Unchanged recovery of crossovers after x-irradiation of pupal Habrobracon.

mothers heterozygous for four linked markers showed no significant variation between females, or within age groups from ages 2 to 38 days, or foilowing x-radiation doses of 1000 r, 2000 r, or 3000 r to the white pupal stage. Total fertility was increased among lower dosage females and was drastically reduced in the 3000 r group. The constancy of recombination in the wasp was attributed to the lack of synaptic chromosomes in gonial cells rather than to radioresistance of chromosomes or to complete selection against pseudocrossovers in haploid larvae and pupae. (auth)