm viability increased by holding at $-102^{\circ}C$ for 10min (74.0%, P<0.05). In thawing regime, sperm viability was significantly higher in $37^{\circ}C$ group than in $52^{\circ}C$ group. The sperm characteristics did not differ between 1-step and 3-step. After IVF using frozen-thawed boar semen, developmental rate of embryos to the morula+blastocyst stage was in 1-step freezing group than that of 3-step freezing group (27.5 vs 14.7%, P<0.05). The result shows that the 1-step freezing with holding at $-102^{\circ}C$ for 10min before plunging into $LN_2$ is a convenient and easy freezing method for boar semen.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.371-376
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• 2012

This study was conducted to predict the hatching time of eggs of Lycorma delicatula, to select an effective environmentally-friendly agriculture material (EFAM) and to evaluate the attraction effect of brown sticky traps for controling of Lycorma delicatula nymph and adults. Eggs hatched 55.9, 26.8, 21.6 days after incubation at 15, 20, $25^{\circ}C$ with 14L:10D condition and the hatching rates of egg were 61.9, 57.8, 30.4%, respectively. At high temperature conditions, egg development periods were shorter and the hatching rate was lower. The relationship between temperature and developmental rate was expressed by the linear equation Y=0.0028X-0.0228, $R^2$=0.9561. The low temperature threshold of eggs was $8.14^{\circ}C$ and the thermal constant required to reach larva was 355.4 DD. According to this relationship, the mean estimated hatching date was $22^{nd}$ May. The effective EFAM was natural plant extract, sophora extract, derris extract to nymph and natural plant extract, pyrethrum extract, sophora extract to adult. Among three colors of sticky trap : brown, blue and yellow, the brown sticky trap was the most attractive to nymphs and adults of L. delicatula over a 2 weeks trial period. It suggested that the brown sticky trap could be a very useful and environment-friendly control method for nymphs and adults of L. delicatula.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.287-293
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• 2023

A lot of individuals of Mythimna loreyi have been attracted to the sex-pheromone traps of Spodoptera frugiperda during recent few years. However, there is no information about this pest. Thus, an efficient mass-rearing method of M. loreyi is demanded to study this pest. In this study, we compared the effects of artificial diets and rearing methods on its larval development and oviposition to suggest an efficient mass-rearing method of M. loreyi. Between S. frugipera and Agrotis ipsilon artificial diets, A. ipsilon diet showed more rapid larval development with higher survivorship, and decreased pupa weights and oviposition numbers compared to S. frugipera diet. Moreover, a grouping rearing caused more rapid larva development, decreased pupa weight and survivorship compared to an individual rearing. Therefore, for mass-rearing of M. loreyi, it is considered efficient to rear the newly emerged larvae in groups using A. ipsilon artificial diet and then rearing them individually after second or third larval stadium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.455-461
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• 1987

The ovaries or the ovules of grasses were pollinated and cultured in vitro to raise the interspecific or the intergeneric hybrids between tall fescue, meadow fescue, and Italian ryegrass. The isolated and suface-sterili-zed pistils were dusted with compatible pollens on stigma, on stump after removing stigma, or on excised ovule. Furthermore, the fertilized ovaries and ovules were cultured on MS, M6, or White's media and treated with plant growth regulators: IAA, kinetin, BA to promote embryo development and seed maturity. The in vitro fertilization in grass species ranged from 44 to 92% depending on ovary and pollen parents. The stigmatic pollination was resulted in 67.8% fertilization, the stump pollination 89.0%, and the excised ovule pollination 61.0%, repectively. White's medium was the most effective to provide embryo development and seed maturity in grass species. And the combined treatment of IAA 10mg/$\ell$, kinetin 0.2mg/$\ell$, was better than the non-treatment. Only two seedlings, one complete and one abnormal with root formation were obtained from 127 ovaryies cultured. The anatomy of ovules in vitro cultured was revealed the differentiation of vascular system and meristematic tissue, and the formation of sclerenchyma cells inside ovule.