Abstract
Phenotypically striped (+/ps) F1 individuals of several silkworm strains were irradiated with 4000r (1210r/min) in different stages viz., advanced embyronic stage, first, second and third larval stages in order to investigate the number and size of spots due to the elmination of ps-carrying chromosome fragment.
Spots were not visible on the body of larvae given X-ray treatment in the third larval stage.
It was found that the number of spots was maximum, medium and minimum in individuals X-rayed in second larval, first larval and advanced embryonic stages.
As regards the size of the white spots experimental results indicated that it decreases with an advancement of X-irradiated stage of growth in the silkworm.
Number and size (diameter in microns) of spots do not appear to be correlated and interdependent. It may plausibly be thought that these two phenomena are controlled by different mechanisms.
