• International Journal of Industrial Entomology and Biomaterials
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• 제7권1호
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• pp.59-63
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• 2003

In the present study, hybrid vigour in terms of heterosis and over dominance of newly evolved bivoltine hybrids and their reciprocals raised from the promising newly evolved bivoltine breeds were calculated for the important parameters like pupation, cocoon yield, cocoon weight, shell weight, shell ratio, raw silk percentage, filament length and neatness. Through there was no significant difference among the hybrids for the characters pupation, cocoon yield and cocoon weight, the magnitude of heterosis and over dominance were varied significantly for these characters. However, significant differences were observed between new hybrids and control hybrid for the characters like cocoon shell weight, cocoon shell ratio, filament length and raw silk percentage. The results indicate that majority of new hybrids have shown higher heterosis and over dominance than control hybrid. The data also indicate that highest mean heterosis of all new hybrids was recorded for cocoon yield followed by filament length. Whereas highest mean over dominance was recorded for cocoon yield followed by cocoon weight. Negative mean heterosis and over dominance were recorded for the trait cocoon shell ratio. Based on the results, the importance of three hybrids viz., CSR2 ${\times}$ CSR4, CSR2 ${\times}$ CSR5 and CSR3 ${\times}$ CSR6 and their reciprocals (CSR4 ${\times}$ CSR2, CSR5 ${\times}$ CSR2 and CSR6 ${\times}$ CSR3) which exhibited significant heterosis and over dominance, for commercial exploitation was discussed.

• 한국잠사곤충학회지
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• 제32권1호
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• pp.17-30
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• 1990

주성분분석에 의하여 분류된 148개 보존잠품종중에서 제일주성분 score에 따라 10개의 교배모품종을 선발한 후 (정등, 1989), 이들로부터 Top-교잡에 의해 24개 교배조합을 작성하고 조합능력검정을 행함과 동시에 주성분과 교배조합능력과의 상호관계를 분석하였다. 1. 선발된 육종모품종중에서 일본종계 N$_{39}$ 및 중국종계 $C_{46}$ 이 대부분의 형질에서 일반조합능력이 높았다. 2. 특정조합능력은 형질 또는 교배조합에 따라 차이가 심하였다. 3. 육종모품종의 제1주성분 score는 5영경과일수, 전령경과일수, 수견량, 전견중, 견층중, 견층비율, 견사장, 견사량, 해서사장, 생사량비율, 소절등의 일반조합능력과 고도의 정의 상관관계가 있었다. 4. 유사도거리(D$^2$)는 수견양, 해서사장, 해서사량, 해서율, 생사량비율, 소절등의 특정조합능력과 정의 상관이 있었다. 따라서 교배조합의 양친이 원연일수록 이들 5개형질에 대한 특정조합능력은 높게 나타났다. 5. 육종모품종의 특성을 이용한 주성분분석의 제1주성분 score에 의해 일반조합능력의 예측이 가능하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제13권1호
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• pp.7-14
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• 2006

A breeding programme was initiated during 2001 to introduce sex-limited larval markings to a productive multivoltine breed - BL67 from an inbred sex-limited line, MY1 (SL) maintained at Central Sericultural Research and Training Institute, Mysore. Introgressive hybridization, recurrent backcrossing for six generations followed by sib-mating resulted in synthesis of a new multivoltine silkworm breed BL67 (SL) with sex-limited larval markings. The new breed was studied for combining ability by crossing with eight bivoltine breeds viz., $NB_4D_2,\;CSR_2,\;CSR_2 (SL),\;CSR_2,\;CSR_4,\;CSR_8,\;CSR_{18}\;and\;CSR_{19}$. General combining ability effects of the new breed showed its superiority over the popular Pure Mysore by expressing significant GCA effects for six out of twelve characters whereas the results are on par with the original multivoltine breed. The hybrid $BL67(SL){\times}CSR2(SL)$ excelled in several quantitative characters such as pupation rate (90.2%), cocoon weight (1.97 g), cocoon shell weight (40 cg), cocoon shell ratio (20.3%), filament length (918 m), denier (2.96), raw silk percentage (14.96%) and neatness (90 p). Studies on cocoon size variability revealed that the cocoons of $BL67(SL){\times}CSR2(SL)$ were found comparatively uniform showing less standard deviation of 6.55 and co-efficient of variation of 3.91 %. The suitability of newly developed breed for easy grain age operation and commercial exploitation with promising hybrid have been discussed.

• International Journal of Industrial Entomology and Biomaterials
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• 제18권2호
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• pp.97-103
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• 2009

Sericulturists in the vicinity of Bangalore city irrigate their mulberry gardens with Vrishabhavathy stream water, which is polluted with domestic and industrial wastes from the city. To investigate the effect of pollutants on silkworm crops, a detailed field survey was conducted to study the cocoon yield pattern of the crops raised on mulberry irrigated with wastewater as against irrigation by bore/open wells. The villages along the stream were grouped into five test batches at about a distance of $5{\sim}8$ km from each other. The seasonal yield data with relevant information were collected through questionnaires from 117 rearers using stream water and 35 rearers using bore/open wells, the latter serving as control group. The average yield for 100 layings was 46 to 57 kg in the control group whereas in test groups, it ranged between 34 to 51 kg in the first test group and 22 to 38 kg in the rest. The difference in yield was $9{\sim}19$ kg depending on the season between control and test batches. In summer, this difference was higher, with high co-efficient of variation in test groups ($33{\sim}52$%). Further, water, soil and leaf samples were collected from selected rearers and were analyzed for zinc, copper, iron, lead and nickel. Results indicated significantly higher contents of these metals in samples from gardens using wastewater when compared control samples. Significantly (p<0.05 & p<0.01)) higher levels of zinc ($24{\sim}122$ ppm) and iron ($208{\sim}683$ ppm) were noticed in mulberry leaves during summer followed by winter and rainy season. The significance of high content of heavy metals in mulberry leaves and cocoon yield pattern of this area in relation to the quality of irrigation water is discussed.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.171-178
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• 2003

Four thermo-tolerant lines of silkworm, Bombyx mori, (L.) viz., A HT, B HT (Chinese type) and F HT, G HT (Japanese type) were evolved by utilizing the breeding resource material (identified from initial screening at a temperature of 31 ${\pm} 1^{\circ}C$ and relative humidity 85 ${\pm}$ 5%) through conventional breeding. These tolerant lines were crossed with productive breeds and forty four hybrids were evaluated on eight economic traits by the Multiple Trait Evaluation Index Method. Ten hybrids were short-listed based on the average evaluation index value larger than 50 for eight economic traits studied. The identified ten hybrids recorded higher index values (＞ 50) for most of the traits studied. Single hybrid G ${\times}$ CSR12 indicated average index value larger than 50 for six traits viz., pupation number (58), cocoon weight (67), shell weight (65), average filament length (74), raw silk % (69), reelability % (51) except for shell ratio % (41). The standard deviation of the cocoons in the above hybrid was 8.41 in the hybrid cocoon length and width measurement. However, two selected hybrids viz., A ${\times}$ CSR5 and G ${\times}$ CSR13 recorded average index value larger than 50 for all the traits viz., pupation number (57, 60), cocoon weight (50, 54), shell weight (56, 57), shell ratio percentage (59, 53), average filament length (55, 60), raw silk percentage (63, 67) and reelability percentage (53, 53). The standard deviation of the cocoons in the two selected hybrids viz., A ${\times}$ CSR5 and G ${\times}$ CSR13 was 8.41 and 8.06 respectively in the cocoon length and width measurement.

• 한국잠사곤충학회지
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• 제32권1호
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• pp.8-16
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• 1990

누에 7개 품종을 이면교잡하여 얻은 F$_1$, 세대에 대한 잡종강세, 선발지수 그리고 유전적 진전 등을 분석한 결과는 다음과 같다. 잡종강세는 F$_1$세대에서 5령경과, 견층연감율의 자웅이 부의 방향을 나타냈고 견층비율을 제외한 전 형질이 20.90-37.60%로 정의 높은 강세율을 나타내었다. F$_2$에서는 견층비율, 견층연감율의 자웅이 부로, 그 외의 전 형질이 정의 강세율을 나타내었다. 선발지수는 선발의 최종대상형질을 견사량으로 하였을 때 F$_1$, F$_2$세대 모두 단일형질에서 단견중이 높았다. 선발대상형질을 5령경과, 단견중 견층중, fibroin량 등의 4개 형질로 하여 2, 3, 4형질을 조합하였을 때, 5령 경과와 단견중의 조합에서 선발가중치가 가장 크게 나타났다. 유전진전은 F$_1$, F$_2$세대에서 한일형질에서는 모두 견층중이 가장 높았고, 각 형질간의 조합에서는 전 형질을 조합하였을 때가 가장 높았다. 관계효율도 전 형질을 조합하였을 때가 가장 높았다.

• 한국잠사곤충학회지
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• 제43권1호
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• pp.29-32
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• 2001

At present, more than 300 races of the Silkworm are conserved and used as valuable genetic resources. But because of the uneffectiveness of manual data management, faster and systematic data base construction is needed. So, development of silkworm genetic resources management program has been begun and the result can be practically used. When developing the program, Visual basic was used for data input system construction, and MS Access for database. IIS(Internet Information System) and ASP(Active Server Page) was also used for searching data and information with Internet Web Server and Web Browser which is comfortable for constructing database and providing information. Data input item consists of 46 practical characteristics such as race name, moltinism, larval period and pupation percentage etc.. And these characteristics are classified with qualitative and quantitative character. Photographs of silkworm, cocoon and other related items were scanned and the image data was recorded on the database.

• 한국잠사곤충학회지
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• 제40권2호
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• pp.97-104
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• 1998

Mainly due to limited genetic resources available and also urgent need for hybrids suitable to local conditions, conventional theories and regular methods for bivoltine silkworm breeding are not easily applicable in such a tropical country as Sri Lanka which is recently planning to scale-up the silk industry. A simplified but practical methodology was introduced to overcome such constraints. Through application of such modified informal breeding methods, two hybrids named DP0308 and DP0314 were selected for cocoon production. Details of the altered method of germplasm improvement in the silkworm are presented, along with combining ability and heritability estimates for six parental pure lines in a half-diallel cross.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권1호
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• pp.44-52
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• 2002

To understand the relationship among different quantitative traits, correlation studies were performed by utilizing eighty-eight inbred strains of silkworm, Bombyx mori L. on twelve economic characters. Analysis resulted in correlation of 5th instar period with total larval period (r ＝ 0.7882), cocoon weight with shell weight (r ＝ 0.8326), shell weight with shell ratio (r ＝ 0.5067), shell ratio with raw silk ％ (r ＝ 0.7570), raw silk ％ with filament length (r ＝ 0.3490), filament size (denier) with reelability (r ＝ 0.3193) and boil-off loss % (r ＝ 0.2792). Negative correlation was observed among filament length with filament size (r ＝ 0.7582) and reelability with boil-off loss % (r ＝ -0.3236). Correlation of different quantitative characters for quality silk production is discussed.

• 한국잠사곤충학회지
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• 제55권1호
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• pp.11-21
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• 2019

Historical background and present status of Korean functional sericulture was reviewed. Five-year expansion projects began in 1962, and produced 41,700 tons of cocoon in 1976 and exported $271 million. However, the number of silkworm rearing households reduced to 59,800 by 1987 from 488,000 in 1976 due to rapid development of the secondary and the tertiary industries with higher labor cost. That's why functional sericulture was developed in Korea. Freeze-dried silkworm powder was found that it lowered the level of blood glucose. Nuedongchunghacho, Paecilomyces tenuipes, was cultured on silkworm larva. Odi, the fruit of mulberry trees, was studied as a new food ingredient. Mulberry tree varieties for improved Odi production were also developed.