• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.77-81
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• 2002

A new non-cocooning silkworm variety, Hachojam, suitable for autumn rearing season is single cross Fl hybrid between Japanese race Jam 307 and Chinese race Jam 126. Jam 307, Japanese parent of the Hachojam, which is a source for non-cocooning process showed a high GCA (generation combining ability) in naked pupation rate and Jam 126, Chinese parent, showed a high GCA in pupation rate and single pupal weight. In the local adaptability test performed at 8 local areas in autumn of 1999 to 2000, the naked pupation rate and thin cocoon rate of Hachojam were 64.7% and 35.3% , respectively. The pupal weight calculated from 10,000 of the 3rd molted larvae was 24% heavier in Hachcjam than the cocoon-producing, check variety Daesungjam.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.249-254
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• 2004

Dietary supplementation of sodium nitrate with different concentrations 50, 100, 200, 500, 700 and 1000 $\mu\textrm{g}$/ml of single, two, three and four feeds to fifth instar larvae of biovoltine NB$_4$D$_2$ race of the silkworm, B. mori resulted in significant increase in the food conversion, conversion rate and conversion efficiency $K_1$ and $K_2$. However, there were significant decrease in the food assimilation, assimilation rate and assimilation efficiency in the sodium nitrate treated groups as compared with that of the corresponding parameters of the carrier control. This indicates that the administration of sodium nitrate may stimulate metabolic activities, thereby influencing conversion of food into body weight in the bivoltine silkworm, B. mori.

• International Journal of Industrial Entomology and Biomaterials
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• v.43 no.2
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• pp.99-103
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• 2021

In the present study, twelve bivoltine silkworm races were evaluated for its performance based on quantitative and qualitative traits. Seven oval and five peanut cocoon shaped races were reared in different seasons of the year. By using evaluation index method, the results showed that six races were identified as potential parental races. Among oval races, 75xin, KoC, KoZ and among peanut races An 902, 7532 and QD7 were selected as base material. The identified high yielding races will be used in various breeding programs as initial parents for the production of superior bivoltine breeds/hybrids in Vietnam

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.89-93
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• 2004

A new silkworm variety, Kumhwangjam, with a sex-limited cocoon color for spring rearing season is F$_1$ hybrid between Jam 309, a Japanese race bred from Y1/9153, and Jam 310, a Chinese race from Y1/8586. In the local adaptability test performed at 8 local areas in spring rearing season of 2003, major characteristics of Kumhwangjam were mainly similar to those of the check variety Kumokjam. The new silkworm variety, Kumhwangjam, showed a sex-limited cocoon color: yellow for female and white for male with elliptical cocoon shape. This sex-limited cocoon color can be used as a valuable marker for discrimination between female and male for various purposes.

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.154-166
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• 1999

General characteristics and life span of silkworm moth were investigated amongst 277 gene resources preserved and maintained in Korea. Silkworm varieties were classified according to the commercial characteristics and the viability of tested varieties. There were significant differences among the eight different commercial characteristics of silkworm such as whole larval period, duration of 5th instar, pupal body weight, single cocoon weight, cocoon shell weight, cocoon shell ratio, cocoon yield and longevity, Tropical race showed the longest life span among the other five geographical races, and followed by Japanese, European, Chinese and Korean race in order. In the longevity of each variety, Daizo(sdi) showed the shortest life span with 4.3days, and J037 was the longest as 16.0 days. Average longevity of female was 11.1 days as showed 3.0 days longer than that of male which was 8.2 days. Total average longevity of the whole varieties was 9.7days. In the correlation between the longevity and commercial characteristics, there was a tendency that the commercial characteristics became better when the life span was longer. According to the result of Complete Linkage Cluster Analysis, the genetic resources of 277 silkworm varieties classified into 5 groups such as “Group I”for short life span with low cocoon yielding “Group II”for middle life span with middle cocoon yielding,“Group III”for the shortest life span with low cocoon yielding, “Group IV”for high pupation rate and the highest cocoon yielding with comparatively long life span, and “Group V”for the longest life span with comparatively high cocoon yielding.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.45-48
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• 2003

We have previously cloned and characterized the complete fibroin L-chain gene from one of the silkworm races Baekok-Jam (Bombyx mori) and found two variable regions (I, intron 2 ~ exon 3; II, intron 6) with the primer sets designed to cover these variable regions. We tested the utility of these regions as genetic markers among silkworm races. For the purpose of study, Japanese race (Jam 123), Chinese race (Jam 124) and their F$_1$hybrid Baekok-Jam were used. The PCR product size of region I was 787 bp in Jam 123, 770 bp in Jam 124 and 768 bp in Baekok-Jam. The size of region II was 470 bp in Jam 123, 428 bp in Jam 124 and 429 Up in Baekok-Jam. In the extended experiment, Jam 125 (Japanese race), Jam 126 (Chinese race) and their F$_1$hybrid Daeseong-Jam were also analyzed. The sizes of region I and II in Jam 125, Jam 126 and Daeseong-Jam were similar to those of Jam 123, Jam 124 and Baekok-Jam. DNA sequence divergence between the two geographic races of Jam 123 or Jam 125 and Jam 124 or Jam 126 was substantial. The result suggests that the fibroin L-chain gene of F$_1$hybrids were inherited from Chinese races. These results are concordant with cocoon shapes of tested animals, and suggested that Baekok-Jam or Daeseong-jam is more closely related to Jam 124 or Jam 126 than to Jam 123 or Jam 125. Taken these data together, the primer sets designed from two variable regions of fibroin L-chain gene would be highly useful, as the genetic markers for silkworm races, at least in Japanese and Chinese races, although an extended study including more geographic races is required.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.21-27
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• 2003

Manifestation of heterotic genetic interaction was studied in different hybrids made between multivoltine recurrent backcross (RBL)/congenic lines (Con. L) during unfavourable season when temperature and relative humidity are > $30^{\circ}C$ and 86%, respectively. A few number of silkworm race or strain or breed like Nistari (N ＋ p or Np) can sustain the temperature above 3$0^{\circ}C$ and RH above 86%. The present heterosis study screened a hybrid i.e., CB$_{5}$Lm5RBL1M$_{6}$DPC-LmE$^1$RBL and its reciprocal provided heterobeltiotic effect on survival by number and pupation rate at a magnitude of 20% (p < 0.01) and yield by weight of 10% (p < 0.01). Beside all the hybrids expressed heterosis over check - Nistari (N ＋ p) with better quality silk. Therefore, aforesaid hybrid may be useful for utilization at commercial level during adverse seasons of West Bengal.gal.

• Journal of Sericultural and Entomological Science
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• v.6
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• pp.9-17
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• 1966

The ratio of form and character in the text generation of silkworms which were double copulated between home race copulation and hetero race copulation in crossing with two males of different races for female(double crossing) are different according to the copulating time, copulating order and sperm activities. But the general tendencies are as follows; 1. During two hour's double copulation, sufficiently ejaculating time, the fertilization percentage of hetero lace copulation are higher than that of homo race, but in case of double copulation with plain and normal marked silkworms showed opposite results. The fertilization percentage of homo race copulation are equal or higher compare with that of hetero race copulation. 2. The form and character of the next generation were largely effected by copulating order, so the primary copulating moths are more effected in the next generation than the secondary moths. 3. The active sperms were more fertilized than non-active sperms in the double copulation.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.1
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• pp.120-127
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• 2014

The cerebral neurosecretory cells (NSC) constitute four paired groups, medial (MNC), lateral (LNC-I, LNC-II) and posterior (PNC) in the brain of larvae of tasar silkworm Antheraea mylitta (D) Eco-race Bhandara. The MNC is the largest groups of peptidergic neurosecretory cells and are located in the pars intercerebralis region. The transmission electron microscopic (TEM), ultrastructure of the NSC confirmed the presence of mitochondria, endoplasmic reticulum, Golgi bodies, lysosomes and neurosecretory granules. The median neurosecretory cells shows secretory activity and release of secretory products, the neurosecretory granules (NSG) in the axons of NSC as well as the blood sinus.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.57-61
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• 2003

A new silkworm variety, Chugangjam, with a sex-limited larval marking and high silk yielding for summer-autumn rearing season is $F_1$ hybrid between Jam 147, a Japanese race bred from P8503/8453, and Jam 148, a Chinese race from M8306/Jam 130. Jam 147, Japanese parent of the Chugangjam showed a high GCA (general combining ability) in pupation percentage and Jam 148, Chinese parent, showed a high GCA in pupation percentage and single cocoon weight. In the local adaptability test performed at 8 local areas in autumn of 2001, Chugangjam was 5% higher in cocoon yield and 8% in raw silk productivity in the 10,000 of the 3rd molted larvae, respectively, than the check variety Daesungjam.