Embryonic Development and Induced Dominant Lethality in F 1 Eggs of Chilo partellus (Swinhoe)

Abstract

Observations were made on the embryonic development of fertilized eggs from unirradiated parents and parents whose males were irradiated at 10 and 15 kR or females at 10 kR. The observations were also made on unfertilized eggs laid by virgin females. Phenotypically, no difference was observed in color, general appearance, and embryonic development of 1-day-old eggs from all the matings; eggs laid by virgin females, however, had wrinkled surfaces and showed no sign of embryonic development (hollow center). Recognizable differences in embryonic development were observed 2 days after laying, when the embryos from normal females mated with irradiated males and irradiated females mated with normal males did not develop the orange spots which were visible in all the eggs from unirradiated parents. The embryonic development of eggs from irradiated females mated with normal males was much more affected than eggs from normal females mated with irradiated males; however, in both cases most of the dominant lethals acted late in the development.