• International Journal of Industrial Entomology and Biomaterials
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• 제13권2호
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• pp.109-112
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• 2006

The use of commercial silkworm hybrids resistant to important silkworm diseases is economical and better option particularly in tropical areas. This necessitated the evolution of productive bivoltine silkworm breeds non-susceptible to $BmDNV_1$. Non-susceptibility to $BmDNV_1$, infection was found to be controlled by a single recessive gene, nsd-l or a dominant gene, Nid-l. A major dominant/recessive gene confers resistance to $BmDNV_1$, from potent donor parents have been transferred to 10 productive but susceptible bivoltine silkworm strains through conventional breeding methods. By utilizing these breeds prepared 25 hybrids $(5{\times}5)$ and hybrid evaluation was carried out to identify most promising hybrids resistant to $BmDNV_1$. All these hybrids are inoculated with $BmDNV_1$ inoculum along with productive control hybrid $CSR2{\times}CSR4$ and reared under standard rearing procedure. Based on inoculated rearing and test reeling results, two most promising hybrids $(CSR18DR{\times}CSR29DR\;and\;CSR21DR{\times}CSR50DR)$ were selected for commercial exploitation. The selected hybrids have shown a survival rate of >85% with productive traits, where as control hybrid have shown 11.1% survival with inferior cocoon traits. The methodologies adopted were discussed.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권1호
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• pp.33-41
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• 2004

The type of trichomes, their density and pattern of distribution on leaves of 16 genotypes of mulberry, belonging to both diploid and polyploid categories, were studied by scanning electron microscope. The present investigation was undertaken to find out the relationship of physical attributes, especially the density and trichome types with higher acceptability and better rearing performance by the silkworm Bombyx-mori L. Two types of trichomes glandular and non-glandular types were observed on both the leaf surfaces of all the mulberry genotypes studied. In general, greater densities of trichomes were observed on the abaxial surface than the adaxial surface of leaves in most of the genotypes. Distribution of glandular trichomes were more in abaxial surface and non-glandular trichomes were more in adaxial surface. Overall, distribution of glandular and non-glandular trichomes per unit area of leaf did not follow any regular pattern. When leaves of those genotypes were fed to silkworms, trichome density was found to be significantly negatively correlated with the survival of larvae i.e., effective rate of rearing, but trichome density did not influence the economic characters of rearing. As the distribution of glandular trichomes (GT) and non-glandular trichomes (NGT) did not follow any definite pattern, no relation could be established between the GT and NGT densities with silkworm rearing performance. However, the ratio of GT and NGT in a particular genotype influenced the rearing parameters, higher the ratios better the rearing performance. High GT and NGT ratio (＞1.00) was found positively significant when correlated with economic parameters viz., larval weight, single cocoon weight and single shell weight. The study is useful in screening different mulberry genotypes for their better acceptability to silk-worm and higher rearing performance at the early stage of selection without actually conducting the rearing.

• 한국잠사곤충학회지
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• 제17권1호
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• pp.63-68
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• 1975

Flacherie of all other silkworm diseases greatly affects cocoon crop as it is far-reaching and wide spreading. Fleacherie which kills silkworms caused by bacteria can be classified as bacterial digestive organ disease, and "Sotto" disease. Bacterial digestive organ disease is caused by the bacteria living in the silkworms alementary canal and a majority of flacherie belongs to this disease. Septicemia is caused by bacterias breeding in silkworms body fluid but its attach is comparatively limited during the larva period. "Sotto" disease is caused by eating mulberry leaves infected with bacteria which produce toxin and silkworms are intoxicated and killed by the toxin. The cause of flacherie is mainly due to a poor environment. The unclean and unsanitary silkworm rearing beds help bacterias breeding and bacteria enter silkworms body through mouth organ or skin. The present study is to investigate various causes of flacherie by means of pulverization of silkworm. Filtrated fluid is extracted by centrifuge and hypodermic of peroral inoculation-is given to young and medium silkworms of spring and autumn. The gained results of the experiment are summarized as follows： 1. Silkworms infected with flacherie were pulverized and their filtrated fluid was extracted by centrifuge and inspected under microscope to find polyhedron from the fluid. 2. The experimenting group of peroral inoculation. a) From the third day of peroral inoculation silkworms appetite generally decreased and ate less compared with the control group. b) After 7 days of the inoculation silkworms suffered from empty head, loose bowels and fainting. c) Some of the silkworms still ate but as were shown in Fig. 3 and 4 some dwarfish silkworms were found. d) There was no remarkable difference between 1st and 2nd instar inoculation groups. e) There was a tendency that the number of diseased silkworms was decerased as the increase of instars. 2. The experimental group of hypodermic inoculation a) Both of 3rd and 4th instar inoculation groups showed no remarkable singularity and the number of diseased silkworms decreased. b) The rate of diseased silkworms was comparatively low because the body fluid was acidy or toxin was hard soluble. Hypodermic inoculation could not give much harm to the silkworms compared to peroral inoculation.

• International Journal of Industrial Entomology and Biomaterials
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• 제47권1호
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• pp.44-50
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• 2023

The Daehwangjam has excellent marketability and quality. However, precise silkworm breeding data on the recent high-temperature environment is not enough collected, and it is necessary to check whether stable Daewhangjam silkworm egg production was possible in poor environments. In this study, the timing of metamorphosis of the Daewhangjam parents Jam323 and Jam324 silkworms, in an optimal condition and a general condition similar to breeding grounds, was investigated to confirm that appropriate mating was achieved. Surprisingly, a number of female moths were discarded due to the metamorphosis of Jam324 female moths much earlier than Jam323 male moths in either an optimal or a general condition. To improve this, during the Jam324 female pupation period, the mild low-temperature of 15℃ was treated for the pupation period to delay the metamorphosis into female moths. Depending on the treatment period, the metamorphosis of the female pupa was delayed by more than 4 days, allowing normal mating with the Jam323 male moth. The eye pigments in a pupa also slowly accumulated in these treatments. In order to discover the side effects of low-temperature treatments, the voltinism of the Daewhangjam eggs was investigated, but most of them remained univoltine. Taken together, the low-temperature treatment during the female pupation period made it possible to use Jam324 female moths that were should be discarded, which means that stable and efficient management of Daewhangjam egg production is possible.

• 한국잠사곤충학회지
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• 제52권2호
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• pp.117-122
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• 2014

선행연구를 통하여, 형질전환 누에를 제작하는 원천기술을 개발하고 이를 통해 녹색 형광실크를 생산하는 형질전환 누에를 제작한 바 있다. 본 연구에서는 선행연구에서 개발된 녹색 형광실크 형질전환 누에와 국립농업과 학원이 보유하고 있는 누에 유전자원 중 유색견(絹) 누에품종을 이용하여 형질전환 누에와 유색견 누에품종 간 교차교배를 통한 잡종강세를 이용하여 고치 생산량 및 고치의 색채 등이 향상된 녹색 형광실크 형질전환 누에 1대 잡종(F1) 계통을 개발하였다. 본 연구를 통해 선발된 실용형질이 우수한 농가보급형 녹색 형광실크 형질전환 누에 1대 잡종(F1) 계통은 기존 형질전환 누에의 녹색 형광단백질 뿐 아니라 유색견 누에 특유의 천연 연록색도 함께 갖고 있어 별도의 염색이 필요 없는 차별화된 고급 패션의류나 벽지 등의 고품질 소재로 활용이 가능할 것으로 기대된다.

• 한국잠사곤충학회지
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• 제36권2호
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• pp.115-118
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• 1994

뽕잎분말이 포함되어 있지 않은 MP-O 인공사료에 대한 누에의 섭식성의 유전현상을 구명하기 위하여 품종간의 섭식성의 차이와 그 유전양시겡 관하여 실험하였다. 280개 보존누에품종 및 71개 육종계통에 대해 섭식성을 조사한 결과 품종에 따라 현저한 차이가 있었으며 섭식성의 분포는 비정규분포에 가까웠고 저섭식성 쪽으로 편기되어 있었다. 또한 MP-O 인공사료 고섭식성은 저섭식성에 대해 열성적 형질로 판명되었으며 결과적으로 열성유전자에 의해 지배되고 있음이 명확해졌다.

• International Journal of Industrial Entomology and Biomaterials
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• 제10권2호
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• pp.153-157
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• 2005

Recently two breeding programs were carried out for isolation of new parental inbred lines in Iran. This study was undertaken in order to estimate the combining ability effects and heterosis of these lines. For this purpose an $8\times8$ diallel cross analysis including eight inbred lines of silkworm with four lines from each program were studied for their five quantitative traits. The results indicated that reciprocal effects appeared insignificant for most of traits. Japanese lines of 111 and 113 were best combiners for shell weight, cocoon weight and shell percentage traits. With respect to pupation rate, Chinese line 110 was the best and according to general combining ability (GCA) and specific combining ability (SCA) variances, it is superior in specific combinations. Hybrid $109\times110$ showed better characters for both productive and viability traits. Hybrids with high heterosis had high SCA too.

• International Journal of Industrial Entomology and Biomaterials
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• 제25권2호
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• pp.147-151
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• 2012

Fifteen races resulted from silkworm breeding program at Sericulture Research Department (SRD) were used for hybridization. Fourteen hybrids were obtained and coded as; Giza C, D, R, S, T, U, A, V, W, P, H, L and Qanater 1, 2. The traits of cocoon weight, cocoon shell weight, pupal weight, cocoon shell ratio, silk productivity, fifth instar duration, total larval duration, number of cocoon per liter and pupation ratio were evaluated. Data were analyzed by using three formulae of heterosis over better, mid and check parent values. Hybrids of Giza V, C, N, Qanater 1 and 2 are promising and could be used in commercial cocoon production. Generally, there are some new hybrids can be exploited in commercial scale. Also, the local races can be evolved using the hybridization, inbreeding and selection program.

• 한국잠사곤충학회지
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• 제13권2호
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• pp.123-133
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• 1971

The author is the first man who tried to use an anesthetic on insect specially for silkworm in orde to evaluate the silkworm health and silk yielding ability and the obtained results are as followings. 1. The necessary ether vapor induction for narcosis on silkworms is varied by the glowth of the silkworm which the larger worm is, the longer induction is required. For instance, it was 2∼3 minutes for the worms of third day fifth instar silkworm in case use of ether anesthetic. 2. The longer anesthetic induction for silkworms, the longer recovery needs from anesthesia. In case five minutes ether vapor induction, silkworms recovered narcosis during in 5∼130 minutes which had varied very much by the health variation. 3. The ether induction caused silkworm to vomit digestive juice from a few per cent of the worms, but the chloroform induction showed majority of the worms to vomit the digestive juice out of mouth. So, the ether was found as better anesthetic for silkworms. 4. When ether induction last more than 20∼30 minutes, the recovered silkworms can eat mulberry, but when it gets more than three hours they can not eat mulberry. And when it last more than ten minutes, the silkworm may eat mulberry leaf, but they can not spinn cocoon properly. 5. In case five minutes ether induction for silkworms on third day fifth instar, the stronger variety is, the rallier recovered from narcosis. 6. The recovering duration from narcosis varies regarding with each worm health which shows Poisson′s distribution even in a same variety silkworm. 7. The female worms recover from narcosis earlier than male worms which means the female worm is stronger than male one. 8. The later recovered silkworm from narcosis spinned more rich cocoon silk and ended with smaller pupae weight. Such a tendency showed until at some recovery duration, then the silk yield droped down on the worms recovered in more longer duration. The author (Choe) had named such a relation curve as "Silk Yield Curve against Silkworm Health." 9. The silk yield or cocoon layer ratio had varied from 13 to 27% even in a same worm varity cocoon which showed serious variation and call attention carefulness for the duplication work of a variety silkworm eggs. 10. Not always the rich silk yielding worm is the best worm during the silkworm selection and it should be considered with the silkworm health evaluation. 11. At present situation, only specific breeding expert is allowed to join in the selection service because of need many years experience by use of visual observation, but the ether anesthesia method may help such an evaluation with more accuracy and easy way even for the people in fresh on the field. 12. The effect of the narcosis on the silkworm for the next generation or hybrid worm will be reported in next publication.

• 한국잠사곤충학회지
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• 제18권2호
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• pp.101-105
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• 1976

우리나라 장려잠품종의 원종과 교잡종견의 fibroin분해율 및 각종 특수품종견에 대한 fibroin 분해율과 견사형태와의 관계를 구명코저 시험하여 다음 결과를 얻었다. 1. 원종과 교잡종독의 fbroin 효소분해에 있어서 원종은 F$_1$교잡종에 비하여 분해율이 높았다. 2. 양 원종의 평균 fbroin 분해율은 그 교잡종의 분해율과 정상관(r=＋0,86)이 있었고 그 회귀방정식은 y=0.81x＋0.04이다. 3. 교잡종견사 fibroin의 분해율에 있어서 잠103$\times$잠104가 다른 장훈품종에 비하여 분해율이 낮았다. 4. 각종 특수품종 견사의 fibroin 분해에 있어서 품종간에 분해율차리가 인정되었고 견사섬도와 fibroin 분해율과는 낮은 정상관(r=0.6)이 있었다. 5. 이상의 결과에서 견 fibroin 분해율은 유전적 성질을 가지므로 잠품종육종에 있어서 이와 관련된 실용형질 선발에 marker로서 이용될 수 있을 것으로 사료된다.