• Journal of Sericultural and Entomological Science
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• v.26 no.1
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• pp.35-51
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• 1984

In order to know the similarity of the electrophoretic protein patterns, distributional aspects of the frequency in each protein band, differences of protein patterns between female and male, and the number of the total protein bands of each variety in the haemolymph of the silkworm pupae according to their geographical origin, the silkworm varieties, and both the sexes, variable electrophoretic protein patterns were observed by polyacrylamide gel electrophoresis, using the silkworm strains which have been reared in the sericultural experiment station. 1. The total number of electrophoretic protein bands classified were twenty-eight, and nearly fourteen bands were shown by each variety on an average. 2. According to their geographical origin, the mean values of the similarity were 20.0%, 28.3% and 14.3% in Japanese, Chinese and European respectively, and the highest similarity was observed between Chinese varieties. 3. The similarity of 129 varieties were tested and it was 22.5%, 23.5% in female and male respectively. 4. The electrophoretic protein patterns in 129 varieties were tested and variation was found in 109 patterns in female and 112 in male. 5. The frequency of the each specified protein band in female and male having variation in protein bands in each variety was found averagely 6.6%. 6. The distribution frequency of the classified 28 protein bands in both the sexes within each geographical origin was variable from 0% to 100%. 7. Among the classified 28 protein bands, HP 11 protein band was found common in all the varieties tested. 8. HP 3 and HP 4 protein bands in female showed high density in electropherograms than in male.

• Journal of Sericultural and Entomological Science
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• v.50 no.1
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• pp.5-9
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• 2012

A new silkworm variety SooOkJam for spring rearing season is F1 hybrid between Jam157, a japanese race bred from introduction breeding and Jam158, a chinese race from introduction breeding. In the local adaptability test performed at 8 local areas in spring of 2011, the hatchability rate of SooOkJam was recorded 2% higher than the authorized silkworm variety, DaePoongJam. The larval period was recorded 12 hour shorter than DaePoongJam. The pupation percentage was recorded 0.8% higher than DaePoongJam. Single cocoon weight (2.40 g), Cocoon yield (22.6 kg) and best cocoon rate (95.5%) was similar to DaePoongJam. The concentration of DNJ was measured 4.12 mg in SooOkJam, lower than DaePoongJam (4.45 mg). Test of the artificial diet of SooOkJam showed excellent adaptability of the artificial diet for larval period from 1st to 3rd, similar to KumOkJam. In the Paecilomyces tenuipes production ability test, the pupal weight of SooOkJam was 1.61 g/individual, similar to DaePoongJam (1.65 g/individual).

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.2
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• pp.175-182
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• 2002

A new high yielding mulberry genotype, Victory-1 (V-1) was recommended to the field for irrigated areas by Central Sericultural Research and Training Institute (CSRTI), Mysore during 1996-1997. As K-2 and S-36 mulberry genotypes are already in the field, a study on the comparative performance of V-1, 5-36 and K-2 varieties, in terms of leaf yield, yield attributes, leaf moisture and moisture retaining capacity and their impact on silkworm rearing was carried out under Telangana conditions of Andhra Pradesh during 1999-2001. Among the three genotypes the leaf yield was found to be significantly (P < 0.01) higher in V-1 (64,130 kg/ha/yr) followed by S-36 (44,064 kg/ha/yr) and K-2 (23,990 kg/ha/yr). The maximum leaf moisture was also observed in V-1 (71.84%) compared to S-36 (66.86%) and K-2 (64%). The moisture retaining ability was more in V-1 (70.17%) followed by S-36 (66.20%) and K-2 (60.08%). The yield attributes were found to be significantly (P < 0.01) enhanced in V-1 over S-36 and K-2. Silkworm rearing results (bioassay) indicated a significant (P < 0.01) reduction in larval duration and improvement in larval weight, effective rate of rearing by number and weight, single cocoon and shell weights and shell ratio in the silkworm lots fed on V-1 variety followed by S-36 and K-2. Hence, in this study, V-1 was found to be superior among the three varieties studied.

• International Journal of Industrial Entomology and Biomaterials
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• v.24 no.1
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• pp.17-21
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• 2012

The effect of cultivation season on the cocoon filament quality of authorized silkworm variety, GoldenSilk was examined with cocoon filament character, reeling character, and fiber character during 3 years. In cocoon filament character, filament length of spring and autumn cocoon was 979 and 879 m, respectively. Cocoon filament weight of spring and autumn cocoon was 33.1 and 26.5 cg, which is lower than that of general bivoltine strain, BaeGokJam. Raw silk percentage of spring and autumn cocoon was 15.65 and 13.77%, respectively. In reeling character, reelability showed similar trend regardless of cultivation season and strain. However, the length and weight of non-broken filament of spring season were slightly higher than those of autumn cocoon. Cultivation season did not affect on the fiber characteristics such as clearness and neatness, lousiness, and degumming loss. In cocoon character, filament length, size, and weight, spring cocoon filament showed higher value than autumn cocoon, but lower than authorized general silkworm varieties. In reeling characteristics, non-broken length and weight showed the similar trends with the cocoon filament character. However, the reelability of GoldenSilk cocoon was not affected by cultivation season. The reelability of GoldenSilk cocoon was also similar with that of authorized general one. Fiber character including clearness and neatness, lousiness, and degumming loss was also similar regardless of the rearing season and different strain.

• Journal of Life Science
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• v.32 no.12
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• pp.947-955
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• 2022

Silkworms, which have recently shown promise as functional health foods, show functional differences between varieties; therefore, the need for variety identification is emerging. In this study, we analyzed the whole silkworm genome to identify 10 unique silkworm varieties (Baekhwang, Baekok, Daebaek, Daebak, Daehwang, Goldensilk, Hansaeng, Joohwang, Kumkang, and Kumok) using single nucleotide polymorphisms (SNP) present in the genome as biomarkers. In addition, nine SNPs were selected to discriminate between varieties by selecting SNPs specific to each variety. We subsequently created a decision tree capable of cross-verifying each variety and classifying the varieties through sequential analysis. Restriction fragment length polymorphism (RFLP) was used for SNP867 and SNP9183 to differentiate between the varieties of Daehwang and Goldensilk and between Kumkang and Daebak, respectively. A tetra-primer amplification refractory (T-ARMS) mutation was used to analyze the remaining SNPs. As a result, we could isolate the same group or select an individual variety using the nine unique SNPs from SNP780 to SNP9183. Furthermore, nucleotide sequence analysis for the region confirmed that the alleles were identical. In conclusion, our results show that combining SNP analysis of the whole silkworm genome with the decision tree is of high value as a discriminative marker for classifying silkworm varieties.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.2
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• pp.141-151
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• 2002

The success of sericulture industry in India is mainly attributed to the well-planned annual sericultural activity and the systematic implementation of pest preventive and control measures. The insect spectrum of silkworm and its food plants is complex and plays a major role in limiting the production of silk. Insects cause extensive damage to plant whereas predators and parasites either kill the silkworm larvae or force them to spin flimsy cocoons. Unilateral control measure against this pest is mainly based on the use of synthetic organic insecticides. Though these approaches initially paid rich dividends, the undesirable consequences soon surfaced. Insecticide induced resurgence of gall midges, leafhopper, leaf roller, secondary pest out breaks and development of pest biotypes has led to realization of Integrated Pest Management in sericulture. Various components of IPM, viz. Host plant resistance, cultural practices, biological control, chemical control and integrating them at various technological levels have been studied. Sources of host plant resistance have been identified for some of the major insect pests. High yielding mulberry variety has been propagated and their resistances towards major pests have been recorded. Cultural practices like pruning, pollarding, judicious use of nitrogen, optimum spacing and weed management have preyed to be the powerful tools in containing pests. Natural control over the pest population build- up exerted by the wide range of parasitoids, predators and pathogens has been well documented with identification of natural enemies and studies on their potential. Augmentation, through inoculation or inundative releases of parasitic arthropods, is the most direct way of increasing the numbers of these beneficials in sericulture.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.93-102
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• 2002

We have cloned and characterized the complete fibroin light chain gene from the silkworm Baekok-Jam, Bombyx mori, a recommended variety in Korea. It consists of seven exons and six introns. It consists of 14,663 nucleotides long with an open reading frame of 786 nucleotides that encodes a protein of 262 amino acid residues with a molecular mass of approximately 26,000 dalton. The amino acid alignment revealed that the Baekok-Jam fibroin light chain had 98.5 % protein sequence identity to J139 strain: differed at four amino acid positions (11, 46, 80 and 123). The Northern hybridization analysis showed that the Baekok-Jam fibroin light chain gene was specifically expressed in the posterior silk gland.

• Journal of Sericultural and Entomological Science
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• v.15 no.2
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• pp.15-20
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• 1973

This will be second publication regard with silkworm selection using anesthetic followed by previous report. This treatise investigated for nacorsis recovery concerned with silkworm health through more directions than the previous paper. After the author has found a possibility of silkworm seperation through nacorsis recovery, he has recommended to use Balance Health (BH) value system to evaluate or identify silkworm health and to produce better homogeneous silkworm eggs. Also, the author has continued the observation for the next generation how once nacortized parents affect to their family. The obtained results are summarized as followings. 1. Basic investigation a) Hybrid silkworm variety recovers from nacorsis earlyer than pure line because it is stronger. b) Strong pure line variety recovers from nacorsis earlyer than weak one because it is stronger. c) Male worm recovers from nacorsis earlyer than female worm because it is stronger. 2. Establishment of Balance Health(BH) value system. In order to identify each seperated group by nacorsis and their family, the following Balance Health (BH) value indicating system was established.(Table Omitted) 3. In order to select better silkworm during breeding service, the BH value indicating system is strongly recommended. That is, in case BH value is smaller than four, it would be strong group or in case BH value is larger than four, it would be weak group. 4. Once nacortized parents do not harm any nature for next generation regardless P$_1$ or F$_1$ production. 5. The seperation through nacorsis may delay retrograde phenomenon some years than other case, so, this system should be used for pure line production every year. 6. It is recommended to nacortize silkworm for five minutes on breeding purpose, but two and half minutes on pure lines reproduction at fifth instar. 7. This report has been discussed in relation to practical industry promotion aspects, but there are many subjects to be solved from academical aspect in future

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.487-497
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• 2019

Fetal Bovine Serum (FBS) is an essential substance added to animal cell culture medium. However, its composition is unclear causing problems such as development of an immune response when cultured cells are transplanted into the human body. In this study, silk sericin, silk fibroin, and hemolymph obtained from silkworms were added to the cell culture medium in order to determine if it can replace FBS. After establishment of the cell culture, cell proliferation and expression levels of cell growth-related genes were compared with those of control cells (cells cultured in the medium with 10% FBS). Results showed that the test group treated with silk fibroin extracted from a Korean silkworm variety, Kumokjam could replace 10% FBS. In addition, expression levels of cell growth related genes such as Fibronectin and TGF-β1 increased significantly in cells cultured using silk fibroin, depending on the concentration used in cell adhesion and cell proliferation [24]. To date, no studies have been conducted to find a replacement for FBS. Thus, this study was carried out to develop a substitute for FBS by using silkworm-derived alternatives such as silkworm hemolymph, silk sericin, and silk fibroin, which are cheap and have various physiological effects, cell promoting effects, and can be mass produced.

• Mycobiology
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• v.39 no.3
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• pp.158-163
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• 2011

This study was conducted to confirm the possible use of female Yangwonjam as a host for synnemata production of Isaria tenuipes in eight local areas in Korea. Silkworm pupation rate, infection rate and synnemata characteristics of I. tenuipes were examined. Normal silkworms had a higher pupation rate than silkworms inoculated with I. tenuipes. The pupae survival percentage of normal silkworm in cocoons was 92.5~97.6%, whereas it ranged from 91.1~95.6% in silkworms sprayed with I. tenuipes. Female Yangwonjam showed the highest survival percentage at 97.6% among the silkworm varieties tested. I. tenuipes infection rate of larvae of 5th instar newly-exuviated silkworms was 89.2~90.7% in the spring rearing season and 98.2~99.3% in the autumn rearing season. Synnemata production of I. tenuipes was excellent in female Yangwonjam with an incidence rate of 98.0% followed by male Yangwonjam (94.1%) and Baegokjam (93.3%) in the spring rearing season. Synnemata living weight ranged from 1.44~0.94 g in the spring rearing season. The female Yangwonjam had the heaviest synnemata weight (1.44 g) in the spring rearing season. The synnemata of I. tenuipes produced on pupae were white or milky-white in color, and were similar in shape and color to wild synnemata collected in Korea.