International Journal of Industrial Entomology and Biomaterials

Korean Society of Sericultural Science (한국잠사학회)
권호 표지

Heterotic Expression in Silk Productivity of Newly Evolved Thermo-tolerant Bivoltine Hybrids of Silkworm Bombyx mori L.

  • Rao, P.Sudhakara (Central Sericultural Research and Training Institute) ;
  • Datta, R.K. (Director (Retired)) ;
  • Vijaya Kumari, K.M. (Central Sericultural Research and Training Institute) ;
  • Palit, A.K. (Central Sericultural Research and Training Institute) ;
  • Haque Rufaie, S.Z. (Division of Sericulture, S. K. University of Agricultural Sciences and Technology)
  • Published : 2004.09.01
Download PDF
⟨ Previous Next ⟩

Abstract

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.

Keywords

References

  1. Basavaraja,H. K. (1996) Studies on the synthesis of productive bivoltine strains of Bombyx mori L. through hybridisation, selection and genetic evaluation. Ph. D. Thesis, University of Mysore, Mysore
  2. Bhargava, S. K., V. Thiagarajan and E. Rajalaxmi (1996) Het-erotic expression in silk productivity of different crosses of silkworm Bombyx mori L. Indian Vet. J. 73, 176-180
  3. Falconer, D. S. (1981) Introduction to quantitative genetics ($2^{nd}$ edition.) Longman press, London
  4. Garno, T. (1976) Recent concepts and trends in silkworm breeding. Farming Japan 10, 11-22
  5. Gamo, T. and T. Hirabayashi (1983) Genetic analysis of growth rate, pupation rate and some quantitative characters by diallel crosses in silkworm, Bombyx mori L. Japan J. Breed. 33, 178-190 https://doi.org/10.1270/jsbbs1951.33.178
  6. Griffing, B. (1956) Concepts on general and specific combin-ing ability in relation to diallel crossing systems. Aust. J. Biol. Sci. 9, 463-493 https://doi.org/10.1071/BI9560463
  7. Harada, C. (1961) On the heterosis of quantitative characters in Silkworm. Bull. Seric. Expt. Stn. 17, 50-52
  8. Hirobe, T. and H. Ohi (1954) On the studies of heterosis in the Bomyx mori L. Japan J. Breed. 4, 1-4 https://doi.org/10.1270/jsbbs1951.4.1
  9. Krishnaswami, S. (1978) New technology of silkworm rearing. CSRTI Bulletin, Central Silk Board 2, 1-23
  10. Ramesh Babu, M. Chandrashekharaiah, H. Lakshmi and J. Prasad (2001) Expression of hybrid vigour for silk produc-tivity in silkworm, Bombyx mori L. J. Exp. Zool. India 4, 317-321
  11. Subba Rao, G., S. K. Sen, B. Ghosh and S. K. Das (1990) Het-erosis in some indigenous hybrids and bivoltine races of mulberry silkworm, Bombyx mori L. Perspect. Cytol. Genet. 7, 1043-1054
  12. Suresh Kumar, N., T. Yamamoto, H. K. Basavaraja and R. K. Datta (2001) Studies on the effect of high temperature on $F_1$ hybrids between polyvoltine and bivoltine silkworm races of Bombyx mori L. Int. J. Indust. Entomol. 2, 123-127