Seasonal Variations in the Silk Yield Contributing Characters of Forty-two Strains of the Silkworm, Bombyx mori (Lepidoptera: Bombycidae)

Forty-two strains of the silkworm, Bombyx mori (L.), collected from China, Japan, Vietnam, South Korea, Brazil, India, and France were reared in the spring, summer and autumn seasons during 1991–92 at the Regional Station of Central Sericultural Research and Training Institute, Coonoor, Tamilnadu State, India. Analyses were made on five silk yield-contributing characters, namely pupation rate, cocoon weight, shell weight, cocoon shell ratio, and silk filament length. Results indicated the superiority of the following strains for all the above mentioned characters: 14M and JC2P (in spring); NBJPO and JC2P (in summer); and M2, NBJPO and SPJ2 (in autumn). The importance of rearing a given strain of silkworm in the optimal season for its maximum economic value in terms of silk yield is discussed.

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Stability and path analysis for yield and related traits in silkworm, (Bombyx mori L.) reared under stress conditions

Genetika ◽

10.2298/gensr1601271c ◽

2016 ◽

Vol 48 (1) ◽

pp. 271-284

Author(s):

N. Chandrakanth ◽

S.M. Moorthy ◽

M. Rekha ◽

V. Sivaprasad

Keyword(s):

Bombyx Mori ◽

High Temperatures ◽

Analysis Of Variance ◽

Path Coefficient ◽

Larval Weight ◽

Stability Parameters ◽

Shell Weight ◽

Pupation Rate ◽

Bombyx Mori L ◽

Silkworm Bombyx Mori

The silkworm, Bombyx mori L. is a poikilothermic organism whose growth and development is adversely affected by high temperatures. Rearing of silkworm at high temperature conditions of tropical countries like India causes extensive crop loss by reducing cocoon yield. Breeding new silkworm breeds tolerant to high temperatures is the most effective and economical method to increase cocoon yield. Introduction of stable genotypes in such breeding programs and knowledge on the relationships between cocoon yield and other traits would be more advantageous in increasing cocoon yield at high temperatures. Therefore, in this study twenty silkworm genotypes were reared in five artificially simulated environments with different temperatures ranging from 25?C to 38?C. Based on coefficient of variation (%) values, the traits cocoon yield / 10,000 larvae by weight (CY) and cocoon weight showed maximum and minimal variation among the traits in all the five environments. Analysis of variance revealed a substantial genetic variability among the genotypes for most of the traits studied. The results of combined analysis of variance showed significant differences over traits indicating that the traits are influenced by genotype ? environment interactions. Stability analysis with respect to CY showed higher mean value compared to grand mean, regression coefficient equal to unity and less deviation from regression in ATR16, CSR17, BHR2, S-5 and D13 genotypes, suggesting that they are consistent with the CY over the different environments. Clustering based on the stability parameters resulted in separation of twenty silkworm genotypes into 5 clusters based on their ability to tolerate high temperatures. Correlation studies demonstrated positive and significant (P < 0.05) correlations between CY and other traits. Pupation rate was most positively associated with CY followed by larval weight, cocoon weight, cocoon shell weight and cocoon shell percent. Path coefficient analysis also revealed that the pupation rate had the maximum direct effect on CY followed by cocoon shell weight and larval weight. Cocoon shell percent and cocoon weight exhibited negative direct path effect on cocoon yield / 10,000 larvae by weight. Therefore, the selection based on pupation rate, larval weight and cocoon shell weight can be effective in improving cocoon yield in silkworm at different environments with varying temperature.

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Influence of Supplementation of Zea Mays Flour on the Growth and Economic Traits of Silkworm, Bombyx Mori L.(PFD)

IRA-International Journal of Applied Sciences (ISSN 2455-4499) ◽

10.21013/jas.v3.n3.p17 ◽

2016 ◽

Vol 3 (3) ◽

Author(s):

Shifa Vanmathi. J

Keyword(s):

Zea Mays ◽

Bombyx Mori ◽

Pupal Weight ◽

Filament Length ◽

Economic Traits ◽

Mulberry Leaves ◽

Flour Protein ◽

The Impact ◽

Silk Filament ◽

Silkworm Bombyx Mori

<div>Studies were carried out on the impact of supplementation of Zea mays flour on silkworm Bombyx mori belonging to double hybrid variety (PFD). The 3rd,4th 5th instars larvae were feed with leaves supplemented with different concentrations of Zea mays flour. Maximum larval weight was observed in 5th instar larvae in 10% Treatment (4.59±0.31g ) and 5% Treatment (3.98±0.23g ) as compared to the control (3.13± 0.14g ).Mulberry leaves treated with Zea mays flour protein (10%)fed larvae recorded a maximum cocoon weight (2.32±0.07g), pupal weight (1.53±0.12g) shell weight (0.42±0.02g) , shell ratio (24.55±0.62%) silk filament length (851.11±6.94m) silk filament weight (0.51±0.04g). Shell ratio in this treatment (10%) showed an increase of 18.38 % over control filament length 21.64% . Larvae fed with mulberry leaves enriched with Zea mays flour protein showed significant enchancement in economic characters of Bombyx mori was traced. </div>

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Controlling of bacterial and fungal diseases that contaminating mulberry silkworm, Bombyx mori by using some plant extracts

Bulletin of the National Research Centre ◽

10.1186/s42269-019-0218-3 ◽

2019 ◽

Vol 43 (1) ◽

Author(s):

Mahmoud S. I. Saad ◽

Enas M. Y. Elyamani ◽

Walaa M. M. Helaly

Keyword(s):

Bombyx Mori ◽

Larval Mortality ◽

Pupal Weight ◽

Filament Length ◽

Larval Weight ◽

Shell Weight ◽

Cocoon Production ◽

Black Seed ◽

Mulberry Silkworm ◽

Silk Filament

Abstract Background Mulberry silkworm, Bombyx mori L. is one of the most economically important insect because its production of silk which interfere with many important industries. Diseases of the silkworm, B. mori such as viral, bacterial, fungal and protozoan pathogens seriously affect their cocoon production. Bacterial and fungal pathogens independently cause the highest cocoon loss, so the use of botanicals is considered an important strategy to control diseases of silkworm. Results The artificially infected silkworm, B. mori larvae with Bacillus thuriengiensis when treated with concentrations of 2 and 3% of black seed and basil leaves extracts increased significantly larval weight and decreased larval mortality. In addition, 3% basil leaves extract and 1% of black seed increased pupal weight. Cocoon weight and cocoon shell weight increased significantly by 3% basil leaves extract treatment. All tested concentrations of black seed extract increased the silk ratios of the resulted cocoons as compared to the infected control. For technological parameters, all tested extracts at 3% concentration caused the highest silk filament length; meanwhile control larvae recorded the highest silk filament weight and size. Regarding the mulberry silkworm, B. mori artificially infested with conidial solution of Beauveria bassiana when treated with all concentrations of the tested plants showed an enhancement in larval weight, pupal weight, cocoon weight, cocoon shell weight, silk filament length, and filament weight and reduced the larval mortality percentage. The highest silk filament size were recorded for the control group. Conclusions Tested concentrations of Morus alba, Ocimum basilicum leaves extracts and Nigella sativa seeds extract have suppressed the bacterial and fungal disease spread when used three times through both 4th and 5th larval instars. Moreover, the biological characters and technological traits enhanced by using of these extracts, so it can be used in sericulture for improving cocoon crop quality and quantity.

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Diallel cross analysis of filament length in the silkworm, Bombyx mori L.

Journal of the Asiatic Society of Bangladesh Science ◽

10.3329/jasbs.v38i2.15616 ◽

2013 ◽

Vol 38 (2) ◽

pp. 247-255

Author(s):

HA Rashid ◽

SM Rahman ◽

MK Ahsan

Keyword(s):

Bombyx Mori ◽

Dominance Effect ◽

Diallel Analysis ◽

Diallel Cross ◽

Filament Length ◽

Narrow Sense Heritability ◽

Reciprocal Effect ◽

Wide Range ◽

Bombyx Mori L ◽

Silkworm Bombyx Mori

A diallel analysis for filament length in six varieties of silkworm, Bombyx mori L. having a wide range of variability has been genetically analysed by means of 6×6 diallel cross. The results indicated that both additive and non-additive genetic variations were important for determining the expression of this trait. Besides the dominance, deviation of genes present in this diallel existed predominantly in one direction and they were independent of reciprocal effect and some of the parents contained more dominant than recessive alleles in S-1 and S-3. The presence of specific dominance effect which were peculiar to individual crosses and a significant part of it was independent of reciprocal effect. The regression of filament length is deviated significantly from unity in majority of the seasons (except S-4) giving a contrasting result implying the presence of nonallelic interaction. The distribution of genes for two seasons (S-2 and S-3) was not symmetrical, while the rest two seasons (S-1 and S-4) showed symmetrical distribution of positive and negative among the parents. In narrow sense heritability was found to be medium to high and the broad sense heritability was high among the studied varieties. DOI: http://dx.doi.org/10.3329/jasbs.v38i2.15616 J. Asiat. Soc. Bangladesh, Sci. 38(2): 247-255, December 2012

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The QTLs, Determination of Cocoon Shell Weight Trait in Mulberry Silkworm (Bombyx mori L.)

Biotechnology(Faisalabad) ◽

10.3923/biotech.2010.41.47 ◽

2009 ◽

Vol 9 (1) ◽

pp. 41-47 ◽

Cited By ~ 1

Author(s):

A.R. Bizhannia ◽

S.Z. Mirhossein ◽

B. Rabiee ◽

M. Taeb

Keyword(s):

Bombyx Mori ◽

Shell Weight ◽

Bombyx Mori L ◽

Mulberry Silkworm ◽

Weight Trait ◽

Silkworm Bombyx Mori

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Effects of methionine and tryptophan on some economic characters in the mulberry silkworm Bombyx mori L

University Journal of Zoology Rajshahi University ◽

10.3329/ujzru.v25i0.328 ◽

1970 ◽

Vol 25 ◽

pp. 57-62

Author(s):

Rezina Laz ◽

Ataul Gani ◽

AM Saleh Reza

Keyword(s):

Amino Acids ◽

Key Words ◽

Bombyx Mori ◽

Growth Parameters ◽

Pupal Weight ◽

Filament Length ◽

Bombyx Mori L ◽

Mulberry Silkworm ◽

Silkworm Bombyx Mori

Methionine and tryptophan were supplemented with food at four concentrations viz. 250, 500, 750 and 1000 ppm to evaluate the effects of these amino acids on the larval and pupal weight and different cocoon characters in the mulberry silkworm, Bombyx mori L. Treatments significantly enhanced the performance of all the parameters in both parental and F1 generations except the filament denier. Significant differences were also observed between the generations of all the parameters except the filament length. However, the highest concentration (1000 ppm) of both the compounds decreased the growth parameters in comparison to control. Key words: Bombyx mori, methionine, tryptophan, growth, filament length Univ. j. zool. Rajshahi Univ. Vol.25 2006 p.57-62

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Effects of Minerals on Growth of Silkworm, Bombyx mori L. and Their Impact on Cocoon Economic Parameters

Madras Agricultural Journal ◽

10.29321/maj.10.000487 ◽

2021 ◽

Vol 108 (March) ◽

pp. 1-5

Author(s):

MURUGESH K.A ◽

◽

ARUNA A ◽

CHOZHAN K ◽

◽

...

Keyword(s):

Potassium Chloride ◽

Bombyx Mori ◽

Magnesium Sulphate ◽

Zinc Sulphate ◽

Pupal Weight ◽

Shell Weight ◽

Mulberry Leaves ◽

Economic Parameters ◽

Bombyx Mori L ◽

Silkworm Bombyx Mori

The present study aimed at increasing the cocoon yield by fortifying the mulberry leaves with minerals such as zinc sulphate, magnesium sulphate and potassium chloride at different concentrations (10, 25, 50, 100 and 200 ppm) and feeding them to the silkworm Bombyx mori L. The oral application of minerals through mulberry leaves to silkworm larva during lateage instars significantly improved its larval and cocoon economic parameters. Among the five concentrations tested, it was observed that the zinc sulphate @ 100 ppm, magnesium sulphate @ 200 ppm and potassium chloride @ 100 ppm registered significantly higher mature larval weight, effective rate of rearing (ERR), cocoon weight, pupal weight, shell weight and shell ratio than the control. Per os administration of minerals also significantly reduced the fifth instar larval duration of silkworm.

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