• Journal of Life Science
• /
• v.31 no.11
• /
• pp.1010-1018
• /
• 2021

Although varieties of silkworms, which have recently attracted attention as a health functional food, are being produced, studies on the differences in the functionality of different silkworm varieties are insufficient. Therefore, in this study, the antioxidant activities of different silkworm breeds bred in domestic farms were analyzed, and the potential for their cultivation as specialized varieties with excellent antioxidant function was investigated. To compare antioxidant activity, four varieties of silkworms, white Bakokjam, Golden silk, Yeonokjam, and Hanseongjam, were bred; water and ethanol extracts of these silkworms were prepared on the 3rd and 5th days of the 5th instar larval stage. The highest extraction yield was seen for the water extract from the Golden silk variety on the 3rd day of the 5th instar; the highest total phenolic compound and flavonoid contents were observed for the water extract (86.11±4.04 ㎍/mg GE) and 70% (v/v) ethanol extract (46.70±2.81 ㎍/mg QE). Bakokjam and Yeonokjam exhibited DPPH radical scavenging activity of up to 78% and showed the highest nitrite scavenging activity (85%) at pH 1.2. The maximum SOD-like activity of Yeonokjam was about 47%. Furthermore, 48 ㎍/ml of the Yeonokjam extract showed a reducing power of 0.7 abs, which was the best among the four varieties. Considering these results, the Yeonokjam (on the 3rd day of the 5th instar) had antioxidant activity and represents a silkworm cultivar that would be suitable for cultivation as a health food.

• Journal of Sericultural and Entomological Science
• /
• v.51 no.1
• /
• pp.73-77
• /
• 2013

Silkworm transgenesis scientists have done some genetic modification work on multivoltine silkworms, but that type of silkworms is less commercial feasible. They are easy to manipulate, because they breed all year round. But the commercial silkworm variety must undergo hydrochloric acid treatment at a high temperature to be artificially hatched. Hydrochloric acid penetrates through the holes in the silkworm eggs, fatally damaging their reproduction. So it had been thought that altering the properties of the commercial silkworm variety would be very difficult. So we have tried to make from diapause to non-diapause eggs using diapauses varieties, 'Backokjam' and 'Jam 124'. At present, our group has establishing the conditions for non-diapause eggs. Oviposited eggs after 40 ~ 60 hours were incubated for 24 hours at $15{\sim}20^{\circ}C$ with dark condition. Non-diapause eggs were completely induced. The hatching rate, molting rate and pupation rate of non-diapause 'Jam 124' and 'Backokjam' eggs showed no differences compared to diapause eggs. When transgenic silkworm using the non-diapause eggs, the hatching rate showed that non-diapause eggs induced from diapause were 40 ~ 70%, diapause eggs treated with artificial incubation were 10 ~ 30%, and polyvoltine strains, HM eggs were 30 ~ 50%. Therefore, we suggest that modification techniques of the commercial silkworm eggs adequate for silkworm transgenesis can be used to develop transgenic silkworms more easily.

• Journal of Sericultural and Entomological Science
• /
• v.23 no.1
• /
• pp.38-46
• /
• 1981

In order to investigate a suitable carbohydrate-resources and the activities of starch decomposing enzymes in artifical diet of silkworm, the experiment was undertaken by adding eight kinds of starch in the diet of silkworm. Major characters and zymograms of amylase in body organs were studied by electrophoresis. The results obtained are as follows: 1. Starches of rice, barey and millet were comparatively good for maintaining practical characters of silkworm. 2. It is assumed that no treatments are need to increas purity of starch resources for artificial diet of silkworm. It was found that starch amounts adding to artificial diet are moeerate ranging 12 to 18 percent as dry weight. 3. Regardless of kinds of starch and varieties of silkwormr sametype of electrophoresis zymogram for amylase was resulted as three bands in hemolymph, four bands in intestine and two bands in intestine and two bands in silkgland. There was no band in the digestive juice. In case of 18 percent addition of starch and check plots, no amylose change was investigated in the hemolymph.

• Journal of Sericultural and Entomological Science
• /
• v.6
• /
• pp.28-30
• /
• 1966

The aim of this experiment was to investigate the method of discrimination of male and female depending upon the specific gravity of pupa in silkworm varieties which are being recommended in Korea at present. The results obtained are as follows: 1. The specific gravity of silkworm pupa existed between 1,000 and 1,100. 2. Female pupae went to the bottom of salt water(NaCl), around 1,020 of specific gravity, while male pupae came near to the surface of salt water. 3. Salt water of around 1,020 specific gravity was not harmful to the pupa, egg laying ability and moth emerging ability. 4. The effect of salt water on the other useful characters will be assigned to the next chance, and also the device of cocoon cutting machine is being studied.

• Journal of Sericultural and Entomological Science
• /
• v.30 no.1
• /
• pp.20-24
• /
• 1988

Adult specific proteins, referred to as ASP-I(adult specific protein of slow mobility) and ASP-II(adult specific protein of slow mobility) at the pharate adult stage of the silkworm, Bombyx mori, were detected by polyacrylamide gel electrophoresis. The adult specific proteins (ASP-I and ASP-II) were defined as a kind of adult hemolymph proteins without sex specificity, and the was no variation in the respective electrophoretic mobility of ASP-I and of ASP-II among the forty-one silkworm varieties. tested.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.32 no.2
• /
• pp.54-59
• /
• 2016

All of silkworm varieties reared in farmhouses are first generation hybrids, for the production of these hybrid silkworms precise and labor-saving sex discrimination is necessary. The new variety "Hanbyeolnue" is biparental sex-limited larval marking yellow cocoon variety which was bred from biparental sex-limited strain of Japanese originated Jam 319 and Chinese originated Jam 320. Productivity test of Hanbyeolnue in 2015 showed high healthiness and short larval period. The Hanbyeolnue was evaluated as an excellent variety which can be utilized for special purpose silkworm such as male pupae or Cordyceps production.

• Journal of Sericultural and Entomological Science
• /
• v.13 no.2
• /
• pp.151-154
• /
• 1971

In the silkworm egg production, cutting of the cocoon's edge formed by silkworms forced to aid the emergence, and emergence is related to the amount of alkaloid liquid in the sucking stomach in certain varieties. In this study, there was no difference between cutting of portion and sex, and no significant between cutting of both sides and one side cocoons when comparing their emergence ratio. Expenditures and emergence ratio between both sides and one side cutting off must be studied in coming future.

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

• Mycobiology
• /
• v.38 no.2
• /
• pp.128-132
• /
• 2010

Injection inoculation protocols for fruit body formation of Cordyceps militaris (C. militaris) were investigated to improve the incidence of infection in the silkworm species Bombyx mori (B. mori). Injection, with suspensions of C. militaris hyphal bodies into living silkworm pupae, was used to test for fruit body production. Use of Daeseungjam rather than Baegokjam or Keumokjam varieties of B. mori is thought to be suitable for infection by C. militaris. From mounting, nine-day-old to 11-day-old pupae showed the best incidence of infection with a $100\;{\mu}L$ injection volume. Silkworm pupae injected with a hyphal suspension concentration of more than $2\;{\times}\;10^5$ colony-forming unit (cfu) recorded a greater than 96% incidence of infection. Also, fruit bodies of C. militaris were induced and produced at a light intensity between 500 and 1,000 lx.

• Journal of Sericultural and Entomological Science
• /
• v.2
• /
• pp.41-47
• /
• 1962

This work was carried out to investigate the phenotypic, genotypic, and environmental correlations between the number of the egg markings and other metric characters, and their heritability, with eight varieties in Bombyx mori L. Five European varieties, ten Chinese varieties and ten Japanese varieties were used to know the average number of the egg markings and their variabilities for each strains. The results may be summarized as follows: 1) there were highly negatively phenotypic and genotypic correlations between the number of the egg markings and total cocoon weight, weight of cocoon layer, or denier, but not an environmental correlation. 2) The average number of the egg markings in Chinese strain was more than that in other strains. 3) The correlation between the motality and the number of egg markings seemed not to be found. 4) The heritability of the weight of cocoon layer and the bave length was less than that of total cocoon weight, denier and number of egg markings. 5) The more the number of the polyhedral particles in an egg marking group became, the more the total number of egg markings increased. 6) The variation of the number of the egg markings in European strain was larger than that in any other strains. 7) It is expected that the selection for the number of the egg markings may have genetic advances of total cocoon weight, weight of cocoon layer, or denier. Especially the selection for the number of the egg markings before rearing will save the silkworm rearing cost.