Recovery from genetic damage induced by 4 krad X-rays in sperm of Tetranychus urticae Koch (Acari, Tetranychidae)

Abstract

When males of Tefranychus urticae (Koch) were irradiated with 4 krad X-rays, there was a significant decrease of dominant lethals in broods from matings 7 to 13 days after irradiation. No recovery of dominant lethals was observed in sperm which was stored in the female. There was also no effect on the fertility of F,-females following storage of sperm in the female. A significant increase of fertility of Fi-females was observed after successive mating of the irradiated males. A peak frequency of semi-sterile F r -females, which are supposed to be heterozygous for structural chromosome mutations, was observed in broods from males, 7 days after irradiation. The following spennatogenic stages were studied: mature sperm, late and early spermatids, and spermatogonia.Mature sperm is the most sensitive spermatogenic stage to the induction of dominant lethals and factors causing sterility and infecundity in F r -females. Early spermatids are the most sensitive spermiogenic stage for the induction of factors which cause semisterility in F r -females.