Journal of Genetics

, 52:140 | Cite as

Delayed effects in chromosome breakage by x-rays intradescantia bracteata

  • K. C. Bora


  1. 1.

    X-ray fractionation experiments have been made with varying intervals which separate two dose fractions.

  2. 2.

    Effects of a range of intensities on the yield of chromosome aberrations due to the two dose fractions separated by different time intervals have been studied.

  3. 3.

    The experiments provide evidence for delayed action in the breakage of chromosomes by X-rays.

  4. 4.

    The average life of a break to remain open has been found to be short (a few minutes), but it is probable that a break can occasionally remain open for many hours.

  5. 5.

    The effects of varying intensities upon the breakage process have been discussed. I am greatly indebted to Professor J. S. Mitchell for his continued interest and help, to Professor D. G-. Catcheside for his helpful introduction to the scoring methods and to Dr P. C. Koller for valuable criticisms. To Miss R. D. Saunders and Mr L. Gurner my thanks for their technical assistance.


A financial grant from the Government of India and Assam made this work possible.


Chromosome Aberration Dose Fraction Chromosome Breakage Continuous Dose Adiol 


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Copyright information

© Indian Academy of Sciences 1954

Authors and Affiliations

  • K. C. Bora
    • 1
  1. 1.The Botany School and the Department of RadiotherapeuticsUniversity of CambridgeUK

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