• International Journal of Industrial Entomology and Biomaterials
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• 제8권2호
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• pp.181-187
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• 2004

Polyvoltine silkworm breeds/hybrids play an important role in tropical sericulture. In the process of synthesizing more potential polyvoltine hybrids(polyvoltine${\times}$bivoltine) of superior quantity and quality, the Andhra Pradesh State Sericulture Research and Development Institute (APSSRDI) has developed 8 promising polyvoltine breeding lines (SDMG2, APM16, APM15, APM14, APM5, RM2, APM3, APM13). In order to study their hybrid vigour and performance, these breeds were crossed with 4 potential bivoltine testers (SDD1, SDD2, SDD3, APS8), and 32 different hybrid combinations were prepared and evaluated for their mid parent heterosis (MPH) and better parent heterosis (BPH) of silk productivity. Since silk is the ultimate product required for commercial purpose, based on silk productivity and its heterosis, three superior polyvoltine hybrid combinations namely RM2${\times}$APS8 (24.3%), APM3${\times}$APS8 (12.4%) and APM15${\times}$SDD2 (10.8%) were adjudicated as potential heterotic hybrid combinations of superior silk yield and hence recommended for further large scale field trails and commercial exploitation.

• International Journal of Industrial Entomology and Biomaterials
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• 제27권1호
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• pp.131-141
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• 2013

At the interface of reducing agricultural income and increasing unemployment in agrarian economy of rural India, this article summarizes and evaluates the state of mulberry sericulture in northwest India, which includes Himachal Pradesh, Punjab, Rajasthan, Uttarakhand, and Uttar Pradesh. In $11^{th}$ plan period (2007-2012), there was an addition of 6 196 ha (217.09 %) of mulberry acreage at annual linier growth rate of 33.44%. However, total silk production could increase only by 54.64 MT (78.57%) at annual linier growth rate of 15.59 %, due to 43.93% (10.82 kg/ha) reduction in silk productivity at negative growth rate of -13.46%, annually. And now, average raw silk productivity in north-western states of India remains at 13.81 kg/ha, which is lower by 452.93 % (76.36 kg) in comparison to the national average of 100.90 kg/ha. Paper summaries the reasons for increasing cocoon yield gap at farmer's level and discuss the ways and means to increase raw silk productivity to improve the livelihood delivery of mulberry sericulture in northwest India.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권1호
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• pp.53-58
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• 2004

Studies on heterotic expression in the silk productivity of 66 thermo-tolerant bivoltine hybrids reared under high temperature $(36{\times}1^{\circ}C)$ and low humidity (60${\times}$5%) conditions revealed that manifestation of heterosis was highly significant for majority of the quantitative traits contributing to more cocoon productivity. Observations were made on 8 economically important traits such as fecundity, pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio, cocoon filament length and raw silk. Analysis of variance results revealed great deal of variability indicating significant (P < 0.001) variations. Out of 66 hybrids, 7 hybrids exhibited positive heterosis for seven traits and 4 hybrids expressed significant hetero-beltiosis for 6 traits, out of 8 traits evaluated. Based on results, the hybrids ${SR_1} {\times} {SR_5}and {CSR_2} {\times} {SR_5}$ are adjudged as most promising ones and can be exploited commercially in tropical climates to increase the cocoon productivity.

• 한국잠사곤충학회지
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• 제22권1호
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• pp.26-45
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• 1980

가잠의 견사물질 생성능력에 대한 견사선의 특이성을 구명코저 견사생산성이 다른 8개 원종과 그 F$_1$교잡종에 대하여 견사선의 성장 및 조직학적 특성, 후부견, 사선의 RNA 및 DNA합성과 그 아미노산조성 등을 조사한 결과 다음과 같을 결론을 얻었다. 1) 견사생성량이 다론 가잠품종간 F$_1$ 교배조를 만들 경우 다사량 품종은 5령유충기의 잠체중대 견사선중비 및 견사선중대 견사생성량비가 다사량 품종에 비하여 증가되었다. 2) 후부견사선의 조직학적 관찰에서 견사물질합성이 활발히 전개될 때는 세포핵의 크기 및 분지가 증대하고 5령 96시간째 세포핵의 형태에 있어서 견사생성량이 가장 적은 품종인 $N_2$ 및 $C_{60}$의 세포핵은 잠107, 잠108 등의 것에 비하여 크기가 작고 단순한 형태를 취하였다. 3) 가잠 후부견사선의 RNA함유율은 다사량계 품종이 소사량계 품종에 비하여 높았고 잠품종간 F$_1$ 교배조를 만들 경우 견사생성량과 RNA 함유율은 정상관으로 비례하였다. 4) 가잠 5령유충기중 5령 3일을 전후(2일~4일) 한 후부견사선의 RNA 및 DNA 생성량의 증가율은 다사량계품종이 소사량계에 비하여 약 30%정도 높았다. 5) 가잠 5령유충기(2~4일)의 후부견사선에 있어서 DNA에 의한 RNA 생성효율은 다사량계가 소사량 계품종에 비하여 높았다. 6) 다사량계 잠품종의 후부견사선 DNA 생성량은 5령 4일째 374$\mu\textrm{g}$/두인데 비하여 소사량계품종은 199$\mu\textrm{g}$로서 약 53%정도이었다. 7) 가잠 후부견사선의 아미노산 조성에 있어서 함유량이 가장 높은 것은 Alanine 34.8%이며 Glycine 22.8%, Serine 9.1%, Tyrosine 7.3%의 순으로서 견사 fibroin의 아미노산조성과는 달리 Glycine 함량이 Alanine에 비하여 적었다. 8) 가잠 원종과 교잡종의 후부견사선 아미노산 조성에 있어서 Valine, Isoleucine, Leucine, Phenylalanine, Lysine, Histidine 및 Arginine등 잠체성장에 대한 영양성 아미노산은 원종에 비교적 많이 함유되었고 Glycine Serine, Aspartic acid, Glutamic acid등 비영양성 아미노산과 Threonine은 F$_1$ 교잡종에 비교적 많이 함유되었다. 9) 견사 생성량이 다른 가잠 품종간의 F$_1$ 교배조에 있어서 후부견사선의 아미노산조성중 G.A.S.(Glycine+Alanine+Serine)함량은 다사량 품종일수록 증가되었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제1권2호
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• pp.79-86
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• 2000

Strengthening of R & D components of sericulture in India since the sixties has led to a quantum jump in silk production and presently India is the second largest producer in the world. This achievement is primarily due to a number of breakthroughs in R & D to match the requirements of tropics, by way of introduction of improved mulberry varieties and silkworm breeds, better mulberry cultivation and rearing management practices suited to tropical conditions. Of late, new approaches in molecular biology and biotechnology have also been vigorously pursued to strengthen the current conventional strategies. The present paper attempts to provide an overview of the present status of silk production in both mulberry and non-mulberry sectors, breakthroughs achieved through new approaches of biotechnology and the future prospects for maximizing silk productivity in India.

• 한국잠사곤충학회지
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• 제20권2호
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• pp.20-25
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• 1978

Research on the hormones of insect has followed by the special opportunities and problems arising from pollution. Since then, the main frame of it has been energetically exploited by ligation, decapitation and so on. In the meanwhile, knowledge of the biochemistry of hormone action as well as other aspects of biochemistry in insects has been gradually disclosed. Since 1966, practical use of active analogs of the hormones has been also worked out as an insecticide and brought the features of it to the light. On the other hand, it is expected to afford the increase of silk productivity resulted from control of the fifth larval period by delaying normal development. With these regards, some of analogs have been tried to apply practically to the silkworm. One of them is "Manta" produced by Zoecon Chemical Company and it is presently used for the increase of silk productivity in Japan. Another one is "R-20458", not registered one, issued by Stuffer Chemical Company. It is still pending for the silkworm growth regulator For the possibility of practical use, two chemicals are tested on the increase of silk productivity by topical application and the obtained results are summarized as follows. 1. It is evident that the fifth larval period was extended by topical application of the tested chemicals "Manta"and "R-20458"at the fifth instar after 51 hours of the last ecdysis, ranging from 12 hours to one day, as compared to. the control 2. In survival rates, there is no significance at 5% level between control and treatments. It proved that there was no toxity to silkworm by topical aprication. 3. There is an increase of cocoon yield in both chemical treatments. It was resulted from increase of weight of single cocoon. "Manta"2.5ppm produced 22.2kg of cocoon. It is equal to 9% increase in index, as compared to that of control. In case of R-20458, the increasing rates were varied at the different concentration; 21.4kg of cocoon production with 5% increase at 5ppm, 20.9kg of it with 2% increase at 2.5ppm and 20.6kg of it with 1% increase at 1. 25ppm in index, respectively, as compared with that of control. 4. Percentage of cocoon shell was increased by topical application. In case of "Manta" 2.5ppm, it is 25.6% which is equal to 6% increase in index, as compared with that of control. For "R-20458", the increasing rates of percentage of cocoon shell were varied with the different level of chemical concentration. They are 25.0% of 4% increase at 2.5ppm, 24.9% of 3% increase at 1.25ppm and 24.7% of 3% increase at 5ppm. 15% increase was attained at "Manta" 2.5ppm in the weight of cocoon layer based on cocoon yield and percentage of cocoon shell in index, as compared with that of control. The rates for "R-20458"are 5% increase at 2.5ppm and 4% increase at 1. 25ppm in index.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권1호
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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.

• International Journal of Industrial Entomology and Biomaterials
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• 제19권1호
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• pp.155-164
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• 2009

The most important factors in environment that influence the physiology of insects are temperature and humidity. Insects display a remarkable range of adaptations to changing environments and maintain their internal temperature (thermoregulation) and water content within tolerable limits, despite wide fluctuations in their surroundings. Adaptation is a complex and dynamic state that widely differs in species. Surviving under changing environment in insects depends on dispersal, habitat selection, habitat modification, relationship with ice and water, resistance to cold, diapause and developmental rate, sensitivity to environmental signals and syntheses of variety of cryoprotectant molecules. The mulberry silkworm (Bombyx mori) is very delicate and sensitive to environmental fluctuations and unable to survive naturally because of their domestication since ancient times. Thus, the adaptability to environmental conditions in the silkworm is quite different from those of wild insects. Temperature, humidity, air circulation, gases and photoperiod etc. shows a significant interaction in their effect on the physiology of silkworm depending upon the combination of factors and developmental stage affecting growth, development, productivity and quality of silk. An attempt has been made in this article to briefly discuss adaptation in insects with special emphasis on the role of environmental factors and their fluctuations and its significance in the physiology of mulberry silkworm, B. mori.

• International Journal of Industrial Entomology and Biomaterials
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• 제20권2호
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• pp.61-67
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• 2010

The bivoltine tropical tasar ecoraces of Antheraea mylitta Drury produces cocoons for seed production under seed crop rearing (July-August with $22{\sim}30^{\circ}C$ temperature and 50~70% relative humidity) and for silk production under commercial crop rearing (September-December with $17{\sim}27^{\circ}C$ temperature and 60~80% relative humidity). To consider the impact of hybrid vigour on egg, larva, cocoon and silk related commercial traits, the $F_1$ hybrids made among Daba, Jata and Raily ecoraces were assessed successively for three years. The hybrid vigour in the $F_1$ hybrid of Daba$\times$Jata ($T_7$) was positive for egg fertility (+23.1%), shell weight (+25.6%), silk yield (+79.0%) and filament length (+68.1%), with filament of high denier (11.98d) and reduced larval span (-7.1%). The Jata$\times$Daba ($T_8$) hybrid has shown negative heterosis in egg fertility (-8.0%) compared to the other F1 hybrids, Daba$\times$Raily ($T_9$) and Raily$\times$Daba ($T_{10}$), when they rise simultaneously during the commercial crop season. The better performance of parental ecoraces ($T_4$ to $T_6$) in their commercial traits during commercial crop over parents of seed crop ($T_1$ to $T_3$) and the superior performance of $F_1$ hybrids ($T_7$ to $T_{10}$) over parents of commercial crop ($T_4$ to $T_6$) during commercial crop season indicates the apparent hybrid vigour in tasar $F_1$ hybrids. As the Daba$\times$Jata ($T_7$) and Jata$\times$Daba ($T_8$) $F_1$ hybrids have shown highest hybrid vigour, their rearing during commercial crop can optimize the silk productivity and commercial sustenance of the tasar silk industry.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 1997년도 Progress and Future Development of Sericultural Science and Technology 40th Anniversary Commemoration Symposium
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• pp.1-21
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• 1997

Silk is praised "Queen of Fiber", which wrote a glorious page in the history of human adornment culture. Thanks to the development of science and technology, silk production has been increased dramatically during last half century. Nowadays, as "Healthy Fiber" silk lets all the globe to be forming the "Silk Boom" Like in other scientific fields, a great deal of progress has been made in sericultural science and technology, which also accelerated the development of multipurpose utilization of sercultural recourses. The main tendency of the sericulture development is raising the quality of cocoon, and at the same time, increasing the output per unit mulberry area and labor production efficiency. The chief measure of raising the cocoon quality is breeding and selecting the new mulberry and silkworm varieties, preventing and curing the diseases and pests and improving the environment of mounting, and the symble for increasing the labor productivity is carrying out the technological system of saving labor and operation ease, and enlarging the production scale. As a natural protein fiber, silk will be still a favorite with human in the next century, because its structure and properties can not be replaced by other any fiber. The 21st century is the biological time, and measures of developing sericulture will use the achievement on the field of molecular biology and biotechnology to carry out the molecular breeding, development regulating, silkworm rearing industrializing, exploiting the new silk and its new usage, utilizing the sericultural resources, and producing the special protein from silkworm as a host of expressing exogenous genes so that make the sericulture to contribute more what it can do for the human being.